Right ventricular reserve in a piglet model of chronic pulmonary hypertension

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

Stressing the stepchild: assessing right ventricular contractile reserve in pulmonary arterial hypertension

“…Likewise, the assessment of other echocardiographic parameters (RVFAC) might have provided superior discernment of impaired right ventricular contractile reserve. As noted earlier, GUIHAIRE et al [11] found RVFAC to have a stronger correlation than TAPSE with haemodynamic assessment of contractile reserve. Future studies should also consider assessment of right ventricular strain as a marker of right ventricular contractile reserve.…”

“…In short, GUIHAIRE et al [11] show that the absence of right ventricular contractile reserve is correlated with RV-PA uncoupling at rest in an animal model of PAH, a novel and important finding. However, this study leaves several important questions unanswered.…”

“…In this issue of the European Respiratory Journal (ERJ), two studies by GUIHAIRE et al [11] and SHARMA et al [12] take a novel approach to "stressing the stepchild", namely studying the use of dobutamine to assess right ventricular contractile reserve. Contractile reserve as a prognostic variable has long been the sole province of the left ventricle, predicting outcomes in valvular disease, ischaemic disease and cardiomyopathy [13][14][15].…”

“…Single-beat methods to calculate right ventricular Ees and Ees/Ea have been proposed but rely on assumptions that may not hold true under pathological conditions and require further validation [21][22][23]. Taken in combination, the studies by GUIHAIRE et al [11] and SHARMA et al [12] argue that assessment of right ventricular contractile reserve may provide such a tool.…”

“…GUIHAIRE et al [11] performed right ventricular pressure-volume analysis in a pig model of chronic pressure overload pulmonary hypertension. The study subjected 13 pigs to left pulmonary artery ligation followed by weekly injections of n-butyl-2-cyanoacrylate into the segmental arteries over a period of 5 weeks.…”