Which cardiac anomaly is characterized by a thickened tricuspid valve and regurgitation?

The presence of a thickened tricuspid valve along with regurgitation is a hallmark of carcinoid heart disease. This condition arises as a result of a neuroendocrine tumor, often originating in the gastrointestinal tract, that secretes substances, particularly serotonin, leading to fibrotic changes in heart valves. The involvement of the tricuspid valve is particularly notable in this condition, as the excess serotonin causes the valve to become thickened and leads to functional impairment, resulting in regurgitation.

The distinct nature of carcinoid heart disease is characterized by the specific involvement of the right-sided heart structures, which is not typically seen in the other listed cardiac anomalies. For example, ventricular septal defects usually manifest as left-to-right shunting and do not specifically cause tricuspid valve thickening. Patent ductus arteriosus involves an abnormal connection between the aorta and pulmonary artery, and mitral valve prolapse is primarily associated with the mitral valve itself, not the tricuspid.

Understanding the specific pathology of carcinoid heart disease helps to clarify why the thickening of the tricuspid valve and subsequent regurgitation are characteristic features of this anomaly.