The Right Ventricle: From Embryologic Development to RV Failure

Abstract

Purpose of review: The right ventricle (RV) and left ventricle (LV) have different developmental origins, which likely plays a role in their chamber-specific response to physiological and pathological stress. RV dysfunction is encountered frequently in patients with congenital heart disease (CHD) and right heart abnormalities emerge from different causes than increased afterload alone as is observed in RV dysfunction due to pulmonary hypertension (PH). In this review, we describe the developmental, structural, and functional differences between ventricles while highlighting emerging therapies for RV dysfunction.

Recent findings: There are new insights into the role of fibrosis, inflammation, myocyte contraction, and mitochondrial dynamics in the pathogenesis of RV dysfunction. We discuss the current state of therapies that may potentially improve RV function in both experimental and clinical trials. A clearer understanding of the differences in molecular alterations in the RV compared to the LV may allow for the development of better therapies that treat RV dysfunction.

Keywords: Adult congenital heart disease; Congenital heart disease; Left ventricle; Pulmonary hypertension; Right ventricle; Right ventricular failure.

Fig. 1

Pathologic specimens. A Pathologic specimen of the right ventricle with the free wall removed to demonstrate the 3 anatomic regions [9]. B Pathologic specimen of the heart cut transversely demonstrating the crescent shape of the right ventricle [9]. Image from Warnes [9] reproduced with permission. Please remove Photo courtesy of Dr. W. D. Edwards, consultant in pathology, Mayo Clinic

Fig. 2

Four-chamber view on a transthoracic echocardiogram shows the intra-atrial baffles seen in a patient with D-loop TGA post atrial switch where baffles are used to restore physiological circulation. A An atrial baffle diverts blood from both vena cava across to the mitral valve and LV (blue arrow is in the systemic venous baffle), which ejects blood to the PA. B The oxygenated pulmonary venous blood returns to the tricuspid valve and systemic RV (red arrow is in the pulmonary venous baffle), which ejects blood to the aorta. C Apical short-axis view on a transthoracic echocardiogram shows a dilated and hypertrophied systemic RV where the interventricular septum bulges into the “banana” shaped—a finding expected in a patient with systemic RV post atrial switch repair

Fig. 3

Pathophysiological pathways of systemic right ventricular (RV) dysfunction from Winter [24]. The pathophysiology of systemic RV dysfunction is multifactorial and includes arrhythmias, tricuspid valve regurgitation, myocar-dial fibrosis, and myocardial ischemia. Image from Winter [24] reproduced with permission

Fig. 4

Pathologic specimen cut in the 4-chamber plane from a patient with Ebstein anomaly from Warnes [9]. The tricuspid valve is displaced markedly inferiorly, and the right ventricular wall is extremely thin. Image from Warnes [9] reproduced with permission. Please remove Photo courtesy of Dr. W. D. Edwards, consultant in pathology, Mayo Clinic