Purpose: Our main purpose was to find out how tension time index can be used to evaluate exercise performance through treadmill. As a subject goes on doing exercise from moderate to maximal, need of oxygen to tissues increases, resulting increased cardiac output, stroke volume, increased left ventricular ejection fraction, increased myocardial activity which is mainly determined by tension time index.
Material and Method: After getting approval from medical ethics committee this study was carried in Stress Test Lab at Dr. D. Y. Patil Hospital & Research center, Nerul, Navi Mumbai. In this study, Athletes (30) and non-athletes (30) were exercised Treadmill for different duration for 3 times a week. (Till to get 90% of maximal, age-predicted heart-rate). Parameters chosen were systolic time intervals (Pre-ejection phase, Left ventricular ejection phase, duration of systole. i.e. total electromechanical systole) were derived from Echocardiography while Tension time index was calculated as Tension Time index = systolic pressure x duration of systole x pulse While calculating Tension time index, duration of systole which is in msec. is converted into minute.
Result: Left ventricular ejection fraction was somewhat increased (P<0.005) while systolic time intervals as left ventricular ejection phase, duration of systole and tension time index was found to be much more increased (P<0.001) without any change in pre-ejection phase and recovery time after performing treadmill. This shows that regular exercise from moderate to maximum affect left ventricular functions.
Conclusion: Thus it was concluded that as a subject goes on doing exercise from moderate to maximum, depending on the need of oxygen, tension time index also increases, showing tension time index as a best evaluator of exercise performance.