Impaired Right Ventricular Contractile Reserve During Exercise in Endurance Athletes With Right Ventricular Arrhythmias

Introduction: Ventricular arrhythmias in endurance athletes (EAs) frequently originate from a mildly dysfunctional right ventricle (RV). We evaluated whether RV dysfunction in EAs with ventricular arrhythmias of RV origin (EA-VAs) becomes more apparent during exercise than at rest. Methods: Ten healthy EAs, 7 healthy non-athletes (NAs) and 17 EA-VAs (8 with ICD) first underwent cardiopulmonary exercise testing to determine maximal power (Pmax). Then, exercise echocardiography was performed at 25%, 50% and 66% of Pmax to measure the RV end-systolic pressure-area ratio (ESPAR), a surrogate of RV contractility, which was calculated as systolic pulmonary artery pressure/RV end-systolic area. Finally, all subjects without ICD underwent cardiac MRI during supine bicycle exercise at similar workloads with simultaneous invasive pulmonary artery pressure measurement to determine the RV end-systolic pressure-volume ratio (SP/ESV). Results: At rest, RV ESPAR was similar in EA-VAs relative to NAs (P=0.1), although slightly lower than in NAs (P=0.02). During exercise, EA-VAs had an impaired increase in RV ESPAR compared to both EAs and NAs (interaction P<0.0001; Figure 1A). Also the slopes of RV ESPAR to absolute workload (in Watts) were lower in EA-VAs than in EAs and NAs (P<0.0001) and correlated highly with the slopes of RV SP/ESV to workload obtained by MRI and invasive pressure measures (R=0.75; P<0.0001). Figure 1B shows that resting and peak exercise RV ESPAR cutoffs of 1.4 and 3.9 mmHg/cm2 had a sensitivity of 77% and 79% and specificity of 80% and 100%, respectively, to identify EA-VAs. Conclusion: EA-VAs have impaired RV contractility which is evident during exercise but hardly at rest. This strengthens the association between RV arrhythmias and functional impairment. Our data suggest that exercise echocardiography is sufficiently accurate to determine RV contractile reserve in a non-invasive manner and may assist in risk stratification of RV remodeling in EAs.

Publication year:2014