Effects of High Intensity Exercise on Biventricular Function Assessed by Cardiac Magnetic Resonance Imaging in Endurance Trained and Normally Active Individuals

Although several investigations have demonstrated that prolonged aerobic exercise results in decreased left ventricular (LV) function, few have examined the impact of an acute bout of high-intensity exercise on right ventricular (RV) and LV systolic and diastolic function. Cardiac magnetic resonance imaging with tagging was used to study the impact of high-intensity interval exercise on biventricular function in 9 endurance-trained (ET; Vo2max 69 ± 7 ml/kg/min) and 9 normally active (NA; Vo2max 44 ± 9 ml/kg/min) men. Subjects underwent baseline cardiac magnetic resonance imaging assessments (pre) and then performed an average of 14 1-minute intervals at 97 ± 11% (NA) and 99 ± 6% (ET) of peak power output, separated by 2 minutes of recovery at 21 ± 6% (NA) and 21 ± 9% (ET) of peak power output. After exercise, 2 cardiac magnetic resonance imaging assessments (post 1 at 6.2 ± 2.6 minutes and post 2 at 38.4 ± 3.8 minutes) were completed. RV and LV ejection fractions, twist, basal and apical rotation rates, rate of untwisting, circumferential strain, and timings were examined. No significant change in RV and LV ejection fractions, twist, untwisting rate, or strain after exercise occurred in the NA group. In the ET group, RV ejection fraction (pre 56 ± 4%, post 1 54 ± 4%, post 2 54 ± 3%) and LV ejection fraction (pre 62 ± 4%, post 1 59 ± 4%, post 2 58 ± 4%) were decreased at post 1 and post 2, while untwisting rate, apical rotation rate, and circumferential strain were decreased at post 2 (all p values <0.05). In conclusion, biventricular systolic and diastolic dysfunction occurred after 14 minutes of high-intensity exercise in ET athletes, a phenomenon not observed in NA subjects.