CARDIAC FUNCTION TIME INTERVALS ARE CORRELATED WITH MAXIMAL TREADMILL TIME IN COLLEGIATE WOMEN

Abstract

1869 Introduction: Seismocardiography (SCG) is a relatively new, non invasive technique developed for recording and analyzing cardiac vibratory activity as a measure of cardiac contractile performance. Purpose: The purpose of this study was to assess SCG derived cardiac contractile performance as a function of maximal treadmill time in collegiate women. Methods: Fifteen women (age range: 20-35 yrs.) participated in the study. Following informed consent, each participant performed a maximal graded exercise tolerance test (GXT) using the Bruce protocol. All GXT's were terminated upon volitional fatigue and upon achievement of age-predicted maximal HR. Maximal treadmill time was expressed in seconds and ranged from 600 to 1080 seconds among subjects. On a separate day, the following resting SCG derived cardiac function time intervals were determined: Left ventricular systolic time (LVST) (time for mitral valve closing to aortic valve closing), LV diastolic time (LVICT) (time for aortic valve closing to mitral valve closing), LV isovolumic contraction time (LVICT)(time for mitral valve closing to aortic valve opening) LV isovolumic relaxation time (LVIRT) (time for aortic valve closing to mitral valve opening), LV ejection time (LVET) (time for aortic valve opening to aortic valve closing), and Tei index (ratio of LVICT+LVIRT to LVET). Results: The below table summarizes the correlation between cardiac function time intervals (normalized to 1000 ms) and maximal treadmill time (sec). *indicates a significant correlation.TableSummary: LVST and LVET were positively correlated with maximal treadmill time. Whereas, LVDT, and Tei index were negatively correlated with maximal treadmill time. Conclusion: Cardiac function time intervals moderately predict maximal treadmill time in collegiate women.