Heart failure occurs when the heart muscle cannot pump enough blood to meet the body’s needs. The heart functions as two connected pumps: the left side handles oxygenated blood for the body, and the right side manages deoxygenated blood for the lungs. Right Heart Failure (RHF) involves a problem with the pump that receives blood from the body’s circulation and moves it forward to the lungs. This inability to effectively push blood into the pulmonary system causes distinct physiological consequences.
Defining Right Heart Failure
The right side of the heart is composed of the right atrium and the right ventricle (RV). The right atrium collects deoxygenated blood returning from the body through the vena cavae. The RV then pumps this blood into the pulmonary artery toward the lungs for oxygenation. RHF is defined by the right ventricle’s impaired ability to perform this pumping function effectively.
The anatomy of the right ventricle differs significantly from the muscular left ventricle, making it highly sensitive to changes in resistance. The RV is adapted to pump against the low-pressure pulmonary circulation. RHF is often characterized by systolic dysfunction (impaired contraction), although issues with filling (diastolic dysfunction) can also be present. This impaired function means the right ventricle cannot overcome the pressure in the lungs, causing blood flow to slow down and back up.
Conditions That Strain the Right Ventricle
The primary conditions leading to RHF involve an increased workload on the right ventricle, categorized as either pressure or volume overload. The most common cause of RHF is Left-Sided Heart Failure (LHF). When the left ventricle fails, blood backs up into the lungs, causing pressure in the pulmonary blood vessels to rise. This increased pressure (pulmonary hypertension) eventually overwhelms the right ventricle, which is not built to pump against high resistance.
Other conditions directly increase resistance in the lung’s blood vessels, placing a direct strain on the RV. Pulmonary hypertension (abnormally high blood pressure in the lung arteries) is a major primary cause of RHF. Chronic lung diseases, such as Chronic Obstructive Pulmonary Disease (COPD), also cause pulmonary blood vessels to narrow or be destroyed. This leads to a form of RHF called Cor Pulmonale, where the right ventricle works harder against the resistance until it weakens and fails.
The Pathway of Systemic Fluid Congestion
When the right ventricle loses its pumping power, it cannot efficiently move blood from the body into the lungs. This failure results in a backward buildup of pressure that travels through the vena cavae and into the systemic circulation. Systemic venous congestion is the defining physiological consequence of RHF. The elevated pressure inside the veins pushes fluid out of the blood vessels and into the surrounding tissues and organs.
This fluid backup affects internal organs, especially the liver and the gastrointestinal tract. The liver can become engorged (hepatic congestion) because returning blood cannot easily enter the right atrium, impairing liver function and causing discomfort. Congestion in the gastrointestinal tract’s veins can reduce blood flow to the gut lining, causing hypoxia and acidosis. This contributes to digestive symptoms like nausea, loss of appetite, and bloating. The high pressure also affects the kidneys, exacerbating fluid retention and worsening systemic congestion.
Identifying the Physical Manifestations
The systemic fluid backup caused by RHF results in several observable physical signs. Peripheral edema is the most common manifestation, appearing as swelling, particularly in the feet, ankles, and legs. This occurs because high venous pressure forces fluid from the capillaries into the surrounding tissues, pooling in the lower extremities due to gravity.
Another significant sign is Jugular Venous Distension (JVD), the visible swelling of the neck veins. The jugular veins drain directly into the superior vena cava, and their distension reflects the elevated pressure within the right atrium. Fluid can also accumulate in the abdomen, a condition called ascites, due to congestion in the abdominal veins. Patients often experience rapid weight gain from this excess fluid retention, alongside fatigue because the failing heart cannot supply enough blood to the muscles.