Anatomy, echocardiography, and normal right ventricular dimensions

Abstract

Often overlooked, and considered the poor relation of the left ventricle, there is increasing interest in the right ventricle particularly with regard to right ventricular failure. Right ventricular function may be impaired as a result of pressure or volume overload, often secondary to right heart valve or muscle pathology. Coronary artery disease may also lead to right ventricular dysfunction when the right coronary artery is occluded. In congenital heart malformations the right ventricle may also be affected, particularly in conditions that have the right ventricle supporting the systemic circulation or it becomes the sole pumping chamber following univentricular repair at surgery. Finally, right-to-left shunting may lead to right ventricular dilatation. Imaging the right ventricle by echocardiography is challenging because of the very particular crescentic shape of the right ventricle wrapping around the left ventricle, but it is important and ought to be part of the standard echocardiographic examination of the heart. To help understand cross sectional imaging of the right ventricle, we first review its location and its component parts, including the tricuspid and pulmonary valves, before discussing echo-anatomic correlations. The right ventricle in the normal heart is the most anteriorly situated cardiac chamber since it is located immediately behind the sternum. It also marks the inferior border of the cardiac silhouette. In contrast to the near conical shape of the left ventricle, the right ventricle is more triangular in shape when viewed from the front and it curves over the left ventricle. When seen from the apex, the right edge of the right ventricle is sharp, forming the acute margin of the heart. In cross section the cavity appears like a crescent. Thus, the curvature of the ventricular septum places the right ventricular outflow tract antero-cephalad to that of the left ventricle’s resulting in a characteristic “cross over” relationship …