MC cause of death in adult with PDA is-
**Core Concept**
The patent ductus arteriosus (PDA) is a congenital heart defect characterized by the persistent patency of the ductus arteriosus, a vascular structure connecting the aorta and pulmonary artery in the fetal circulation. The clinical presentation and management of PDA depend on its size, location, and associated cardiac anomalies.
**Why the Correct Answer is Right**
The most common cause of death in adults with PDA is **thromboembolic events**. This is due to the formation of blood clots in the ductus arteriosus, which can lead to pulmonary embolism or systemic embolism. The risk of thromboembolism is increased in adults with PDA, particularly those with larger ducts, due to the abnormal flow of blood through the ductus arteriosus. The high flow and turbulence in the ductus arteriosus create an environment conducive to thrombus formation.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because while heart failure can occur in adults with PDA, it is not the most common cause of death. Heart failure is more likely to be a consequence of prolonged exposure to high flow and volume overload rather than a direct cause of mortality.
**Option B:** This option is incorrect because arrhythmias can occur in adults with PDA, but they are not the most common cause of death. Arrhythmias may be precipitated by the abnormal flow and pressure patterns in the ductus arteriosus, but they are generally not life-threatening in the absence of other complications.
**Option C:** This option is incorrect because while infection can occur in adults with PDA, it is not the most common cause of death. Infection of the ductus arteriosus (arteritis) can occur, particularly in individuals with a history of endocarditis or other infections.
**Clinical Pearl / High-Yield Fact**
Adults with large PDA are at increased risk of thromboembolic events due to the abnormal flow and turbulence in the ductus arteriosus. This risk is further increased in individuals with a history of smoking, hypertension, or other cardiovascular risk factors.
**Correct Answer:** C.