Dr. S. Ramakrishnan did his undergraduate training form Madurai medical college and MD (Medicine) from King George Medical College, Lucknow. He joined the Department of Cardiology at the AIIMS as a senior resident in 2001.  After completing his DM in 2004, he worked as a faculty member at the GB Pant hospital, New Delhi before rejoining AIIMS as Assistant Professor in October 2005. Presently promoted as Professor in the Department of Cardiology, All India Institute of Medical Sciences, New Delhi, Dr Ramakrishnan is actively involved in clinical research, patient care, and educational activities.

Dr. Ramakrishnan has authored around 170 publications in indexed journals and his papers have been cited more than 3500 times. He has won numerous awards including D P Basu award, Nanda award, Sujoy B Roy award, Best poster awards in ACC, AEPC and APPCS, Young investigator award in PCSI, APPCS and Col Chopra award. He is involved in providing tertiary patient care services to a vast majority of population, with the quality of care comparable to any cardiac center in the world. 

He has also organized several updates, national and international conferences and cardiology workshops. As a faculty member at AIIMS, he has been predominantly involved in Clinical Cardiology & interventional cardiology. Apart from his academic, clinical and research work he has attained a high degree of proficiency in interventions. He has performed a few innovative interventions and he is among the first to use alcohol ablation for RVOT obstruction.

Dr Ramakrishnan is also awarded a Fellowship of the ACC (American college of Cardiology) and FSCAI.