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

When Eugene Braunwald addressed the Right Heart Failure Summit in 2012, he echoed the sentiments of cardiologists throughout history by saying that he had “not paid [his] dues to the right ventricle” [1]. For years, the right ventricle was viewed as merely a conduit for transmitting blood to the lungs, a thought buttressed by the relatively preserved cardiac output seen in patients who underwent the Fontan operation [2]. In 1943, Starr et al. [3] found that venous pressure failed to augment after near-complete cauterisation of the right ventricular free wall, again supporting the concept that right ventricular function has very little effect on systemic venous pressure. What Starr et al. [3] failed to realise, but was later demonstrated by Damiano et al. [4], is that his model failed to account for the continued function of the interventricular septum, which was sufficient to propel blood through a pulmonary vascular circuit with normal resistance. Diminished right ventricular contractile reserve may improve prognostic assessment of PAH