Which of the following diseases is appropriately treated with combined heart-lung transplantation?
**Core Concept**
Combined heart-lung transplantation is a surgical procedure that involves transplanting both the heart and lungs from a donor to a recipient. This is typically required for conditions where both organs are severely damaged, and individual transplantation would not be sufficient to restore normal function.
**Why the Correct Answer is Right**
The primary indication for combined heart-lung transplantation is idiopathic pulmonary arterial hypertension (IPAH) with right ventricular failure. In IPAH, the small pulmonary arteries become stiff and narrow, leading to increased resistance against which the right ventricle must pump blood. Over time, the right ventricle becomes hypertrophied and eventually fails, necessitating a combined transplant to restore normal cardiovascular and respiratory function.
**Why Each Wrong Option is Incorrect**
**Option A:** Primary pulmonary hypertension is not the same as IPAH; it is a broader term that encompasses multiple causes of pulmonary hypertension. While some cases of primary pulmonary hypertension may require combined transplantation, the term is too broad to be the correct answer.
**Option B:** Severe chronic obstructive pulmonary disease (COPD) may require lung transplantation, but it does not typically require combined heart-lung transplantation.
**Option C:** Idiopathic cardiomyopathy may require heart transplantation, but it does not typically require combined heart-lung transplantation.
**Clinical Pearl / High-Yield Fact**
In IPAH, the hallmark histopathological finding is plexiform arteriopathy, characterized by abnormal proliferation of endothelial cells and thickening of the pulmonary arterial walls, leading to increased vascular resistance and right ventricular failure.
**Correct Answer: C. Idiopathic pulmonary arterial hypertension with right ventricular failure.**