USMLE (United States Medical Licensing Examination) Step 1 Practice Exam

Which condition may lead to Eccentric LVH in individuals with chronic uncontrolled hypertension?

1. Atrial fibrillation

2. Diastolic dysfunction

3. Secondary polycythemia

4. Systolic heart failure

The correct answer is: Diastolic dysfunction

Eccentric left ventricular hypertrophy (LVH) is characterized by an increase in the left ventricular mass with a proportional increase in the chamber size, often resulting from volume overload. In the context of chronic uncontrolled hypertension, the heart undergoes adaptations that allow it to maintain effective circulation despite increased systemic vascular resistance. Diastolic dysfunction can occur as a consequence of prolonged hypertension, particularly when blood pressure is inadequately controlled. For example, over time, the heart may experience increased filling pressures, leading to changes in diastolic function. As the left ventricle struggles to fill normally, it may dilate (increase in chamber size) while also thickening its walls due to the demands of volume overload or pressure overload states. In cases of chronic hypertension, especially when systolic pressure is significantly elevated, the heart might also face increased ventricular load due to conditions like fluid retention or high cardiac output states, which become more pronounced in untreated or poorly managed hypertension. This interplay results in eccentric hypertrophy, where the heart adapts through an increase in both wall thickness and chamber size. The other conditions listed would not directly cause eccentric LVH in the same manner that diastolic dysfunction would. Atrial fibrillation typically results in atrial enlargement and irregular