Temporal RV dysfunction after ischemia inhumans

Abstract: Background - We sought to determine if right ventricular (RV) stunning could be detected after supply (during coronary balloon occlusion (BO)) and supply/demand ischemia (induced by rapid pacing (RP) during transcatheter aortic valve replacement (TAVR)) in humans. Methods and Results - Ten subjects with single-vessel right coronary artery (RCA) disease undergoing PCI with normal ventricular function were studied in the BO group. Ten subjects undergoing transfemoral TAVR were studied in the RP group. In both, a conductance catheter was placed into the RV, and pressure volume (PV)-Loops were recorded at Baseline (BL) and for intervals over 15 minutes after a low-pressure BO for 1- minute or a cumulative duration of RP for up to 1-minute. Ischemia induced diastolic dysfunction was seen 1-minute after RP (EDP (mmHg): 8.1±4.2 vs. 12.1±4.1, p<0.001) and BO (EDP (mmHg): 8.1± 4.0 vs. 8.7±4.0, p=0.03). Impairment of systolic and diastolic function after BO remained at 15-minutes recovery (EF (%): 55.7±9.0 vs. 47.8±6.3, p<0.01; EDP (mmHg): 8.1±4.0 vs. 9.2±3.9, p<0.01). Persistent diastolic dysfunction was also evident in the RP group at 15-minutes recovery (EDP (mmHg): 8.1±4.1 vs. 9.9±4.4, p=0.03) and there was also sustained impairment of load-independent indices of systolic function at 15-minutes after RP (Ees/Ea (mmHg.ml-1): 1.25±0.31 vs. 0.85±0.43, p < 0.01). Conclusions - Rapid pacing and RCA balloon occlusion both cause ischemic RV dysfunction with stunning observed later during the procedure. This may have intraoperative implications in patients without RV functional reserve.