Sivaramakrishna Iyer Padmavati commonly known as S. I. Padmavati or S. Padmavati (born 20 June 1917) is an Indian cardiologist. She is director of the National Heart Institute, Delhi and the founder president of the All India Heart Foundation. The institute collaborates with the World Health Organisation (WHO) in training students in preventive cardiology.
Padmavati, an elected fellow of the National Academy of Medical Sciences, was the first woman cardiologist in India in 1954 and established the first cardiac clinic and cardiac cath lab in North India. She was the President of 5th World Congress of Cardiology, New Delhi (1966), and was awarded India's second highest civilian honour the Padma Vibhushan in 1992 
Dr Padmavati was born to a barrister in Burma (Myanmar). She had three brothers and two sisters 
She received a MBBS degree from Rangoon Medical College, Rangoon and later moved to London in 1949, where she received a FRCP from Royal College of Physicians, London followed by FRCPE from Royal College of Physicians of Edinburgh. Here while working at hospitals like, the National Heart Hospital, National Chest Hospital, and the National Hospital, Queen Square, London, she developed interest in cardiology.
Subsequently, after finishing her FRCP, she moved to Sweden for three months, where she took cardiology courses at the Southern Hospital  Meanwhile, she applied for fellowship at the Johns Hopkins Hospital, Baltimore, part of Johns Hopkins University U.S., and was selected, and went on to study with noted cardiologist Dr. Helen Taussig. In 1952, she joined Harvard Medical School (Harvard University), where she studied under Dr. Paul Dudley White, a pioneer in modern cardiology.
Back in India, she started her career in 1953, as a lecturer at Lady Hardinge Medical College, Delhi, where she opened a cardiology clinic. In 1954, she was among the first few women cardiologists in India, later as an examiner with Medical Council of India she started the first DM in cardiology in India.
She joined Maulana Azad Medical College, Delhi in 1967, and was awarded the Padma Bhushan, by Government of India in the same year. She established one of the first departments of cardiology, at the G. B. Pant Hospital, which is within the college campus. She retired as the Director (Principal) of the college, in 1978. She formed All India Heart Foundation (AIHF) in 1962, group of physicians and industrialist Ashok Jain of Bennett, Coleman & Co. Ltd.
Post retirement, she set up the National Heart Institute (NHI) under AIHF, in South Delhi, the hospital was opened in 1981, which expanded in following years to include tertiary patient care, research and population outreach, and where she continues to work.
Today, she is an Emeritus Professor of Medicine and Cardiology of the University of Delhi. She was awarded India's second highest civilian honour the Padma Vibhushan in 1992, by Government of India. She turned 100 in June 2017.