Qualification: 
MS, MCh
praveenv21204@aims.amrita.edu

Dr. Praveen Varma completed his MBBS in 1992 and MS General Surgery in 1996 from Calicut Medical College, Kerala. He completed MCh from Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum in 2000. Then, he joined Medical College, Trivandrum as Lecturer in Cardiac Surgery. He worked as Assistant Professor in Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum till 2005.

Then he joined as Resident in Cardio-Thoracic Surgery at Boston Medical Center, Boston University and he also served as Chief Resident till 2008. At BMC, he gained more experience in CABGs, Mitral Valve Repair and surgeries for Aortic root.

He worked as senior clinical fellow Brigham and Women’s Hospital, Harvard Medical School for 2 years. At Brigham, he gained experience in Minimally Invasive Mitral Valve Repair and AVR, complex reoperation surgeries, Heart Failure surgeries including Transplantation and Ventricular Assist Device placement.

He was appointed as an Additional Professor in Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum by the senior staff selection committee.

He is currently working as the Professor and Head of the Department of Cardiovascular & Thoracic Surgery at Amrita Institute of Medical Sciences and Research Center, Kochi. His specific areas of interest are beating heart CABG, Ischemic Mitral Regurgitation correction, Mitral valve and Tricuspid valve repair, extended septal myectomy for Hypertrophic Cardiomyopathy, surgery for infective endocarditis and Heart Transplantation. He has been actively involved in resident education.

He is also a reviewer for numerous journals and is also the Editorial Board member of Annals of Cardiac Anesthesia. He has co-authored close to 50 publications in various journals.

Education and Professional Experience

  • 2010 September - 2014 September: Additional Professor, CVTS, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum.
  • 2008 July -2010 June: Senior Clinical Fellow, Division of Cardiac Surgery, Brigham & Women’s Hospital, Harvard University, Boston, MA, USA
  • 2008 January -2008 June: Chief Resident, Cardio-Thoracic Surgery, Boston Medical Center, Boston University, Boston, MA, USA.
  • 2006 July -2007 December: Clinical Resident, Cardio-Thoracic Surgery, Boston Medical Center, Boston University, MA, USA.
  • 2005-2006: Passed USMLE Step1 (score-99) in July, Step2 CK (score-99) in September, Step 2CS in November, Step3 (score-95) in February. ECFMG
  • 2001 June-2005 March: Assistant Professor of Cardio-Thoracic and Vascular Surgery, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India.
  • 2001 January-2001 June: Lecturer in Cardiac Surgery, Medical College, Trivandrum, India.
  • 1998 January- 2000 December: Residency in Cardiothoracic and Vascular Surgery, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India.
  • 1996 October-1997 September: Registrar in Cardiac Surgery, Kovai Medical Center and Hospital, Coimbatore, India.
  • 1993-1996: MS General Surgery, Calicut Medical College.
  • 1986-1992: MBBS, Calicut Medical College.

Publications

Publication Type: Journal Article

Year of Publication Title

2020

Dr. Praveen Varma and Ahamed, H., “Abnormal mitral valve apparatus is not an indication for mitral valve replacement in hypertrophic obstructive cardiomyopathy”, Annals of Cardiac Anaesthesia, vol. 23, no. 2, pp. 246-247, 2020.[Abstract]


We read with interest the article by Aggarwal et al. [1] about the intraoperative echocardiography detection of abnormal mitral valve apparatus in a patient scheduled for surgery for hypertrophic obstructive cardiomyopathy in the latest issue of Annals. The authors need to be congratulated for detecting the various abnormalities of the mitral valve apparatus by intraoperative transesophageal echocardiography; however, we feel that the concomitant mitral valve replacement along with septal myectomy was probably unwarranted.

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2020

Theertha M., S., S., Priya, V. V., Jain, P., Dr. Praveen Varma, and Dr. Ullas Mony, “Innate Lymphoid Cells: Potent Early Mediators of the Host Immune Response During Sepsis”, Cellular and Molecular Immunology, 2020.

2019

L. Sreedharan, Krishna, N., Gopalakrishnan, U., and Dr. Praveen Varma, “Successful surgical repair of aorto-esophageal fistula due to fish-bone ingestion”, Indian J Thorac Cardiovasc Surg, vol. 35, no. 1, pp. 68 - 70, 2019.[Abstract]


Aorto-esophageal fistula is a rare and potentially lethal disease. The main causes are ruptured aortic aneurysm, foreign body ingestion, complication of surgical or endovascular repair of thoracic aortic aneurysm, and esophageal malignancy. We report a case caused by fish-bone ingestion. He underwent replacement of proximal descending aorta using circulatory arrest and trans-hiatal esophagectomy in the same sitting. A second-stage esophago-coloplasty was performed after 6 months for establishing digestive tract continuity.

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2019

Dr. Ullas Mony, S., S., Jain, P., K., S., Sebastian, A., Theertha M., Dr. Neeraj Siddarthan, and Dr. Praveen Varma, “Detection of Dysregulated Host Response By Flow Cytometry May Pre-Empt Early Diagnosis of Sepsis after Cardiac Surgery”, Blood, vol. 134, pp. 4863-4863, 2019.[Abstract]


INTRODUCTION Sepsis is a life-threatening organ dysfunction caused by dysregulated host response to infection. Early detection of sepsis is very crucial in its management, as there is an increase of 8\% mortality for every hour delay in commencing therapy (Kumar et al., 2006). A wide variety of diagnostic techniques proposed, could not be clinically translated due to poor sensitivity \& specificity, high levels of heterogeneity and complexity of assay preparation. Currently most clinical settings depend on Procalcitonin (PCT) and C-reactive protein (CRP) for diagnosis, which also lack sensitivity and specificity.The objective of our study was early detection of sepsis in patients undergoing cardiac surgery. Blood stream infection, confirmed by blood culture (the gold standard), requires large turnaround time and is less sensitive here due to prophylactic antibiotics. SOFA score overestimate the probability of sepsis due to the impaired cardiovascular parameters and inotrope support (Howitt et al., 2018). The Society of Thoracic Surgeons (STS) criteria to detect sepsis need positive blood culture to identify sepsis within the first 48 hours post-surgery. Since none of the above can cater early diagnosis, the most appropriate way is to target dysregulated host response. It has been reported that increased expression of CD64, on neutrophil surface (nCD64) is associated with proinflammatory response and down-regulation of HLA-DR expression on circulating monocytes (mHLA-DR) is associated with anti-inflammatory response in humans. Citing this interplay between pro and anti-inflammatory response in sepsis, we hypothesized that the relative expression of these antigens may detect dysregulated host immune response and thereby may provide a criterion for early diagnosis of sepsisMATERIALS AND METHODSA flowchart of the experimental steps is shown in Fig1. Adult patients, who underwent cardiac surgery, were selected for this double-blinded study after the approval from the appropriate Institutional Ethics Committee. The study was un-blinded after the initial set of experiments, with biochemical and clinical outcome of the patients. The data sets were analyzed (GraphPad Prism v8.1.1) and a p value of \< 0.05 was considered statistically significantRESULTSOut of the total patients (n=33), 7 patients were diagnosed with suspected sepsis and 1 with proven sepsis as per STS criteria, substantiated by longer ICU and hospital stay (Table1). The optimized Flowcytometry panel and gating strategies is shown in Fig.2The expression of nCD64, mHLA-DR and SI (Sepsis Index) in all patients before surgery did not show any statistically significant difference with that of healthy controls [Figure-3A]. At 24 hours post-surgery, all patients had significant up-regulation of nCD64 and down-regulation of mHLA-DR. A similar significant elevation was observed in CRP and PCT [Figure-3 B-D], but insignificant difference exists between sepsis and non-sepsis patients (p values in Table1). Therefore the diagnostic efficacy of all this measurements and scoring scheme, in identifying sepsis at 24 hours was poor (Table2)A useful diagnostic criterion is obtained by calculating the fold increase in nCD64 (I64) \& SI (ISI) and fold decrease in mHLA-DR (DHLA) at 24 hour. It was observed that many patients had ISI≥10, due to I64 approximately 2 and DHLA 5. Based on this observation, a diagnostic criterion able to detect 'dysregulated host immune response' at 24 hour post-surgery is identified. The criterion is: 10 fold or more increase in SI combined with either ≤1.8 fold increase in nCD64 or ≤5.2 fold decrease in mHLA-DR.CONCLUSIONThe data obtained from this pilot study was analysed based on different criteria to identify the best possible way to detect the onset of sepsis post-cardiac surgery. The discriminative power of many tests to differentiate sepsis and SIRS is inadequate. We propose a combination of fold changes in antigen expression, which could so far, identify all sepsis patients, since the measurements detect the underlying biological mechanism, picking up both exacerbated proinflammatory response and immunoparalysis. The significance of the result is that the proposed diagnostic criteria could potentially pre-empt diagnosis of sepsis at 24 hours post-surgery, before the onset of any clinically identifiable symptoms of the disease. This needs to be substantiated by extending the study on a larger patient cohort.Mony:BD Biosciences: Research Funding. Jain:BD Biosciences: Employment.

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2019

N. M. Sundaram, Kalyani, E., Amirthalingam Sivashanmugam, Dr. Ullas Mony, Dr. Praveen Varma, and Dr. Jayakumar Rangasamy, “Injectable Nano Whitlockite Incorporated Chitosan Hydrogel for Effective Hemostasis”, ACS Applied Bio Materials, vol. 2, pp. 865-873, 2019.[Abstract]


Uncontrolled bleeding can lead to many complications that might cause multiple organ failures and even death. Of all the hemostatic agents used, chitosan has been reported to show better hemostatic potential. It acts through one mechanism involved in hemostasis that is plug formation by adhering to the injured site. Hence our focus is to enhance the hemostatic potential of chitosan (Ch) hydrogel by incorporating nano whitlockite (nWH: Ca18Mg2(HPO4)2(PO4)12) that would release Ca2+, Mg2+, and PO43– ions that would simultaneously initiate the coagulation cascade. Ch-nWH composite hydrogel can act simultaneously on different mechanisms involved in hemostasis and bring about rapid bleeding control. The nWH particles were synthesized using precipitation technique and were characterized. Particle size of nWH was found to be 75 ± 5 nm. Composite hydrogel was characterized using FTIR and XRD to confirm the presence of different constituents of the hydrogel. Rheological studies showed the shear-thinning property and increased elastic modulus of the composite hydrogel compared to Ch hydrogel. 2%Ch-4%nWH hydrogel was observed to be cytocompatible with Human Umbilical Vein Endothelial Cells (HUVEC). In the in vitro blood clotting analysis using citrated human whole blood, 2%Ch-4%nWH hydrogel showed rapid blood clot formation compared to control 2%Ch hydrogel. Further in vivo experiments performed on liver and femoral artery injuries created on Sprague–Dawley (S.D) rat model reveals that 2%Ch-4%nWH hydrogel promoted rapid bleeding control and less volume of blood loss compared to Ch hydrogel. These in vitro and in vivo results showed that incorporation of nWH has enhanced the hemostatic potential of Ch hydrogel. Therefore, the synthesized 2%Ch-4%nWH hydrogel may be a promising system that could bring about rapid hemostasis during life threatening bleeding.

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2019

A. Ghurram, Krishna, N., Bhaskaran, R., Kumaraswamy, N., Jayant, A., and Dr. Praveen Varma, “Patients who develop post-operative atrial fibrillation have reduced survival after off-pump coronary artery bypass grafting”, Indian Journal of Thoracic and Cardiovascular Surgery, vol. 36, no. 1, pp. 6–13, 2019.[Abstract]


Objective: Post-operative atrial fibrillation (POAF) increases hospital stay, resource utilization, morbidity, and mortality. However, there is paucity of data about its effect in Indian patients undergoing off-pump coronary artery bypass grafting (CABG). Methods: Seven hundred forty-eight patients underwent off-pump CABG from January 2015 to December 2016 (24 months). One hundred twenty-seven patients (16.7%) developed POAF. In an effort to mitigate the effects of wider risk factors on perioperative outcomes, a separate sub-analysis of patients based on risks quantified by EuroSCORE II (<> 3) was also performed. Results: Age > 60 years and development of sepsis were the independent predictors for the development of POAF. Thirty-day/mortality rate was higher in the POAF group (7.1% vs. 1.4%; p value < 0.001). POAF was associated with increased ICU and hospital stay and increased incidence of stroke and renal dysfunction. The survival was significantly lower in the POAF group compared with the normal sinus rhythm (NSR) (3-year survival in POAF was 81.3% vs. 94.4% in the NSR group; Hazard ratio (HR) 3.867 (1.989–7.516)). Intra-aortic balloon pump (IABP) usage, age ≥ 60 years and sepsis were independent predictors for the development of POAF in low-risk patients. For the NSR group, 1-year survival was 98% and 3-year survival was 95.7%. For the POAF group, 1-year survival was 94.4% and 3-year survival was 84.0% (HR. 3.794 (1.897–7.591)). Conclusion: The incidence of POAF was lower than reported in the wider global literature. Increasing age and development of post-operative sepsis were strong independent predictors of POAF. POAF increases the morbidity; length of hospital stay and these patients show decreased survival after off-pump CABG. © 2019, Indian Association of Cardiovascular-Thoracic Surgeons.

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2019

N. M Sundaram, Amirthalingam, S., Dr. Ullas Mony, Dr. Praveen Varma, and Dr. Jayakumar Rangasamy, “Injectable Chitosan-nano Bioglass Composite Hemostatic Hydrogel for Effective Bleeding Control”, International Journal of Biological Macromolecules, vol. 129, pp. 936-943, 2019.[Abstract]


Effective bleeding control is a major concern in trauma and major surgeries. Chitosan (Ch) as hemostatic agent has been widely used and when applied at the site of injury it acts by aggregating blood cells and forming a plug. Our prime interest is to improve the blood clotting property of Ch hydrogel. Incorporation of nanobioglass (nBG) with silica (activate coagulation factor XII), calcium (activate intrinsic pathway) and phosphate (initiates extrinsic pathway) ions into Ch hydrogel (protonated NH group) would act at the same time and bring about rapid blood clot formation. Sol-gel method was followed to synthesize nBG particles and its particle size was found to be 14 ± 3 nm. 2%Ch-5%nBG hydrogel was then prepared and studied using SEM and FTIR. The prepared hydrogel was injecable and was also cytocompatible with HUVEC. In in vitro blood clotting study and in vivo major organ injury model, 2%Ch-5%nBG hydrogel formed rapid blood clot than 2%Ch hydrogel. Hence, 2%Ch-5%nBG hydrogel might have great potential to achieve effective bleeding control during critical situations.

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2019

A. Gurram, Krishna, N., Anu Vasudevan, Baquero, L. Alberto, Jayant, A., and Dr. Praveen Varma, “Female Gender is not a Risk Factor for Early Mortality after Coronary Artery Bypass Grafting.”, Ann Card Anaesth, vol. 22, no. 2, pp. 187-193, 2019.[Abstract]


<p><b>Background: </b>The female gender is considered as a risk factor for morbidity and mortality after coronary artery bypass grafting (CABG).</p>

<p><b>Aim: </b>In this analysis, we assessed the impact of female gender on early outcome after CABG.</p>

<p><b>Study Design: </b>This is a retrospective analysis of data from our center situated in South India.</p>

<p><b>Statistical Analysis: </b>Patients were categorized according to gender and potential differences in pre-operative and post-operative factors were explored. Significant risk factors were then built in a multivariate model to account for differences in predicting gender influence on surgical outcome.</p>

<p><b>Methods: </b>773 consecutive patients underwent first time CABG between January 2015 and December 2016. 96.77% of cases were performed using off-pump technique. 132 (17.07%) patients were females. These patients formed the study group.</p>

<p><b>Results: </b>The in-house/ 30-day mortality in females was similar to that of males (3.03% vs. 3.12%, p value 0.957). Mediastinitis developed more commonly in females (5.35% vs. 1.30%; p value 0.004) compared to males. There were more re-admissions to hospital for female patients (21.37% in females vs. 10.14% in males, p value &lt;0.001). In multivariate analysis using logistic regression; there was a significant association between age (OR 1.08), chronic obstructive airway disease (OR 4.315), and use of therapeutic antibiotics (OR 6.299), IABP usage (OR 11.18) and renal failure requiring dialysis (OR 28.939) with mortality.</p>

<p><b>Conclusions: </b>Early mortality in females was similar to that of males. Females were associated with higher rate of wound infection and readmission to hospital.</p>

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2019

Rajesh Jose, Shetty, A., Krishna, N., Chathoth, V., Renjitha Bhaskaran, Jayant, A., and Dr. Praveen Varma, “Early and Mid-Term Outcomes of Patients Undergoing Coronary Artery Bypass Grafting in Ischemic Cardiomyopathy.”, J Am Heart Assoc, vol. 8, no. 10, p. e010225, 2019.[Abstract]


Background Many observational studies and trials have shown that coronary artery bypass grafting improves the survival in patients with ischemic cardiomyopathy. However, these results are based on data generated from developed countries. Poor socioeconomic statuses, lack of uniformity in healthcare delivery, differences in risk profile, and affordability to access optimal health care are some factors that make the conclusions from these studies irrelevant to patients from India. Methods and Results One-hundred and sixty-two patients with severe left ventricular dysfunction (ejection fraction ≤35%) who underwent coronary artery bypass grafting from 2009 to 2017 were enrolled for this study. Mean age of the study population was 58.67±9.70&nbsp;years. Operative mortality was 11.62%. Thirty day/in-house composite outcome of stroke and perioperative myocardial infarction were 5.8%. The percentage of survival for 1&nbsp;year was 86.6%, and 5-year survival was 79.9%. Five-year event-free survival was 49.3%. The mean ejection fraction improved from 30.7±4.08% (range 18-35) to 39.9±8.3% (range 24-60). Lack of improvement of left ventricular function was a strong predictor of late mortality (hazard ratio, 21.41; CI 4.33-105.95). Even though there was a trend towards better early outcome in off-pump CABG , the 5-year survival rates were similar in off-pump and on-pump group (73.4% and 78.9%, respectively; P value 0.356). Conclusions We showed that coronary artery bypass grafting in ischemic cardiomyopathy was associated with high early composite outcomes. However, the 5-year survival rates were good. Lack of improvement of left ventricular function was a strong predictor of late mortality.

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2019

B. Kavumkal Rajagopalan, Rajesh Jose, Kader, N. Puthukudiy, and Dr. Praveen Varma, “Coarctation of aorta aneurysm with aberrant right subclavian artery and single carotid artery: Surgical and perfusion strategies.”, J Thorac Cardiovasc Surg, vol. 157, no. 1, pp. e17-e19, 2019.

2018

A. Gopinathan, Kumar, A., Sen, A. C., Sudha, S., Dr. Praveen Varma, Gs, S., Eapen, M., and Dinesh, K. R., “A Case Series and Review of Endocarditis from India.”, Open Microbiol J, vol. 12, pp. 28-33, 2018.[Abstract]


Introduction: Bacillus cereus is a gram positive bacilli found commonly in the soil and environment. It is a bacteria rarely associated with endocarditis.

Case History: Intravenous drug abuse, presence of valvular defects, pacemakers, immunodeficiency are some of the known risk factors for endocarditis. We present here a case series of two patients with endocarditis along with a review of the literature.

Conclusion: This is the first report of endocarditis from India to the best of our knowledge.

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2018

Dr. Praveen Varma, Krishna, N., Dr. Hisham Ahamed, and Madassery, S., “Posterior mitral leaflet plication for hypertrophic obstructive cardiomyopathy.”, Asian Cardiovascular and Thoracic Annals, vol. 26, no. 5, pp. 400-403, 2018.[Abstract]


Anomalies of the mitral valve apparatus in hypertrophic cardiomyopathy are an important cause of systolic anterior motion. Patients with significant residual obstruction due to systolic anterior motion after myectomy and anterior mitral leaflet plication may end up having mitral valve replacement. We describe the case of a 52-year-old man who underwent posterior mitral leaflet plication to correct residual systolic anterior motion after anterior mitral leaflet plication.

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2018

Dr. Praveen Varma and Dr. Hisham Ahamed, “Left Atrial Approach to Septal Myectomy: Word of Caution.”, Annals of Thoracic Surgery, vol. 106, no. 5, pp. 1591-1592, 2018.

2018

R. Liza Jose and Dr. Praveen Varma, “Rationale for change in the criteria for defining severe ischemic mitral regurgitation in 2017 American College of Cardiology/American heart association guidelines.”, Ann Card Anaesth, vol. 21, no. 4, pp. 464-465, 2018.

2018

S. Gangadharan, Sundaram, K. R., Vasudevan, S., Ananthakrishnan, B., Balachandran, R., Cherian, A., Dr. Praveen Varma, Gracia, L. Bakero, Murukan, K., Madaiker, A., Rajesh Jose, Seetharaman, R., Kirun Gopal, Menon, S., Thushara, M., Jose, R. Liza, Deepak, G., Vanga, S. Babu, and Jayant, A., “Predictors of acute kidney injury in patients undergoing adult cardiac surgery.”, Ann Card Anaesth, vol. 21, no. 4, pp. 448-454, 2018.[Abstract]


Background: Acute kidney injury (AKI) after cardiac surgery (CS) is not uncommon and has serious effects on mortality and morbidity. A majority of patients suffer mild forms of AKI. There is a paucity of Indian data regarding this important complication after CS.

Aims and Objectives: The primary objective was to study the incidence of AKI associated with CS in an Indian study population. Secondary objectives were to describe the risk factors associated with AKI-CS in our population and to generate outcome data in patients who suffer this complication.

Methods: Serial patients (n = 400) presenting for adult CS (emergency/elective) at a tertiary referral care hospital in South India from August 2016 to November 2017 were included as the study individuals. The incidence of AKI-CS AKI network (AKIN criteria), risk factors associated with this condition and the outcomes following AKI-CS are described.

Results: Out of 400, 37 (9.25%) patients developed AKI after CS. AKI associated with CS was associated with a mortality of 13.5% (no AKI group mortality 2.8%, P = 0.001 [P < 0.05]). When AKI was severe enough to need renal replacement therapy, the mortality increased to 75%. Patients with AKI had a mean hospital stay 16.92 ± 12.75 days which was comparatively longer than patients without AKI (14 ± 7.98 days). Recent acute coronary syndrome, postoperative atrial fibrillation, and systemic hypertension significantly predicted the onset of AKI-CS in our population.

Conclusions: The overall incidence of AKI-CS was 9.25%. The incidence of AKI-CS requiring dialysis (Stage 3 AKIN) AKI-CS was lower (2%). However, mortality risks were disproportionately high in patients with AKIN Stage 3 AKI-CS (75%). There is a need for quality improvement in the care of patients with AKI-CS in its most severe forms since mortality risks posed by the development of Stage 3 AKIN AKI is higher than reported in other index populations from high resource settings.

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2018

Dr. Praveen Varma and Krishna, N., “Transcatheter aortic valve replacement: Role of anesthesiologists.”, Ann Card Anaesth, vol. 21, no. 3, pp. 285-286, 2018.

2018

Nivedhitha Sundaram M., V. Kaliannagounder, K., Selvaprithiviraj, V., Suresh, M., Biswas, R., Vasudevan, A. K., Dr. Praveen Varma, and Dr. Jayakumar Rangasamy, “Bioadhesive, Hemostatic, and Antibacterial in Situ Chitin-Fibrin Nanocomposite Gel for Controlling Bleeding and Preventing Infections at Mediastinum”, ACS Sustainable Chemistry and Engineering, vol. 6, pp. 7826-7840, 2018.[Abstract]


Mediastinitis occurs after cardiac surgery and is a major threat to patient's life due to postoperative bleeding and deep sternal wound infection. Major challenge in treating this condition is that it demands a material that should adhere to the applied site and act as both a hemostatic and an antibacterial agent. On the basis of this we have developed an in situ forming tissue adhesive chitin-fibrin (CH-FB) gel with tigecycline loaded gelatin nanoparticles (tGNPs) for controlling bleeding and preventing bacterial infection. Spherical shaped tGNPs (231 ± 20 nm) were prepared and characterized. In situ forming tGNPsCH-FB gel was formed using a dual syringe applicator in which one syringe was loaded with a mixer of fibrinogen solution, chitin gel, and tGNPs; the other syringe was loaded with a mixture of thrombin solution, chitin gel, and tGNPs. Both these mixtures were injected together. In situ gel formed within a minute and exhibited excellent tissue adhesive property. tGNPsCH-FB gel was found to be cyto-compatible against human umbilical vein endothelial cells (HUVECs). Sustained release of tigecycline from tGNPsCH-FB gel was found to occur over 21 days. In vitro antibacterial activity of tGNPsCH-FB gel was tested against Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli (E. coli), and their clinical isolates. Furthermore, in vivo hemostatic potential of tGNPsCH-FB gel was evaluated in deep organ injuries created in Sprague-Dawley rats. The developed gel exhibited rapid blood clotting potential by achieving hemostasis within 154 and 84 s under femoral artery (pressured) and liver (oozing) bleeding conditions. Hence, these findings exhibit the potential application of the developed tGNPsCH-FB gel to adhere at surgical site for controlling bleeding and prevent bacterial infection after cardiac surgery. © 2018 American Chemical Society.

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2018

J. Joseph, Krishnan, A. G., Cherian, A. M., Rajagopalan, B., Jose, R., Dr. Praveen Varma, Maniyal, V., Balakrishnan, S., Shantikumar V Nair, and Dr. Deepthy Menon, “Transforming Nanofibers into Woven Nanotextiles for Vascular Application”, ACS Applied Materials and Interfaces, vol. 10, pp. 19449-19458, 2018.[Abstract]


This study investigates the unique properties, fabrication technique, and vascular applications of woven nanotextiles made from low-strength nanoyarns, which are bundles of thousands of nanofibers. An innovative robotic system was developed to meticulously interweave nanoyarns in longitudinal and transverse directions, resulting in a flexible, but strong woven product. This is the only technique for producing seamless nanotextiles in tubular form from nanofibers. The porosity and the mechanical properties of nanotextiles could be substantially tuned by altering the number of nanoyarns per unit area. Investigations of the physical and biological properties of the woven nanotextile revealed remarkable and fundamental differences from its nonwoven nanofibrous form and conventional textiles. This enhancement in the material property was attributed to the multitude of hierarchically arranged nanofibers in the woven nanotextiles. This patterned woven nanotextile architecture leads to a superhydrophilic behavior in an otherwise hydrophobic material, which in turn contributed to enhanced protein adsorption and consequent cell attachment and spreading. Short-term in vivo testing was performed, which proved that the nanotextile conduit was robust, suturable, kink proof, and nonthrombogenic and could act as an efficient embolizer when deployed into an artery. © 2018 American Chemical Society.

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2017

Dr. Praveen Varma, Krishna, N., Jose, R. Liza, and Madkaiker, A. Narayan, “Ischemic mitral regurgitation.”, Ann Card Anaesth, vol. 20, no. 4, pp. 432-439, 2017.[Abstract]


<p>Ischemic mitral regurgitation (IMR) is a frequent complication of left ventricular (LV) global or regional pathological remodeling due to chronic coronary artery disease. It is not a valve disease but represents the valvular consequences of increased tethering forces and reduced closing forces. IMR is defined as mitral regurgitation caused by chronic changes of LV structure and function due to ischemic heart disease and it worsens the prognosis. In this review, we discuss on etiology, pathophysiology, and mechanisms of IMR, its classification, evaluation, and therapeutic corrective methods of IMR.</p>

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2016

Rajesh Jose, Dr. Praveen Varma, and Agarwal, G., “Prosthetic heart valve thrombosis in pregnancy”, Kerala Heart Journal, vol. 6, no. 2, 2016.[Abstract]


Effective anticoagulation is critical in patients with prosthetic heart valve [PHV], but remains challenging in pregnancy because both oral anticoagulation and heparin are associated with important fetal and maternal risks. Herein we report a case of 23-year-old pregnant woman presented with PHV thrombosis during late second trimester and complicated by Immune mediated thrombocytopenia.She underwent Redo MVR [25mm CE Perimount Plus Pericardial Bioprosthetic valve] + LSCS. Peri operatively she was managed with Platelet transfusions/ Immunoglobulins/ Steroid pulse therapy and recovered well.

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2016

A. Madkaiker, Krishna, N., Kumaraswamy, N., and Dr. Praveen Varma, “Infected pseudoaneurysm of the left anterior descending artery.”, BMJ Case Rep, vol. 2016, 2016.[Abstract]


<p>Primary percutaneous transluminal coronary angioplasty (PTCA) with the insertion of a stent is a well-established procedure for management of coronary artery disease. Infected pseudoaneurysms following PTCA and stenting are very rare and have poor outcomes if not managed properly. We are presenting a case of a man aged 50 years with infected pseudoaneurysm of the left anterior descending artery following multiple percutaneous interventions for coronary artery disease. In this paper, we have described the presentation, diagnosis and management of this patient and have discussed the aetiology and management options of infected pseudoaneurysm affecting coronary arteries.</p>

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2016

A. N. Madkaiker, Krishna, N., Rajesh Jose, Balasubramoniam, K. R., Murukan, P., Baquero, L., and Dr. Praveen Varma, “Superior Vena Cava Syndrome Caused by Pacemaker Leads.”, Ann Thorac Surg, vol. 101, no. 6, pp. 2358-61, 2016.[Abstract]


<p>Superior vena cava syndrome is one of the rare adverse events associated with pacemaker leads. We describe a 47-year-old woman with a pacemaker implanted 10 years earlier who presented to us with superior vena cava syndrome managed surgically. We report the presentation, diagnosis, and treatment of this patient and the causes and management options of superior vena cava obstruction associated with pacemaker leads. </p>

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2015

M. Idhrees Abdulsamath, Pillai, V., Radhakrishnan, B., Paniker, V., Dr. Praveen Varma, and Karunakaran, J., “A case of rheumatic mitral stenosis with subaortic ventricular septal defect and anomalous right coronary artery from left sinus”, Indian Journal of Thoracic and Cardiovascular Surgery volume, vol. 31, no. 2, pp. 184 - 186, 2015.[Abstract]


Rheumatic mitral stenosis (MS) is common in India. Ventricular septal defect (VSD) is the commonest congenital heart disease seen clinically. The incidence of right coronary artery (RCA) arising from the left aortic sinus is 0.17 %. The presence of all the three lesions in a patient is likely to be extremely rare. We present a patient who had all the three lesions, and to the best of our knowledge, this is the first such case to be reported.

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2015

Dr. Praveen Varma, Namboodiri, N., Raman, S. Puthuvasse, Pappu, U. Koraparamb, Gadhinglajkar, S. Vitthal, Ho, J., Owais, K., and Mahmood, F., “CASE 10–2015: Cardiac Resynchronization Therapy: Role of Intraoperative Real-Time Three-Dimensional Transesophageal Echocardiography”, Journal of Cardiothoracic and Vascular Anesthesia, vol. 29, no. 5, pp. 1365 - 1375, 2015.[Abstract]


SIGNIFICANT VENTRICULAR DYSSYNCHRONY manifested by left bundle-branch block (LBBB) and wide QRS complex is demonstrated on an electrocardiogram (ECG) in 30% of patients with heart failure. 1 Left ventricular (LV) dyssynchrony causes decreased ventricular filling and impaired LV contractility and is associated with increased mortality. 2 In the past decade, cardiac resynchronization therapy (CRT), achieved by simultaneous LV and right ventricular (RV) pacing, has emerged as a potent therapeutic option that improves the quality of life and functional status of patients with congestive heart failure, as well as prolongs survival. 3 , 4 The goal of CRT is pacing the left ventricle at the latest activation site so that the left ventricle contracts in a synchronized manner, allowing ventricular ejection to occur before relaxation of the septum; this decreases mitral valve regurgitation (MR), increases the stroke volume, and decreases end-diastolic volume (EDV). By resynchronizing atrioventricular contraction, normal mitral valve timing is restored, and MR is reduced or eliminated. 5 In the Multicenter In Sync Randomized Clinical Evaluation (MIRACLE) trial, CRT was associated with reverse remodeling, reduced EDV, reduced end-systolic volume (ESV), reduced LV mass, increased ejection fraction (EF), reduced MR, and improved myocardial performance index. 6

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2015

Krishna, Anirudh Nair, and Dr. Praveen Varma, “Risk Stratification in Cardiac Surgery”, Indian Journal of Thoracic and Cardiovascular Surgery, 2015.

2015

Dr. Praveen Varma, Raman, S. P., Neema, P. K., and Shekar, P. S., “Hypertrophic cardiomyopathy”, Indian Journal of Thoracic and Cardiovascular Surgery, vol. 31, pp. 153-161, 2015.[Abstract]


Hypertrophic cardiomyopathy is a common genetic cardiovascular disease affecting the general population with an estimated prevalence of 1 in 500 with autosomal dominant pattern of inheritance and is an important cause of intractable heart failure. Up to 70 % of patients present with left ventricular outflow tract obstruction due to asymmetric hypertrophy of the interventricular septum and systolic anterior motion of anterior mitral leaflet. These patients are initially managed with medical treatment. Persistent symptoms (dyspnea and chest pain NYHA class 3 or 4 and syncope) in spite of optimal medical therapy and presence of gradients above 50 mm of Hg at rest or by provocation are usually referred for invasive strategy. Extended surgical myectomy and alcohol septal ablation are current strategies employed for relief of left ventricular outflow tract gradients. There is a higher incidence of residual gradients, more incidences of conduction blocks requiring pacemaker implantation and more risk of life-threatening arrhythmias with alcohol ablation compared to surgery and hence is currently recommended as a treatment option only in elderly patients with poor risk profile for surgery. Early and long-term results after surgery are excellent, making it as the gold standard for management of hypertrophic cardiomyopathy. © 2015, Indian Association of Cardiovascular-Thoracic Surgeons.

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2015

Dr. Praveen Varma, “Risk Assessment Scores in Cardiac Surgery”, Annals of Cardiac Anaesthesia, vol. 18, pp. 170-171, 2015.

2014

B. L. Robinson, Kwong, R. Y., Dr. Praveen Varma, Wolfe, M., and Couper, G., “Magnetic resonance imaging of complex partial anomalous pulmonary venous return in adults.”, Circulation, vol. 129, no. 1, pp. e1-2, 2014.[Abstract]


Adults with congenital cardiac abnormalities surpass the number of children because of better assessment of cardiac anatomy and function, monitoring, operative options, patient outcomes, and increased survival into adulthood.1 Partial anomalous pulmonary venous return may present in adulthood, particularly if asymptomatic with small shunt fraction. One or more pulmonary veins, most commonly an anomalous right upper pulmonary vein, connect to a systemic vein or the right atrium; this accounts for 0.5% of congenital cardiac defects. Cardiovascular imaging continues to evolve rapidly for accurate preoperative evaluation and operative planning.

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2014

P. Bayya, Dr. Praveen Varma, Raman, S., and Neema, P., “Emergency mitral valve replacement for acute severe mitral regurgitation following balloon mitral valvotomy: Pathophysiology of hemodynamic collapse and peri-operative management issues”, Annals of Cardiac Anaesthesia, vol. 17, no. 1, p. 52, 2014.[Abstract]


Severe mitral regurgitation (MR) following balloon mitral valvotomy (BMV) needing emergent mitral valve replacement is a rare complication. The unrelieved mitral stenosis is compounded by severe MR leading to acute rise in pulmonary hypertension and right ventricular afterload, decreased coronary perfusion, ischemia and right ventricular failure. Associated septal shift and falling left ventricular preload leads to a vicious cycle of myocardial ischemia and hemodynamic collapse and needs to be addressed emergently before the onset of end organ damage. In this report, we describe the pathophysiology of hemodynamic collapse and peri-operative management issues in a case of mitral valve replacement for acute severe MR following BMV.

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2014

Dr. Praveen Varma and Neema, P., “Hypertrophic cardiomyopathy: Part 1 - Introduction, pathology and pathophysiology”, Annals of Cardiac Anaesthesia, vol. 17, no. 2, pp. 118-124, 2014.[Abstract]


Hypertrophic cardiomyopathy (HCM) is the most common genetic cardiovascular disease with many genotype and phenotype variations. Earlier terminologies, hypertrophic obstructive cardiomyopathy and idiopathic hypertrophic sub-aortic stenosis are no longer used to describe this entity. Patients present with or without left ventricular outflow tract (LVOT) obstruction. Resting or provocative LVOT obstruction occurs in 70% of patients and is the most common cause of heart failure. The pathology and pathophysiology of HCM includes hypertrophy of the left ventricle with or without right ventricular hypertrophy, systolic anterior motion of mitral valve, dynamic and mechanical LVOT obstruction, mitral regurgitation, diastolic dysfunction, myocardial ischemia, and fibrosis. Thorough understanding of pathology and pathophysiology is important for anesthetic and surgical management.

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2014

S. Kundan, Dr. Praveen Varma, and Koshy, T., “Real-time three-dimensional transoesophageal echocardiography for diagnosing the extent of dehiscence of Starr-Edward valve prosthesis in the mitral position.”, Eur Heart J Cardiovasc Imaging, vol. 15, no. 9, p. 1060, 2014.[Abstract]


A 55-year-old male underwent mitral and aortic valve replacement in the year 2005. He developed prosthetic valve infective endocarditis and underwent a re-double valve replacement with in a period of 45 days. The patient was re-admitted with pulmonary oedema in the year 2013. Transthoracic echocardiogram showed severe paravalvular mitral regurgitation (MR) and fluoroscopy showed a rocking movement of the Starr–Edward valve (Panels A and B, and Supplementary data online, Video S1). Intraoperative transoesophageal echocardiography (TEE) imaged in the three standard mid-oesophageal ventricular views: four-chamber (Panel C and Supplementary data online, Video S2 showing dehiscence in both 2 and 8 o'clock), two-chamber (Panels D and E, and Supplementary data online, Video S3 showing dehiscence at 4 o'clock) and long-axis (LAX) (Panel F and Supplementary data online, Video S4 demonstrating significant paravalvular space at 6 o'clock). From these views, it was evident that the prosthetic valve had a dehiscence of ∼50% of its circumference. The real-time three-dimensional (3D) TEE with zoom (iE33 x-MATRIX echo system; Philips Medical System, MA, USA) showed the full extent of prosthetic valve dehiscence. Only remaining attachment was at the level of aortic root (Panels G and H, and Supplementary data online, Video S5). The findings were confirmed at surgery (Panel I). Two-dimensional (2D) TEE uses sequential images to identify the location and extent of paravalvular MR by superimposing the face of a clock on the valve. The aortic valve is defined at the 12 o'clock position and the left atrial appendage lies in the 10 o'clock position. However, 2D TEE underestimated the severity of dehiscence and 3D TEE showed superior imaging quality for the assessment of severity of the dehiscence.

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2014

Dr. Praveen Varma, Raman, S. Puthuvasse, and Neema, P. Kumar, “Hypertrophic cardiomyopathy part II--anesthetic and surgical considerations.”, Ann Card Anaesth, vol. 17, no. 3, pp. 211-21, 2014.[Abstract]


Hypertrophic cardiomyopathy (HCM) poses many unique challenges regarding the conduct of anesthesia and surgery. Adequate preload, control of sympathetic stimulation, heart rate, and increased afterload are required to decrease the left ventricular outflow tract obstruction. Comprehensive intraoperative transesophageal echocardiography (TEE) examination confirms the diagnosis, elucidates the pathophysiology, and identifies the various anomalies of mitral valve apparatus and allows assessment of the adequacy of surgery. In this review, we focus on the preoperative assessment, conduct of anesthesia and comprehensive TEE examination of patients presenting for surgery with HCM. The various surgical options are extended myectomy and resection, plication and release.

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2014

Dr. Praveen Varma, N, N., SP, R., KP, U., and SV, G., “Intra-Operative Three Dimensional Transesophageal Echocardiography Guided Left Resynchronization Therapy”, J Cardiothorac Vasc Anesthesia, 2014.

2014

Dr. Praveen Varma, Raman, S. Puthuvasse, Unnikrishnan, K. Pappu, Kundan, S., and Gadhinglajkar, S. Vitthal, “Intraoperative transesophageal echocardiography diagnosis of concomitant hypertrophic cardiomyopathy with anomalous insertion of a papillary muscle band to the interventricular septum in a patient for aortic valve replacement.”, J Cardiothorac Vasc Anesth, vol. 28, no. 6, pp. e56-58, 2014.[Abstract]


A 53-year-old man was admitted for surgery with a diagnosis of aortic valve stenosis, left ventricular outflow tract (LVOT) obstruction by systolic anterior motion of the mitral valve, and moderate-to-severe mitral regurgitation. Peak and mean LVOT gradients measured by transthoracic echocardiography were 91 mmHg and 51 mmHg, respectively. Intraoperative transesophageal echocardiography (TEE) showed calcific aortic stenosis with moderate aortic insufficiency and systolic anterior motion of the anterior leaflet of the mitral valve. The interventricular septum measured 2.86 cm in diastole, with anomalous insertion of a band from the anterolateral papillary muscle to the basal septum. Peak LVOT gradient was 208 mmHg in concurrence with moderate-to-severe mitral regurgitation (Fig 1, Video clip 1). The aortic valve was bicuspid and calcified. He underwent aortic valve replacement with a mechanical prosthesis, extended septal myectomy, and excision of an abnormal band to the ventricular septum. The anterolateral papillary muscle was bifid, with 1 head giving rise to the chordae and the other continued as a band to insert into the anterobasal septum. Postoperative TEE showed no LVOT obstruction, mild mitral regurgitation, and a mean gradient of 14 mmHg across the aortic valve prosthesis.

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2014

Dr. Praveen Varma, Kundan, S., Ananthanarayanan, C., Panicker, V. Thomas, Pillai, V. Velayudhan, Sarma, P. Sankara, and Karunakaran, J., “Demographic profile, clinical characteristics and outcomes of patients undergoing coronary artery bypass grafting—retrospective analysis of 4,024 patients”, Indian J Thorac Cardiovasc Surg, vol. 30, no. 4, pp. 272 - 277, 2014.[Abstract]


Large databases give an insight into patient characteristics and outcomes of patients undergoing coronary artery bypass grafting (CABG) in western populations. However, there is paucity of data in Indian population. This study was designed to understand the clinical characteristics and short-term outcomes of patients undergoing CABG at our institute.

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2014

B. K. Radhakrishnan, A., M. Idhrees, Devarajan, S., Panicker, V. T., Pillai, V. V., Dr. Praveen Varma, and Karunakaran, J., “Primary Modified Bentall's Procedure in a Case of Laubry-Pezzi Syndrome”, The Annals of Thoracic SurgeryThe Annals of Thoracic Surgery, vol. 98, no. 4, pp. 1445 - 1447, 2014.[Abstract]


Modified Bentall's procedure done as part of the primary repair in Laubry-Pezzi syndrome is very rarely described in the literature. We present a case of a 33-year-old man with a subpulmonic venticular septal defect, aneurysmal dilatation of the aortic root and ascending aorta, with an associated patent ductus arteriosus, corrected by the incorporation of Yacoub's techique for ventricular septal defect closure with a modified Bentall's procedure and transpulmonary patent ductus arteriosus ligation. The postoperative course was unremarkable. Early follow-up reports show good biventricular function without residual ventricular septal defect or iatrogenic ventricular outflow tract obstructions.Modified Bentall's procedure done as part of the primary repair in Laubry-Pezzi syndrome is very rarely described in the literature. We present a case of a 33-year-old man with a subpulmonic venticular septal defect, aneurysmal dilatation of the aortic root and ascending aorta, with an associated patent ductus arteriosus, corrected by the incorporation of Yacoub's techique for ventricular septal defect closure with a modified Bentall's procedure and transpulmonary patent ductus arteriosus ligation. The postoperative course was unremarkable. Early follow-up reports show good biventricular function without residual ventricular septal defect or iatrogenic ventricular outflow tract obstructions.

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2013

Dr. Praveen Varma, “A small step in the right direction.”, Ann Card Anaesth, vol. 16, no. 3, pp. 167-8, 2013.[Abstract]


Risk models are used for two main reasons. Firstly, a risk model allows the calculation of the risk of mortality and morbidity of a surgical procedure. This is important as it serves to guide the clinician and the patient about the advisability of an operation by helping to weigh the risk against the benefits. Secondly, a risk model is a method of quality control. Risk-adjusted mortality rate can be used as a measure of the quality of the performance of the hospital, unit, or surgeon. Risk models try to predict the outcome based on preoperative risk factors or variables. There are several such models available; however, The Society of Thoracic Surgeons' (STS) risk score and the EuroSCORE are the widely used models for risk assessment.

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2013

S. Gadhinglajkar, Sreedhar, R., Dr. Praveen Varma, and Pal, S., “Plasma Exchange Transfusion for Management of Altered Heparin Responsiveness Before Cardiopulmonary Bypass”, Journal of Cardiothoracic and Vascular AnesthesiaJournal of Cardiothoracic and Vascular Anesthesia, vol. 27, no. 5, pp. e58 - e60, 2013.[Abstract]


We report a case of altered heparin responsiveness encountered before establishment of cardiopulmonary bypass (CPB) in a patient with valvular heart disease and cardiac failure. She was treated with plasma exchange transfusion (PET) in order to achieve an acceptable activated coagulation time (ACT) before institution of CPB.

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2013

Dr. Praveen Varma and MU, M., “False diagnosis of acute Type A dissection”, Ann Cardiac Anaesth, vol. 16, no. 3, p. 225, 2013.

2013

V. GJ and Dr. Praveen Varma, “Giant left atrial myxoma causing mitral inflow and pulmonary venous obstruction”, IJPTM , vol. 1, p. 32, 2013.

2012

S. Misra, Dash, P. Kumar, Koshy, T., Dr. Praveen Varma, Pal, S., Dineshkumar, U. Shanmukhas, Banayan, J., and Capdeville, M., “CASE 5--2012: incidentally detected patent foramen ovale in a patient undergoing aortic valve replacement: to close or not to close?”, J Cardiothorac Vasc Anesth, vol. 26, no. 4, pp. 721-728, 2012.[Abstract]


With the increased use of routine intraoperative transesophageal echocardiography (TEE), cardiac anesthesiologists often discover a patent foramen ovale (PFO) in the operating room. Whether or not to repair the defect surgically is a difficult question to answer because this may involve altering surgical management (eg, converting from an off-pump technique to on-pump technique) and, thus, perhaps increasing surgical risk. Furthermore, noninvasive techniques (percutaneous closure in the catheterization suite) are available for closure as well. Lastly, depending on the physiologic effects and/or symptomatology, closure may not even be indicated clinically. This complex scenario is further complicated by the fact that the patient is unable to contemplate the risks and benefits of available options because he/she is under general anesthesia.

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2010

P. Kumar Sinha, Kumar, B., and Dr. Praveen Varma, “Anesthetic management for surgical repair of Ebstein's anomaly along with coexistent Wolff-Parkinson-White syndrome in a patient with severe mitral stenosis.”, Ann Card Anaesth, vol. 13, no. 2, pp. 154-8, 2010.[Abstract]


Ebstein's anomaly (EA) is the most common cause of congenital tricuspid regurgitation. The associated anomalies commonly seen are atrial septal defect or patent foramen ovale and accessory conduction pathways. Its association with coexisting mitral stenosis (MS) has uncommonly been described. The hemodynamic consequences and anesthetic implications, of a combination of EA and rheumatic MS, have not so far been discussed in the literature. We report successful anesthetic management of a repair of EA and mitral valve replacement in a patient with coexisting Wolff-Parkinson-White (WPW) syndrome.

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2009

H. L. Lazar, Dr. Praveen Varma, Shapira, O. M., Soto, J., and Shaw, P., “Endograft collapse after thoracic stent-graft repair for traumatic rupture”, Ann Thorac Surg . , vol. 87, no. 5, pp. 1582-1583, 2009.[Abstract]


Endovascular stent grafting has emerged as a new strategy for repair of traumatic aortic disruptions; however, this technique is not without complications. In this report, we describe a case of endograft collapse after a traumatic aortic rupture.

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2008

P. Sinha, Dr. Praveen Varma, Korach, A., and Shapira, O. M., “Transmitral endocavitary repair of inferior left ventricular pseudoaneurysm: A simplified approach in patients requiring concomitant mitral valve surgery”, The Journal of thoracic and cardiovascular surgery, vol. 135, no. 6, pp. 1382–1383, 2008.[Abstract]


Left ventricular pseudoaneurysms (LVPAs) arise from contained myocardial rupture after acute myocardial infarction. Their propensity to rapid enlargement and rupture mandates expeditious surgical management.1 We report a case of LVPA repair through an endocavitary transmitral approach in a patient undergoing concomitant mitral valve surgery.

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2008

P. Kumar Neema, Dr. Praveen Varma, Manikandan, S., and Rathod, R. Chandra, “Perioperative issues due to long-standing lung collapse during repair of a large ascending aortic aneurysm.”, Ann Card Anaesth, vol. 11, no. 2, pp. 119-22, 2008.[Abstract]


Acute lung collapse during open-heart surgery may potentially lead to problems such as inadequate gas exchange, increased pulmonary vascular resistance, increased afterload to the right ventricle, and difficulty in weaning from cardiopulmonary bypass (CPB). Therefore, expansion of the lungs is ensured prior to separation from CPB. We report the inability to manually expand a chronically collapsed lung during the repair of ascending aortic aneurysm. The collapsed lung did not pose difficulty in separation from CPB and in blood gas management during the perioperative period. We discuss perioperative management issues in such situations.

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2007

P. K. Neema, Manikandan, S., Rathod, R. C., and Dr. Praveen Varma, “Fatal endotracheal haemorrhage in a patient undergoing repair of a large ascending aortic aneurysm.”, European Journal of Anaesthesiology, vol. 24, no. 7, pp. 646-7, 2007.

2007

P. Kumar Neema, Pathak, S., Dr. Praveen Varma, Manikandan, S., Rathod, R. Chandra, Tempe, D. K., and Tung, A., “Case 2—2007 Systemic Air Embolization After Termination of Cardiopulmonary Bypass”, Journal of cardiothoracic and vascular anesthesia, vol. 21, no. 2, pp. 288–297, 2007.

2006

J. G. Akbari, Dr. Praveen Varma, Gadhinglajkar, S. V., and Neelakandhan, K. S., “Late Entrapment of Ball and Cage Valve in Mitral Position”, Asian Cardiovascular and Thoracic Annals, vol. 14, no. 1, pp. e1-e3, 2006.[Abstract]


A 32-year-old female underwent mitral valve replacement with total chordal preservation (Miki's technique) using 26mm (1M) Starr-Edward prosthesis (SEP) in 1988. The patient was in NYHA class-I until 2001. She progressed to NYHA class-III with paroxysmal nocturnal dyspnoea. Transthoracic echocardiogram showed increased prosthetic valve gradient, and cardiac catheterization confirmed the findings. Intraoperatively, the poppet movement in the cage was found to be restricted due to the preserved subvalvular apparatus entrapping the poppet inside the prosthetic valve cage.

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2006

Dr. Praveen Varma and Neema, P. Kumar, “Post percutaneous transmitral commissurotomy mitral regurgitation; Underestimated Subvalvar Disease. Reply to editor”, J Thorac Cardio Vasc Surg, vol. 131, no. 4, pp. 927-928, 2006.[Abstract]


We thank Choudhary and his colleagues for their interest in our article. 1 Experience in our center and also reported by others 2 shows that the majority of patients with severe subvalvular disease achieve a satisfactory outcome with percutaneous transmitral commissurotomy (PTMC). Hence we believe that we have to look beyond the role of undiagnosed subvalvular disease as the sole mechanism in producing mitral regurgitation (MR) after PTMC. This allows us to further clarify our hypothesis.

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2006

Dr. Praveen Varma, Padmakumar, R., Harikrishnan, S., Koshy, T., and Neelakandhan, K. S., “Holt-Oram Syndrome with Hemiazygous Continuation of Inferior Vena Cava”, Asian Cardiovascular and Thoracic Annals, vol. 14, pp. 161-163, 2006.[Abstract]


A rare and previously unreported combination of Holt-Oram syndrome, atrial septal defect, patent ductus arteriosus, isolated left atrial isomerism and inferior vena caval interruption with hemiazygous continuation to the left superior vena cava is described.

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2006

P. Kumar Sinha, Neema, P. Kumar, Unnikrishnan, K. Pappu, Dr. Praveen Varma, Jaykumar, K., and Rathod, R. Chandra, “Effect of lung ventilation with 50% oxygen in air or nitrous oxide versus 100% oxygen on oxygenation index after cardiopulmonary bypass.”, J Cardiothorac Vasc Anesth, vol. 20, no. 2, pp. 136-142, 2006.[Abstract]


OBJECTIVE: This study was designed to assess the use of 100% oxygen or 50% oxygen in air or nitrous oxide after cardiopulmonary bypass (CPB) on atelectasis, as evidenced by the oxygenation index (PaO2/F(I)O2), after coronary artery bypass graft (CABG) surgery.

DESIGN: Prospective, randomized clinical study.

SETTING: University teaching hospital.

PARTICIPANT: Thirty-six adult patients undergoing CABG surgery.

INTERVENTIONS: Patients either received 50% O2 in air (50% O2 group), 50% O2 in N2O (50% N2O group), or 100% O2 (100% O2 group) after CPB.

MEASUREMENTS AND MAIN RESULTS: Apart from demographic and perioperative clinical data, extubation time, mediastinal drainage, and pulmonary complications were also recorded. After CPB, arterial blood gases done at various time points until 3 hours postextubation and oxygenation index were calculated. No significant differences were noted in demographic and perioperative data except preoperative hemoglobin and fluid use. Significant deterioration in arterial oxygenation was noted in the 100% O2 group from the baseline value, whereas significant improvement was seen in the 50% O2 group at 4 time points from baseline value and at all time points from the 100% O2 group. After initial deterioration in oxygenation, no further change was evident in the 50% N2O group. Furthermore, there was a greater increase in the oxygenation index as compared with the 100% O2 group. Time to extubation was also longer in the 100% O2 group than the 50% O2 group.

CONCLUSION: Significant deterioration in arterial oxygenation and an increase in the extubation time occurred with the use of 100% O2 after CPB, whereas better oxygenation was evident with the use of 50% O2 in air.

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2006

Dr. Praveen Varma and Neelakandhan, K. S., “Syphilitic aneurysm eroding the chest wall.”, Asian Cardiovasc Thorac Ann, vol. 14, no. 4, p. 351, 2006.

2006

P. Kumar Neema, Dr. Praveen Varma, Sinha, P. Kumar, Rathod, R. Chandra, Mahmood, F., Park, K. W., and Shernan, S., “Case 4--2006: Coexistent hypertrophic obstructive cardiomyopathy, mitral stenosis, and coronary artery fistula. (Case Conference)”, J Cardiothorac Vasc Anesth, vol. 20, no. 4, pp. 594-605, 2006.

2005

Dr. Praveen Varma, Vallath, G., Neema, P. Kumar, Sinha, P. Kumar, Sivadasanpillai, H., Menon, M. Unnikrishn, and Neelakandhan, K. Sankaran, “Clinical profile of post-operative ductal aneurysm and usefulness of sternotomy and circulatory arrest for its repair”, European journal of cardio-thoracic surgery, vol. 27, no. 3, pp. 416–419, 2005.[Abstract]


Objective: Post-operative ductal aneurysm is a rare but fatal condition. We retrospectively analyzed the clinical profile of post-operative ductal aneurysm and outcome of their repair with different surgical approaches. Methods: From January 1976 to December 2002, 13 patients underwent repair of post-operative ductal aneurysm. The case data of the patients operated were analyzed and survivors were followed-up. Three patients underwent repair through left thoracotomy, femoro-femoral bypass and 10 patients underwent patch aortoplasty through sternotomy using total circulatory arrest with minimal dissection. Among the sternotomy group, nine patients had midline sternotomy and one patient had transverse sternotomy with the patient in semi-right-lateral position. Hemoptysis (69%) was the commonest presenting symptom. Ten patients had ligation and three patients had division of ductus. Mean age at ductus interruption was 13.7±8.2 years; mean time interval for development of aneurysm was 3.6±4.2 years; mean age at aneurysm surgery was 16.9±8.8 years. Residual left to right shunt was detected in 6 (46%) patients. Results: Three patients repaired through left thoracotomy with femoro-femoral bypass died during surgery due to rupture of aneurysm during dissection and profuse bleeding. Thirty-day survival in patients operated through sternotomy using circulatory arrest was 90% (9/10). Two patients required additional incision in second left intercostal space along with midline sternotomy, for access to descending thoracic aorta. Of these two patients, one patient had bleeding from friable aorta and died; another patient developed left hemiplegia; circulatory arrest time was prolonged in this patient. Mean follow-up period was 9.6±5.3 years. Persistent left vocal cord palsy was seen in one patient. One patient was lost to follow-up after 3-years. Remaining eight patients were asymptomatic at follow-up. Conclusion: Repair of postoperative ductal aneurysm through left thoracotomy is difficult due to extreme fragility of aneurysm and because of reoperative difficulties. The immediate and long-term outcome of the cases operated through sternotomy using total circulatory arrest with minimal dissection is good. Midline sternotomy limits approach to descending thoracic aorta that can be circumvented by using transverse sternotomy with semi-right-lateral positioning of the patient.

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2005

S. Theodore, Dr. Praveen Varma, Neema, P. Kumar, and Neelakandhan, K. Sankaran, “Late aneurysm formation with destruction of the left lung after subclavian flap angioplasty for coarctation of aorta.”, J Thorac Cardiovasc Surg, vol. 129, no. 2, pp. 468-9, 2005.

2005

S. Kumar Dora, Dr. Praveen Varma, Parija, C., Nair, K., Sreedhar, R., Neelakandhan, K. Sankaran, and Tharakan, J., “Polymorphic ventricular tachycardia after radiofrequency maze procedure: report of two cases.”, J Thorac Cardiovasc Surg, vol. 129, no. 2, pp. 446-7, 2005.

2005

P. Kumar Neema, Sinha, P. Kumar, Dr. Praveen Varma, and Rathod, R. Chandra, “Vocal cord dysfunction in two patients after mitral valve replacement: consequences and mechanism.”, J Cardiothorac Vasc Anesth, vol. 19, no. 1, pp. 83-5, 2005.

2005

M. Krishna, Theodore, S., Dr. Praveen Varma, and Neelakandhan, K. S., “Spontaneous iliac arteriovenous fistula: recognition and management”, Journal of Cardiovascular Surgery (Torino), vol. 46, no. 2, p. 181, 2005.

2005

J. Gopal Akbari, Dr. Praveen Varma, Neema, P. Kumar, Menon, M. Unnikrishn, and Neelakandhan, K. Sankaran, “Clinical Profile and Surgical Outcome for Pulmonary Aspergilloma: A Single Center Experience”, The Annals of Thoracic SurgeryThe Annals of Thoracic Surgery, vol. 80, no. 3, pp. 1067 - 1072, 2005.[Abstract]


BackgroundThis retrospective study was designed to study the clinical profile, indications, postoperative complications and long-term outcome of pulmonary aspergilloma operated in our institute.BackgroundThis retrospective study was designed to study the clinical profile, indications, postoperative complications and long-term outcome of pulmonary aspergilloma operated in our institute.

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2005

Dr. Praveen Varma, Theodore, S., Neema, P. Kumar, Ramachandran, P., Sivadasanpillai, H., Nair, K. Kumar, and Neelakandhan, K. Sankaran, “Emergency surgery after percutaneous transmitral commissurotomy: Operative versus echocardiographic findings, mechanisms of complications, and outcomes”, The Journal of Thoracic and Cardiovascular Surgery, vol. 130, no. 3, pp. 772 - 776, 2005.[Abstract]


Objective This study was undertaken to determine the clinical profile of patients undergoing emergency surgery after balloon mitral valvotomy, to note operative findings and compare them with those of transthoracic echocardiography, to describe the mechanisms of complications, and to describe outcomes. Methods A retrospective study was undertaken of patients requiring emergency surgery after percutaneous mitral valvotomy with an Inoue balloon from January 1990 to December 2003. The data analyzed included demographic variables, causes and clinical presentations of complications, and outcome. In 14 consecutive cases of mitral regurgitation, an observational study comparing the operative findings with echocardiography was also undertaken. Results In 1388 cases of valvotomy, complications necessitating urgent surgery occurred in 31 cases (2.2%). Acute mitral regurgitation occurred in 23 cases (74.2 %), and cardiac tamponade occurred in 8 cases (25.8%). Mitral regurgitation was due to leaflet tearing in all cases: anterior leaflet in 20 cases and posterior leaflet in 3 cases. Hypotension, orthopnea, and pulmonary edema were the clinical presentation for mitral regurgitation. Transthoracic echocardiography underestimated the severity of mitral valve pathology. Bilateral severe commissural fusion and pliable leaflet with paracommissural calcium was seen in anterior leaflet tearing. Cardiac tamponade with hemodynamic compromise occurred as a result of left atrial perforation in 6 cases, right atrial perforation in 1 case, and left ventricular perforation in 1 case. High septal puncture led to atrial perforation. Operative mortality was 9.6%, and low cardiac output developed in 29%. Conclusion Acute mitral regurgitation and cardiac tamponade were the causes of emergency surgery after balloon valvotomy. Transthoracic echocardiography underestimated the severity of valve pathology.

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2005

P. Kumar Neema, Tambe, S., Unnikrishnan, M., Dr. Praveen Varma, and Rathod, R. Chandra, “Surgical interruption of patent ductus arteriosus in a child with severe aortic stenosis: anesthetic considerations.”, J Cardiothorac Vasc Anesth, vol. 19, no. 6, pp. 784-5, 2005.

2004

K. G. Shyamkrishnan, Dr. Praveen Varma, Neelakandhan, K. S., and Tharakan, J. M., “Ascending aortic coarctation with mitral regurgitation-surgical outcome—A case report”, vol. 20, no. 1, pp. 23 - 24, 2004.

2004

R. Duara, Sarma, A., Dr. Praveen Varma, Unnikrishnan, M., Kumar, R., and Neelakandhan, K. S., “Aortic root replacement—The “Chitra” experience”, Indian Journal of Thoracic and Cardiovascular Surgery, vol. 20, no. 1, pp. 38-39, 2004.

2004

K. Nair, Dr. Praveen Varma, Krishnamoorthy, K. M., Chandrabhanu, P., Dora, S. K., Edwin, F., Pradeep, K. D., Harikrishnan, S., Sivasankaran, S., Ajithkumar, V. K., Titus, T., Tharakan, J. A., and Neelakandhan, K. S., “Long-Term Follow-up of Aortic Valve Replacement with Starr-Edwards Prosthesis”, Indian Heart J. , vol. 56, no. 5, 2004.

2004

M. S. Harikrishnan, Nair, K., Krishnamoorthy, K. M., Tharakan, J. A., Dr. Praveen Varma, Dora, S. K., Harikrishnan, S., Titus, T., Ajithkumar, V. K., Sivasankaran, S., Rajeev, E., Namboodiri, K. K. N., and Neelakandhan, K. S., “Long-term Follow-up of Mitral Valve Replacement in Children”, Indian Heart J., vol. 56, no. 5, 2004.

2004

M. S. Harikrishnan, Nair, K., Krishnamoorthy, K. M., JA, T., Dr. Praveen Varma, Dora, S. K., Harikrishnan, S., Titus, T., Ajithkumar, V. K., Sivasankaran, S., Rajeev, E., Namboodiri, K. K. N., and Neelakandhan, K. S., “Long-Term Follow-up of Aortic Valve Replacement in Children”, Indian Heart J. , vol. 56, no. 5, 2004.

2004

E. Rajeev, S., H., Dr. Praveen Varma, Nair, K., Namboodiri, K. K. N., Dora, S. K., Krishnamoorthy, K. M., Sivasankaran, S., Kumar, A., Titus, T., Tharakan, J. A., and Mukundan, C., “Cortriatriatum Sinister – Profile of 10 Cases.”, Indian Heart J. , vol. 56, no. 5, 2004.

2004

P. Kumar Neema, Sinha, P. Kumar, Dr. Praveen Varma, and Rathod, R. Chandra, “Simultaneous repair of bilateral multiple emphysematous bullae with a secundum atrial septal defect.”, J Cardiothorac Vasc Anesth, vol. 18, no. 5, pp. 632-6, 2004.

2004

S. Vitthal Gadhinglajkar, Sreedhar, R., and Dr. Praveen Varma, “Controlled aortic root perfusion: a novel method to treat refractory ventricular arrhythmias after aortic valve replacement”, Journal of cardiothoracic and vascular anesthesia, vol. 18, no. 2, pp. 197–200, 2004.[Abstract]


THE OCCURRENCE OF malignant ventricular arrhythmias after aortic valve surgery may be a cause of failure to wean patients from cardiopulmonary bypass (CPB). Electrical cardioversion or defibrillation and antiarrhythmic drugs may fail to treat arrhythmias and establish sinus rhythm.

More »»

2004

Dr. Praveen Varma, Misra, M., Radhakrishnan, V. Venkatrama, and Neelakandhan, K. Sankaran, “Fatal post-operative gastro intestinal hemorrhage because of angio-dysplasia of small intestine in aortic regurgitation”, Interactive cardiovascular and thoracic surgery, vol. 3, no. 1, pp. 118–120, 2004.[Abstract]


Gastrointestinal bleeding due to angiodysplasia of the large intestine associated with calcific aortic stenosis is a well-known entity. Angiodysplasias are artero-venous malformations and they form one of the common causes of occult gastro-intestinal bleeding in the elderly. A 59-year-old man underwent aortic valve replacement for severe aortic regurgitation, developed severe gastro intestinal bleeding. Selective angiography was inconclusive. Exploratory laparotomy revealed angiodysplasia of the terminal ileum, which was resected. We report this case to draw attention to this rare cause of gastro intestinal bleeding and the difficulty in arriving at a diagnosis by the usual investigations.

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2004

Dr. Praveen Varma, Warrier, G., Ramachandran, P., Neema, P. Kumar, Manohar, S. Rema Krish, Titus, T., and Neelakandhan, K. Sankaran, “Partial atrioventricular canal defect with cor triatriatum sinister: report of three cases”, The Journal of thoracic and cardiovascular surgery, vol. 127, no. 2, pp. 572–573, 2004.[Abstract]


Cor triatriatum is an uncommon but surgically correctable cause of pulmonary venous hypertension and congestive cardiac failure, with a reported incidence of 0.1% among children with congenital heart diseases. Association with partial atrioventricular canal defect (PAVCD) is even rarer, with only anecdotal reports appearing in the literature. In the classic form, cor triatriatum is characterized by the presence of a fibromuscular diaphragm that subdivides the left atrium into a proximal accessory chamber and a distal true chamber. More »»

2003

Dr. Praveen Varma, Anbarasu, M., Sreenivas, V. Gadhinglda, and Neelakandhan, K. Sankaran, “Dysphagia lusorum.”, Asian Cardiovasc Thorac Ann, vol. 11, no. 4, p. 376, 2003.

2003

Dr. Praveen Varma, Dharan, B. S., Ramachandran, P., and Neelakandhan, K. Sankaran, “Superior vena caval aneurysm”, Interactive CardioVascular and Thoracic Surgery, vol. 2, no. 3, pp. 331-333, 2003.[Abstract]


Venous aneurysms arising from the mediastinal systemic veins are rare. There are only 27 reported cases of such aneurysms. Majority arise from the superior vena cava. We are reporting a saccular aneurysm of superior vena cava in a 58-year-old male. The chest radiogram suggested superior mediastinal mass and the computed tomogram was suggestive of aortic arch aneurysm. Aortography and venography confirmed the diagnosis as saccular aneurysm arising from the superior vena cava. A 7 cm saccular aneurysm arising from the distal half of superior vena cava was resected through median sternotomy. The surgery was done to prevent pulmonary thrombo-embolism.

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2003

Dr. Praveen Varma, Latha, M., Purushotham, S. Nambala, and Neelakandhan, K. Sankaran, “Abdominal aortic occlusion due to aorto arteritis”, European Journal of Cardio-Thoracic Surgery, vol. 24, no. 3, p. 451, 2003.[Abstract]


A 34-year-old man was evaluated for recent onset of bilateral lower limb claudication. On clinical evaluation, he was hypertensive [B.P. 220/140 on right arm] with feeble lower limb pulses. Radiofemoral delay and abdominal bruit were present. He was evaluated by aortogram which showed segmental occlusion below the level of superior mesenteric artery, with reformation through inferior mesenteric artery. At surgery, the periaortic tissue and the aortic wall were thickened. Aorto-renal end-arterectomy with patch aortoplasty and end-arterectomy of right common iliac artery were performed. The patient was discharged with B.P. of 150/100 mmHg on anti-hypertensive medications. Histo-pathology confirmed the diagnosis as Aorto-arteritis

More »»

Reviewer

  • International Journal of Cardiology
  • Annals of Thoracic Surgery
  • European Journal of Cardio-Thoracic Surgery
  • Annals of Cardiac Anaesthesia
  • Indian Journal of Cardiothoracic and Vascular Surgery

Editorial Board

  • Annals of Cardiac Anaesthesia

Professional Interest

  • Mitral Valve Repair, Ischemic Mitral Regurgitation
  • Heart Failure and Transplantation
  • Hypertrophic Cardiomyopathy
  • Outcome Research, DataBase
  • Resident Education

Professional Memberships

  • Indian Medical Association
  • CTS Net

Projects

  • Onsite PI -Coronary Trial (On pump vs. off-pump CABG) (2014-16) - Results published in NEJM
  • Onsite PI-Phase 3 clinical trial of Daffodil™ VALVE (2018- )-Merril Life Sciences Pvt. Ltd, Gujarat, India
  • Onsite PI -Preserve Mitral study-CG Future ring (2018- )- Medtronic Pvt. Ltd., Mumbai, Maharashtra, India
  • Development of Homograft Bank (2002-2004) - Pilot study-STEK Sponsored

Workshops and Seminars Organized

  • Mitral Valve Repair by Prof Dr. Sampath Kumar, All India Institute of medical Sciences-2003
  • Aortic Root Replacement by Dr. Joachim Lass, Bad Bevenson Hospital, Germany- 2003
  • Minimally Invasive Valve Surgery by Dr. Prem Shekhar, Brigham and Women’s Hospital, Boston-2012
  • Seminar on Heart Failure Surgery by Dr. Prem S Shekhar MD, Dr. Luigino Nascimben MD, Mr. Giovanni Cercere (ACP), BWH, Boston-2012
  • CME on Amrita Heart Valve Conclave 2015- Mitral Valve Repair at Amrita Institute of Medical Sciences, Kochi-2015.
  • CME on Amrita Heart Valve Conclave 2016- Aortic Valve Repair at Amrita Institute of Medical Sciences, Kochi-2016.
  • CME on Amrita Heart Conclave 2017- MICS CABG at Amrita Institute of Medical Sciences, Kochi-2017.
  • CME on Amrita Heart Conclave 2018- A workshop on Aortic Root Surgery in Amrita Institute of Medical Sciences, Kochi-2018.

Additional Professional Activities

  • Member, Hospital Transfusion Committee (2003 -2004).
  • Member, six-sigma project (2002).
  • Co-Investigator, Homograft Project (2003 -2004), Project grant from Ministry of Science and Technology.
  • Associate Investigator in animal experiments, unicentric and multicentric trial for development of membrane oxygenator (1999-2004).
  • Blood Conservation in Valvular Heart Diseases (2002-2003).
  • Chief Investigator. DataBase for valve surgery. Project Grant from Edward Life Sciences.
  • Member Board of studies for cardiac surgery, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum (2010-2012). Revised the curriculum, developed teaching modules and evaluation protocol for Cardio-Thoracic Residents.
  • Program-in-Charge, Division of Cardiac Surgery, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum (2011- 2012).
  • Member of following committees:
    • Junior staff selection (2010-13).
    • Resident Selection (2010-13).
    • Clinical Perfusionist Selection (2010-12).
    • Guidelines for Doctors in their relation to Industries and Pharma’s- Report submitted 2011.
    • Revision of working hours for employees-Report submitted in 2012.

Chairperson for Conferences

  • Aortic Valve Repair – Prof. Dr. Pedro Del Nido – PCSI Annual Conference 2011.
  • Live Workshop Mitral Valve Repair - Dr Patrick Perrier, Madras Medical Mission, Chennai- 2012.
  • IACTS Annual Conference Feb 2014.
  • Asia Pacific Valve Symposium-Bangalore 2014.

Invited Guest Lectures

  • “Heart Team”-Guidelines on Myocardial Revascularization – PIMS, Pondicherry 2011.
  • Syntax Trial- Madras Medical Mission, Chennai - 2012.
  • Heart Failure Surgery - Kerala Association of Clinical Perfusion 2012.
  • Post-operative care of cardiac surgery patients-Madras Medical Mission.
  • Relevance of Database- Lissie Hospital, Cochin -April 2014.