MC cause of morbidity and moality late in the course of mitral stenosis: March 2013
**Core Concept**
Mitral stenosis is a valvular heart disease characterized by the narrowing of the mitral valve orifice, leading to increased pressure and flow restriction in the left atrium. Late in the disease course, complications arise due to the prolonged elevation of left atrial pressure, resulting in various systemic and pulmonary manifestations.
**Why the Correct Answer is Right**
The most common cause of morbidity and mortality late in the course of mitral stenosis is pulmonary hypertension. This occurs as a result of the chronic elevation of left atrial pressure, which eventually leads to increased pressure in the pulmonary arteries. The increased pressure causes right ventricular hypertrophy, which can eventually lead to right heart failure and death. The pathophysiology is closely related to the increased resistance in the pulmonary vasculature, which can be assessed using echocardiography and right heart catheterization.
**Why Each Wrong Option is Incorrect**
**Option A:** Atrial fibrillation is a common complication of mitral stenosis, but it is not the most common cause of morbidity and mortality late in the disease course. While atrial fibrillation can lead to thromboembolic events and heart failure, pulmonary hypertension remains the most significant concern.
**Option B:** Left atrial enlargement is a hallmark of mitral stenosis, but it is not the primary cause of morbidity and mortality late in the disease course. Left atrial enlargement can lead to various complications, including arrhythmias and thromboembolic events, but pulmonary hypertension remains the more significant concern.
**Option C:** Mitral regurgitation is often seen in conjunction with mitral stenosis, but it is not the most common cause of morbidity and mortality late in the disease course. While mitral regurgitation can lead to heart failure, pulmonary hypertension remains the primary concern.
**Option D:** Sudden death is a potential complication of mitral stenosis, but it is not the most common cause of morbidity and mortality late in the disease course. Sudden death can occur due to various mechanisms, including pulmonary embolism and cardiac arrhythmias, but pulmonary hypertension remains the more significant concern.
**Clinical Pearl / High-Yield Fact**
Pulmonary hypertension is often a silent killer in patients with mitral stenosis, and early detection and treatment are crucial to prevent right heart failure and death. Echocardiography and right heart catheterization are essential diagnostic tools for assessing pulmonary hypertension in these patients.
**Correct Answer: C. Mitral regurgitation is often seen in conjunction with mitral stenosis, but it is not the most common cause of morbidity and mortality late in the disease course. While mitral regurgitation can lead to heart failure, pulmonary hypertension remains the primary concern.**