Tricuspid valve regurgitation (TVR) occurs when the valve separating the two chambers on the right side of the heart does not close completely. The tricuspid valve acts as a one-way door between the upper right chamber, the right atrium, and the lower right chamber, the right ventricle. When the right ventricle contracts to push blood toward the lungs, the faulty valve allows some blood to leak backward into the right atrium. This backward flow, or regurgitation, forces the right ventricle to work harder to move the necessary volume of blood forward.
Prevalence and Classification of Tricuspid Regurgitation
A minor, or trace, amount of tricuspid regurgitation is common, present in an estimated 75% to 85% of the general adult population when examined by echocardiogram. This slight backflow is often considered a benign physiological occurrence that typically causes no symptoms and does not require intervention. The prevalence of more clinically significant cases, classified as moderate or severe TVR, is much lower, affecting roughly 3% to 6% of the general population.
This rate rises considerably in specific groups, reaching up to 7% in individuals over 75 years old. It is also far more frequent in people with existing heart conditions; for example, in patients with heart failure, the prevalence of moderate-to-severe TVR can range from 10% to 23%. TVR is primarily classified into two types based on its cause, which determines its prevalence and mechanism.
The vast majority of clinically significant cases fall under Secondary (or Functional) TVR, accounting for approximately 90% of all diagnoses. In this common type, the valve leaflets themselves are structurally normal, but the right heart chambers have enlarged. This enlargement causes the valve ring (annulus) to stretch and prevents the leaflets from meeting properly. Conversely, Primary (or Organic) TVR is less common and results from direct abnormality or damage to the valve leaflets or supporting structures.
Underlying Causes and Contributing Risk Factors
Secondary tricuspid regurgitation is most often a consequence of conditions that increase pressure or volume on the right side of the heart, leading to the stretching of the right ventricle and the tricuspid annulus. The most frequent cause is high blood pressure in the lungs, known as pulmonary hypertension, which forces the right ventricle to generate higher pressures to pump blood. Left-sided heart failure, such as that caused by diseases of the mitral or aortic valves, can also indirectly lead to TVR by causing blood to back up into the lungs and increasing the workload on the right ventricle.
Primary TVR, though less common, is caused by specific damage to the valve itself. Infective endocarditis, a serious infection of the heart lining and valves often seen in people who use intravenous drugs, is a significant cause. Congenital heart defects, such as Ebstein anomaly where the valve is malformed and positioned lower than normal, are also a direct cause. Other risk factors include a history of rheumatic fever, chest trauma, and the placement of pacemaker or defibrillator leads that traverse the valve, potentially interfering with leaflet movement.
Recognizing Physical Symptoms and Diagnosis
In its mildest forms, tricuspid regurgitation typically does not produce noticeable symptoms, and the condition may only be discovered incidentally. When the regurgitation becomes moderate or severe, the backward flow of blood creates congestion in the veins leading to the right atrium, which can result in visible physical manifestations. Common signs relate to the systemic backup of fluid, including peripheral edema, which is swelling that accumulates in the legs, ankles, and feet.
Patients may also notice abdominal swelling, known as ascites, or discomfort in the upper right abdomen due to liver congestion. Other symptoms include a pulsing sensation in the neck veins, persistent fatigue, and shortness of breath, particularly during physical activity.
The primary diagnostic tool used to confirm the presence and severity of TVR is a transthoracic echocardiogram, an ultrasound of the heart. This non-invasive test allows physicians to visualize the heart’s structure and the backflow of blood through the valve using Doppler technology. The echocardiogram also provides crucial measurements of the right heart chambers, assessing for enlargement or dysfunction that indicates a secondary cause. While an electrocardiogram (ECG) or chest X-ray may show signs of an enlarged right heart, the echocardiogram remains the standard for accurate diagnosis and quantification of severity.
Medical and Surgical Management
The treatment strategy for tricuspid regurgitation is determined by its underlying cause, severity, and the presence of symptoms. For mild or asymptomatic TVR, a “watchful waiting” approach is often adopted, involving regular monitoring with echocardiography to track progression. Medical management focuses on alleviating the symptoms of fluid overload and addressing the root cause.
Diuretics, commonly referred to as water pills, are a mainstay of therapy, helping to manage systemic congestion, peripheral edema, and ascites by increasing the excretion of salt and water. Specific medications, such as aldosterone antagonists, may be used alongside other diuretics to reduce fluid retention and improve outcomes for patients with right-sided heart failure. Treating underlying conditions, such as optimizing therapy for pulmonary hypertension or left-sided heart disease, is a major component of managing secondary TVR.
Surgical or interventional treatments are considered when TVR is severe, causes significant symptoms, or is associated with progressive right ventricular enlargement or dysfunction. Valve repair, most commonly an annuloplasty where the stretched valve ring is tightened, is the preferred surgical option when technically feasible. Valve replacement with a biological or mechanical prosthetic valve is an alternative when the tricuspid valve structure is too damaged. Newer transcatheter procedures, which are less invasive, have emerged as options for patients at high surgical risk.