Tricuspid valve regurgitation (TR) is a heart condition where the valve separating the right atrium (upper chamber) and the right ventricle (lower chamber) does not close completely. The tricuspid valve’s primary function is to act as a one-way door, ensuring that deoxygenated blood flows forward into the ventricle. Regurgitation occurs when this valve malfunctions, allowing blood to leak backward into the right atrium during the heart’s contraction phase. This backward flow, often referred to as a “leaky valve,” reduces the heart’s efficiency in moving blood toward the lungs for oxygenation.
The Mechanism of Tricuspid Valve Regurgitation
When the tricuspid valve fails to coapt fully, a portion of the blood intended for the lungs flows back into the right atrium during systole, the moment the right ventricle contracts. The right atrium then becomes overloaded with a mix of blood, increasing the volume and pressure within the chamber. This increased pressure subsequently transmits backward into the major veins that drain into it, leading to a condition known as systemic venous congestion. The right side of the heart struggles to manage this volume overload, which can cause the right ventricle to dilate, or enlarge. As the right ventricle and the surrounding ring of tissue, the tricuspid annulus, stretch, the valve leaflets are pulled apart, further worsening the leak.
Identifying the Underlying Causes
The causes of tricuspid regurgitation are broadly categorized into two types: primary and secondary, with secondary being far more common. Primary tricuspid regurgitation (also called organic) involves a direct problem with the valve’s structure, such as damage to the leaflets, the cords that support them, or the valve ring itself. Examples of primary causes include damage from infectious endocarditis, rheumatic fever, certain congenital defects like Ebstein’s anomaly, or injury from pacemaker wires.
Secondary tricuspid regurgitation (also called functional) accounts for the vast majority of cases and occurs when the valve itself is structurally normal but malfunctions due to an underlying condition. This functional failure typically results from the dilation or enlargement of the right ventricle and tricuspid annulus. Conditions that cause this enlargement often involve high pressure on the right side of the heart, such as left-sided heart failure or pulmonary hypertension.
Recognizing the Signs and Symptoms
The physical manifestations of tricuspid regurgitation are directly related to the systemic venous congestion caused by the backward flow of blood. As pressure builds up in the veins, fluid is pushed out of the blood vessels and into surrounding tissues.
Fluid Retention
This fluid retention often presents as peripheral edema, which is noticeable swelling in the legs, ankles, and feet. Fluid accumulation can also occur higher up in the body, leading to ascites, which is the buildup of fluid within the abdominal cavity.
Other Effects
The liver can become congested and enlarged due to the back pressure from the veins, causing a feeling of fullness or discomfort in the upper right abdomen. Severe regurgitation can also cause jugular venous distention, which is a visible, active pulsing or throbbing in the neck veins as the high pressure in the right atrium is transmitted. Patients may also experience general fatigue and weakness because the heart is inefficiently pumping blood.
Diagnosis and Management Approaches
The definitive tool for confirming a diagnosis of tricuspid regurgitation and determining its severity is the echocardiogram, a non-invasive ultrasound of the heart. This imaging test allows physicians to visualize the tricuspid valve’s structure, measure the extent of the blood leak, and assess the size and function of the right-sided heart chambers. A physician may also detect the condition during a physical examination by listening for a characteristic heart murmur, a whooshing sound caused by the turbulent backward blood flow.
Management strategies are tailored to the cause and severity of the regurgitation, beginning with medical therapy focused on symptom control. The main medical treatment involves the use of diuretics, often called “water pills,” which help the body excrete excess fluid and reduce the systemic venous congestion. By reducing the overall fluid volume, diuretics alleviate symptoms like swelling and abdominal bloating.
For severe cases, more aggressive intervention may be necessary. Surgical options include tricuspid valve repair, such as annuloplasty, which tightens the stretched valve ring, or full valve replacement with a prosthetic valve. Newer, less invasive transcatheter procedures are also emerging, offering repair or replacement options for high-risk patients who may not tolerate open-heart surgery.