The effect of certain yogasanas on the heart is being scientifically investigated at the Institute of Cardiology, Government General Hospital, Madras. This study was undertaken in collaboration with yoga experts to gain a deeper understanding of the medical and scientific aspects of selected yogasanas and to determine their effects on the cardiovascular system. While the yogasanas, in general, were found to be beneficial, certain exercises viz. viparita karani, sarvangasana and halasana increased the work of the heart and decreased cardiac performance in persons with subnormal cardiac function.
Yogic exercises, therefore, should be prescribed jointly by yoga therapists and medical practitioners, Dr. Lakshmikanthan stated. The other investigators in his team were Dr. P. V. Bala-krishnan, assistant cardiologist, Thiru S. Krishnamurthy and Thiru Ramabadran, yoga experts.
Specifically the objectives of the study were:
The studies were undertaken on yoga experts, volunteers and cardiac patients with high blood pressure, ischaemic heart disease and patients who have cardiac failure.
The various physiological parameters, already indicated, were studied with modern electronic gadgets for the following asanas: shavasana, rama karani, viparita karani, sarvangasana, halasana, padmasana, and vajrasana.
The results indicated that shavasana and rama karani give rest to the heart of healthy volunteers and cardiac patients, and are likely to be useful for the treatment of high blood pressure and for rehabilitating a patient after heart attack because, in addition to giving rest to the heart, these improve the cardiac performance.
In viparita karani, sarvangasana and halasana the work of the heart is increased. In yoga experts and healthy volunteers the work of the heart increased and the cardiac performance improved. The physiological parameters simulate other physical exercises reputed to lower the risk factors associated with coronary artery disease. Hence these asanas may be helpful in the primary prevention of ischemic heart disease. However, in cardiac patients with sub-normal cardiac function, viparita karani, sarvangasana and halasana increased the work of the heart and decreased cardiac performance.
Asanas that increase and decrease the cardiac work can be combined for the rehabilitation of cardiac patients with good cardiac reserve. In cardiac patients with poor cardiac reserve only the asanas that decrease the cardiac work and improve the cardiac performance can be undertaken viz. shavasana and. rama karani, Dr. Lakshmikanthan said. Most of the cardiac patients who started practicing yogasanas after the preliminary investigations felt a sense of well-being, were more energetic and slept better than before.
In padmasana and vajrasana the cardiac work and cardiac performance were found to remain static.
"Our preliminary studies included other contemporary problems in cardiology like the effects of smoking, popularly practiced isometric exercises like bull worker in healthy volunteers and cardiac patients. Our results indicate that these have ill effects on the heart especially for the cardiac patient." Dr. Lakshmi Kanthan observed in concluding this paper.