Original Research Article http://doi.org/10.18231/j.ijpca.2019.009 International Journal of Pharmaceutical Chemistry and Analysis, April-June, 2019;6(2):49-52 49 Correlation between V O2max and systolic time interval in athletes Mrunalini Kanvinde 1 *, Vivek Nalgirkar 2 1 Lecturer, 2 Professor and HOD, 1,2 Dept. of Physiology, 1,2 Dr. D Y Patil Medical College Nerul, Navi Mumbai, Maharashtra, India *Corresponding Author: Mrunalini Kanvinde Email: vaishnav5bale@gmail.com Abstract The goal of my study was to correlate    2max and systolic time interval as a evaluator of cardiovascular fitness in athletes. Depending on the need of oxygen to tissues    2max increases with a increase in cardiac output, stroke volume, left ventricular ejection fraction and myocardial activity as a athlete does treadmill from moderate to maximal, Data collection was done at Stress test lab. at Nerul, Navi Mumbai after taking permission from medical ethic committee. Athletes were asked to do treadmill and their    2max and systolic time interval were assessed with their duration of exercise by taking their BMI into consideration. For proper results, athletes were asked to do treadmill for 2 weeks In athletes, after doing unpaired T - test a gradual increase in systolic time interval as left ventricular ejection phase and duration of systole (P<0.001) left ventricular ejection fraction was somewhat increased (P<0.005) without any change in pre-ejection phase with increase in    2max (P<0.001).as athlete perform treadmill. Thus in athletes,    2max is much more correlated with systolic time intervals (P<0.001). Conclusion: Thus it was concluded that in athlete,    2max is directly correlated with systolic time interval. Keywords:    2max , Treadmill, Athletes, Systolic time intervals, Left ventricular ejection fraction. Introduction Student of cardiovascular physiology have recognized left ventricular ejection time as main parameters of cardiac function, which is closely related to    2max in athletes. Along with left ventricular ejection fraction, left ventricular performance can be assessed through systolic time interval which is affected by    2max.    2max and systolic time interval gives as important guidance about oxygen requirement of heart per beat. As exercise intensity increase, oxygen consumption reaches point where exercise intensity can continue to increase without                  2max, which is an important component of health-related physical fitness Endurance conditioning increases work capacity, reduces myocardial oxygen demand, increases potential oxygen supply. During endurance training, increase in stroke volume of an individual creates a heightened ability of the left ventricle to fill more completely during the diastole phase. Enhancement of the intrinsic contractile properties of the myocardium, response to inotropic stimulation and extramyocardial adaptations that have secondary effects on performance of left ventricle --e.g, increased ventricular filling or decreased myocardial work. Materials and Methods Data Collection Data collection was done at Stress test lab. at Nerul, Navi Mumbai after taking permission from medical ethic committee which included 40 athletes from age-group 18 - 24 years. During this study, criteria kept were, BMI should be 18–24.6m2/kg (according to National Institute of Health Science), and subject should have a 2 –3 hours gap between diet and exercise and should not have cardio respiratory or orthopedic disease. 7 Parameters chosen were age, height, weight, systolic time intervals (pre-ejection phase, Left ventricular ejection phase, duration of systole. i.e. total electromechanical systole) derived from Echocardiography and    2max After signing informed consent form, athletes were asked to do treadmill by using Bruce protocol. Duration of exercise was also taken into consideration. Systolic Time Intervals Systolic time intervals. I.e. pre - ejection phase (PEP), Left ventricular ejection time (LEFT), duration of systole. i. e. total electromechanical systoles (QS2) were measured through 3D echocardiography 3Dechocardiophy by D’ , w w      systolic time intervals, In this transducer used is of frequency 21HZ, velocity – 2 to 2.5 megavolt, 7 Measurement of systolic time intervals Duration of systole (QS2) = Pre-ejection phase (PEP) + Left ventricular ejection time (LVET). Normal range for pre-ejection phase -129 msec, Normal range for Duration of systole – 539 msec. Normal range for LVET410 msec (13) Thus correlation between    2max and systolic time interval was found in athletes, Statistical analysis – For doing statistical analysis, depending on the parameters, unpaired T-test was applied and their significant level (P- value) was found out.