Is cardiac resynchronization therapy for right ventricular failure in pulmonary arterial hypertension of benefit?

Abstract

Pulmonary arterial hypertension is a manifestation of a group of disorders leading to pulmonary vascular remodeling and increased pulmonary pressures. The right ventricular (RV) response to chronic pressure overload consists of myocardial remodeling, which is in many ways similar to that seen in left ventricular (LV) failure. Maladaptive myocardial remodeling often leads to intraventricular and interventricular dyssychrony, an observation that has led to cardiac resynchronization therapy (CRT) for LV failure. CRT has proven to be an effective treatment strategy in subsets of patients with LV failure resulting in improvement in LV function, heart failure symptoms, and survival. Current therapy for pulmonary arterial hypertension is based on decreasing pulmonary vascular resistance, and there is currently no effective therapy targeting the right ventricle or maladaptive ventricular remodeling in these patients. This review focuses on the RV response to chronic pressure overload, its effect on electromechanical coupling and synchrony, and how lessons learned from left ventricular cardiac resynchronization might be applied as therapy for RV dysfunction in the context of pulmonary arterial hypertension.

Keywords: cardiac resynchronization therapy; dyssynchrony; pulmonary arterial hypertension; pulmonary hypertension; right ventricular failure.

Figure 1

The right ventricular (RV) response to chronic pressure overload leading to intraventricular and interventricular dyssynchrony. RV pacing could potentially inhibit or reverse maladaptive remodeling. LV: left ventricle/ventricular; MHC: myosin heavy chain.