Right Ventricle

Overview

The right ventricle is one of the four chambers of the heart, responsible for pumping deoxygenated blood into the pulmonary circulation. It receives blood from the right atrium and propels it through the pulmonary valve into the pulmonary trunk, which directs the blood to the lungs for oxygenation. Structurally and functionally adapted to operate under low pressure, the right ventricle is essential in maintaining the continuous flow of blood through the lungs.

Location

The right ventricle occupies the anterior portion of the heart and forms most of the sternocostal surface and the inferior border. It lies:

• Anterior to the left ventricle

• Inferior to the right atrium

• Posterior to the sternum and costal cartilages

Its apex is directed toward the left and inferiorly, contributing to the lower margin of the heart but not forming the true apex, which is formed by the left ventricle.

Structure

The right ventricle has a crescent or triangular shape in cross-section and is divided into three functional components:

• Inlet portion: Includes the tricuspid valve and associated chordae tendineae and papillary muscles

• Trabeculated apical portion: Contains muscular ridges (trabeculae carneae), including the moderator band

• Outlet portion (infundibulum or conus arteriosus): Smooth-walled area leading to the pulmonary valve and trunk

The wall of the right ventricle is thinner than the left ventricle (about 3–5 mm) due to its operation under lower pressure. The internal surface is lined by prominent trabeculae carneae that aid in efficient contraction.

Function

The primary function of the right ventricle is to:

• Receive deoxygenated blood from the right atrium via the tricuspid valve

• Propel blood into the pulmonary circulation through the pulmonary valve and trunk

It contracts during systole, generating the pressure needed to open the pulmonary valve and eject blood into the pulmonary arteries. This ensures proper oxygenation of blood in the lungs.

Physiological Role(s)

The right ventricle plays several key physiological roles:

• Maintains pulmonary circulation: Supplies continuous blood flow to the lungs for gas exchange

• Regulates venous return: Ensures systemic venous blood is cleared efficiently to prevent congestion

• Supports ventricular interdependence: Its motion and pressure changes influence left ventricular filling and function (via the interventricular septum and pericardial constraint)

• Responds to volume and pressure changes: The right ventricle adapts more readily to volume overload than to pressure overload

Clinical Significance

The right ventricle is involved in numerous cardiovascular conditions, many of which can severely impact circulatory dynamics:

• Right Ventricular Failure: Can result from left heart failure, pulmonary hypertension, or primary right-sided disease (e.g., tricuspid regurgitation). Leads to systemic venous congestion, hepatomegaly, and peripheral edema.

• Pulmonary Hypertension: Increased afterload leads to right ventricular hypertrophy and eventual dilation and failure.

• Right Ventricular Infarction: Usually associated with inferior myocardial infarctions involving the right coronary artery. Presents with hypotension and elevated jugular venous pressure but clear lungs.

• Congenital Defects: Tetralogy of Fallot, pulmonary valve atresia, and double outlet right ventricle are conditions involving abnormal development or structure of the right ventricle.

• Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC): A rare inherited disease involving fibrofatty replacement of RV myocardium, causing arrhythmias and sudden cardiac death, especially in athletes.

• Tricuspid Valve Disease: As the valve lies at the inlet of the right ventricle, its dysfunction (e.g., tricuspid regurgitation) directly affects RV workload and efficiency.

• Imaging and Evaluation: Echocardiography, cardiac MRI, and right heart catheterization are key tools for assessing right ventricular size, function, and pressure dynamics.

Proper function of the right ventricle is essential for balanced circulation between the pulmonary and systemic circuits. Its dysfunction often presents subtly but can rapidly lead to hemodynamic compromise and multi-organ effects if left untreated.