Abstract 1654: Reduced Left Ventricular Diastolic Function Follows Prolonged Strenuous Exercise In Middle-aged Male Athletes

Abstract

Introduction: A number of studies have demonstrated LV diastolic dysfunction after prolonged strenuous exercise. However, data remain conflicting in part because of uncontrolled and disparate experimental conditions. Hypothesis: We assessed the hypothesis that a decline in LV diastolic function follows prolonged exercise among middle aged male athletes. Methods: Eight middle aged recreational male athletes (ages 47–59, mean 52.4± 1.3 years) were recruited. On separate days at least one week apart, subjects performed continuous running of 150 min duration at low and high intensities (55% vs 80% VO2 max, respectively). On each day of exercise, subjects underwent echocardiographic assessments immediately before and 60 min following exercise. Diastolic function was assessed by standard pulsed wave Doppler and tissue Doppler techniques. Efforts were made to maintain hydration throughout, and hematocrit was checked with each echocardiographic assessment. Results: Sixty minutes following prolonged exercise, the mean resting heart rate was significantly elevated compared to baseline (81±5 vs 63±3 bpm, p<0.01) and a drop in systolic blood pressure was observed (115±4 vs 132±5mmHg, p=0.02). Baseline and post-exercise hematocrit were similar (43.3%±0.8 vs 43.4%±0.8). Mean (±sem) indices of diastolic function are summarized below and included a significant decline in peak mitral inflow E velocity, accompanied by an increase in mitral inflow A velocity which was significant after high intensity exercise. The decline in both the E/A and e’/a’ ratio was significant for both high and low exercise intensities. A significant prolongation in the IVRT and the mitral inflow E wave deceleration time were seen following low intensity exercise. Conclusions: In middle aged men, prolonged exercise is associated with diminished resting LV diastolic performance, detectable one hour following exercise. These changes appear to be independent of hydration state.