Using four-dimensional (4D) cardiac computed tomography (CCT) scans at rest and immediately after exercise, we examined the right heart chamber sizes and systolic function and its association with exercise capacity in left ventricular assist device (LVAD) recipients. Fifteen patients with HeartMate (HM) II or 3 underwent echocardiography and maximal cardiopulmonary exercise test. Subsequently, contrast-enhanced CCT scans were performed at rest and immediately after two minutes of supine 25 Watt ergometer bike exercise. Patients were (60 ± 12 years of age) 377 ± 347 days postimplant. Peak oxygen uptake (pVO2) was 15 ± 5 ml/kg/min. LV ejection fraction measured by echocardiography was 15 ± 9%. Pump speed was 9500 ± 258 in HM II and 5518 ± 388 rpm in HM 3 recipients. Resting right atrial ejection fraction (RAEF) was 18 ± 9%, and right ventricular ejection fraction (RVEF) was 36 ± 8%. During stress, RAEF was 19 ± 10%, and RVEF was 37 ± 8%. RAEF and RVEF did not correlate significantly with pVO2 at rest or during stress. Resting-RAEF and stress RAEF correlated significantly: r = 0.87, p < 0.01 as did resting RVEF and stress RVEF: r = 0.76, p < 0.01. In conclusion, resting-EF predicted stress-EF for both RA and RV in patients with an LVAD. Neither RVEF nor RAEF correlated with pVO2.