Dr. Harikrishnan M. S. is Clinical Professor in the Department of Cardiology at Amrita Institute of Medical Sciences. His fields of interest are coronary interventions, cardiac electrophysiology and heart failure.

Dr. Harikrishnan M. S. graduated from T.D. Medical College, Alappuzha in 1995. He obtained his MD (Internal Medicine) degree from Government Medical College, Trivandrum. He completed Cardiology Residency at Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum for DM Cardiology degree in 2004.

He has expertise in noninvasive investigative modalities like echocardiography, Holter evaluation, nuclear cardiac imaging and stress testing. He is a skilled interventionalist with special focus on complex coronary interventions including use of rotablation and retrograde techniques for crossing chronic total occlusions.

In 2014, Dr. Harikrishnan completed a one-year Clinical Cardiac Electrophysiology fellowship training at Case Western Reserve University, Cleveland , USA under the guidance of Professor Mauricio Arruda, one of the leading cardiac electrophysiologists in USA. Dr Harikrishan has expertise in cardiac electrophysiology procedures like conventional ablations, complex arrhythmia ablations using electroanatomic mapping including atrial fibrillation ablation and ventricular tachycardia ablation using epi-endo techniques, device implants ranging from pacemakers, defibrillators and cardiac resyncrhonisation devices. He is also skilled in performing lead extractions.

He has several years of experience as a postgraduate teacher for trainees in Cardiology and has presented papers and posters at various conferences.


Publication Type: Journal Article

Year of Publication Title


M. Subramanian, Prabhu, M. A., Rai, M., Harikrishnan M. S., Saritha Sekhar, Praveen G. Pai, and Natarajan, K. U., “A novel prediction model for risk stratification in patients with a type 1 Brugada ECG pattern.”, J Electrocardiol, vol. 55, pp. 65-71, 2019.[Abstract]

<p><b>BACKGROUND: </b>Risk stratification in Brugada syndrome remains a controversial and unresolved clinical problem, especially in asymptomatic patients with a type 1 ECG pattern. The purpose of this study is to derive and validate a prediction model based on clinical and ECG parameters to effectively identify patients with a type 1 ECG pattern who are at high risk of major arrhythmic events (MAE) during follow-up.</p>

<p><b>METHODS: </b>This study analysed data from 103 consecutive patients with Brugada Type 1 ECG pattern and no history of previous cardiac arrest. The prediction model was derived using logistic regression with MAE as the primary outcome, and patient demographic and electrocardiographic parameters as potential predictor variables. The model was externally validated in an independent cohort of 42 patients.</p>

<p><b>RESULTS: </b>The final model (Brugada Risk Stratification [BRS] score) consisted of 4 independent predictors (1 point each) of MAE during follow-up (median 85.3 months): spontaneous type 1 pattern, QRS fragments in inferior leads≥3,S wave upslope duration ratio ≥ 0.8, and T peak - T end ≥ 100 ms. The BRS score (AUC = 0.95,95% CI 0.0.92-0.98) stratifies patients with a type 1 ECG pattern into low (BRS score ≤ 2) and high (BRS score ≥ 3) risk classes, with a class specific risk of MAE of 0-1.1% and 92.3-100% across the derivation and validation cohorts, respectively.</p>

<p><b>CONCLUSIONS: </b>The BRS score is a simple bed-side tool with high predictive accuracy, for risk stratification of patients with a Brugada Type 1 ECG pattern. Prospective validation of the prediction model is necessary before this score can be implemented in clinical practice.</p>

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A. C. Ratheendran, Subramanian, M., Bhanu, D. K., Prabhu, M. A., Kannan, R., Natarajan, K. U., S Sekhar, S., Thachathodiyil, R., Harikrishnan M. S., and Pai, P. G., “Fragmented QRS on electrocardiography as a predictor of myocardial scar in patients with hypertrophic cardiomyopathy.”, Acta Cardiol, pp. 1-5, 2019.[Abstract]

BACKGROUND: Fragmented QRS (fQRS) and Q waves are ECG findings in patients with myocardial scar. fQRS is more sensitive than pathological Q waves in detecting myocardial fibrosis in patients with coronary artery disease (CAD). Cardiac magnetic resonance (CMR) imaging is used for the diagnosis and for quantifying scar tissue in patients with HCM. Our aim was to correlate ECG parameters like fQRS and Q waves with the presence of late gadolinium enhancement (LGE) assessed by contrast CMR imaging to elucidate ECG markers which might predict scar tissue in HCM.

METHODS: This study is a retrospective analysis which included 39 patients who were diagnosed/suspected to have HCM on echocardiography and referred for contrast CMR imaging at our centre between 2010 and 2016. Presence of fQRS was correlated with scar demonstrated by LGE on CMR.

RESULTS: Twenty four (66.67%) patients had asymmetrical septal hypertrophy, 7 (19.44%) patients had apical involvement while 5 (13.89%) had concentric pattern. Only 4 (11.11%) patients had pathological Q waves in contiguous leads on surface ECG while fQRS in two contiguous leads was present in 23 (63.89%) patients. Presence of fQRS was more in patients with LGE on CMR than those without (84.61 versus 10%, p<.001). When presence of LGE in specific segments (anterior, lateral and inferior) was correlated with corresponding ECG leads, all the three segments showed significant correlation. The overall sensitivity, specificity, PPV and NPV of fQRS for predicting scar tissue were 84.6, 90.0, 95.6 and 69.2%, respectively.

CONCLUSION: fQRS on surface ECG can be used as an indirect marker to predict the presence of fibrosis in HCM.

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