Carcinoid Syndrome Cardiac Valve Involvement

Carcinoid syndrome is characterized by the release of vasoactive substances, such as serotonin, from neuroendocrine tumors. These substances circulate in the bloodstream and can affect various organs, including the heart.

Understanding Cardiac Impact

The cardiac manifestations of carcinoid syndrome predominantly involve the right-sided heart valves. This is because the vasoactive substances released into the portal circulation are typically metabolized by the lungs before reaching the systemic circulation.

• Substances reaching the right heart can lead to plaque-like fibrous thickening and retraction of the valve leaflets.
• This process primarily affects valves exposed to the higher concentration of these substances.

Most Affected Valve

The Tricuspid valve is the most commonly affected valve in carcinoid syndrome. Its location between the right atrium and the right ventricle means it is directly exposed to the circulating vasoactive substances from the tumor.

While the Pulmonary valve can also be affected due to its position downstream in the right ventricular outflow tract, the Tricuspid valve involvement is more frequent and often more severe.

Left-sided valves (Aortic and Mitral) are much less commonly affected, as the lungs effectively filter out a significant portion of the harmful substances before they reach the left side of the heart.

Therefore, the Tricuspid valve is identified as the most common valve involved in Carcinoid syndrome.