부산대학교 도서관

Introduction: The right ventricle (RV) in aortic stenosis (AS) has been largely neglected due to the belief that changes occur only late in association with left ventricular (LV) dysfunction and pulmonary hypertension (PH).Hypothesis: RV may be directly influenced by LV afterload before overt PH. We sought to examine early effects of LV afterload and its relief on RV function and strain in AS.Methods: 105 participants (77 isolated moderate/severe AS and 28 matched controls) were prospectively enrolled: LV dysfunction, cardiomyopathies and PH excluded. Follow-up was at 8±2 months post aortic valve replacement (AVR). Cardiovascular magnetic resonance (CMR) quantified RV function, strain and the LV including mass changes.Results: RV ejection fraction (RVEF) significantly increased with AS severity (moderate AS: RVEF 62±4%, asymptomatic severe AS: 68±7%, symptomatic severe AS: 74±4%, p<0.001). The RV hypercontractile state was confirmed by elevated RV strain, especially in symptomatic AS compared to controls (RV circumferential strain: -17±4% vs -14±4%, p=0.02; RV radial strain: 31±9.6% vs 24±7%, p=0.01). RVEF correlated strongly with symptomatic status (r=0.66, p<0.001) and AS degree (peak aortic velocity r=0.62, p<0.001). An RVEF ≥71% had an 83% accuracy in detecting symptoms (AUC on ROC analysis 0.89, p<0.001) with a negative and positive predictive value of 90% and 76%, respectively. All symptomatic AS had an RVEF ≥63%. RVEF strongly correlated to LV recovery after AVR (LV mass regression r=0.61, p=0.01) and was the most powerful independent predictor of LV mass regression. RV parameters were restored post AVR towards normal.Conclusions: In AS, increased RV contractility correlated with severity and symptomatic status. RVEF detected symptoms of valve obstruction and was the strongest independent predictor of LV mass regression. Thus, RV function may be a new early marker of decompensation and LV myocardial recovery ability, useful in risk stratification.