Right ventricular dysfunction and failure in chronic pressure overload

Abstract

Right ventricular (RV) dysfunction is the main cause of death in pulmonary arterial hypertension (PAH). Our understanding of the pathophysiology of RV dysfunction is limited but improving. Methods to better diagnose RV dysfunction earlier and treatments specifically designed to minimize or reverse the remodeling process are likely to improve outcomes. We review the current understanding of RV dysfunction in chronic pressure overload and introduce some novel insights based on recent investigations into pathophysiology, diagnosis, and treatment.

Figure 1

Regional heterogeneity of RV remodeling and dysfunction observed in patients with pulmonary hypertension. Patients were divided into one of three groups based upon hemodynamic parameters: Normal (normal pulmonary artery [PA] pressure, defined as mean PA pressure ≤25 mmHg), PH-C (PH with hemodynamically compensated RV function, defined as mean PA pressure >25 mmHg and right atrial [RA] pressure <10 mmHg), and PH-D (PH with hemodynamically decompensated RV function, defined as mean PA pressure ≥25 mmHg, and RA pressure ≥10 mmHg). (a) Regional RV wall thickness in end diastole (ED, filled symbols) and end systole (ES, open symbols). (b) Corresponding fractional wall thickening. *P < 0.05 PH-C versus Normal or PH-D versus Normal; ^†P < 0.05 PH-D versus PH-C, from [25].

Figure 2

Example of ventricular-vascular coupling analysis. Systolic portions of the RV pressure-volume curves showing end-systolic elastance (Ees) and arterial elastance (Ea) lines. Ventricular-vascular coupling (Ees/Ea) is improved with prostacyclin due to a decrease in arterial elastance (Ea) in a dog with acute RV failure induced by transient pulmonary artery constriction. (a) Prior to prostacyclin infusion. (b) After prostacyclin infusion. (c) Ventricular-vascular coupling efficiency (Ees/Ea) at baseline, during pulmonary artery constriction (Constr.), after pulmonary artery release, and during prostacyclin infusion at 2 doses (n = 7; values are means + standard error). ^#P < 0.05 compared with baseline; ^§P < 0.05 compared with release, adapted from [27].