No abstract

Right ventricular (RV) response to exercise or pharmacological stress is not well documented in pulmonary hypertension (PH). We investigated the relationship between RV reserve and ventricular-arterial coupling.Surgical ligation of the left pulmonary artery was performed in 13 Large White piglets (PH group), thereafter weekly embolisations of the right lower lobe were performed for 5 weeks. A control group of six piglets underwent sham procedures. Right heart catheterisation and echocardiography were performed at week 6. Pressure-volume loops were recorded before and after dobutamine infusion.Induction of experimental PH resulted in a higher mean±SD pulmonary artery pressure (34±9 versus 14±2 mmHg; p<0.01) and in a lower ventricular-arterial coupling efficiency (0.66±0.18 versus 1.24±0.17; p<0.01) compared with controls at 6 weeks. Dobutamine-induced relative changes in RV stroke volume index (SVI) and end-systolic elastance were lower in the PH group (mean±SD 47±5% versus 20±5%, p<0.01, and 81±37% versus 32±14%, p<0.01, respectively). Change in SVI was strongly associated with resting ventricular-arterial coupling (R 2 =0.74; p<0.01). RV reserve was associated with ventricular-arterial coupling in a porcine model of chronic pressure overload. @ERSpublications Dobutamine testing in right ventricular pressure overload: a potentially useful method to assess contractile reserve