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

What distinguishes Eccentric LVH from Concentric LVH?

1. Increased left ventricular wall thickness

2. Left atrial enlargement

3. Normal ejection fraction

4. Reduced chamber size

The correct answer is: Left atrial enlargement

Eccentric LVH and Concentric LVH are both terms used to describe hypertrophy, or thickening, of the left ventricular wall. However, they refer to different types or patterns of hypertrophy. Concentric LVH is characterized by increased wall thickness and a decrease in left ventricular chamber size, while Eccentric LVH is characterized by increased wall thickness and an enlargement of the left atrium. Therefore, option B, Left atrial enlargement, is the most appropriate distinguishing feature between the two types of LVH. Option A is incorrect because both types of LVH involve increased wall thickness. Option C is incorrect because the ejection fraction can be normal or reduced in both types of LVH. Option D is incorrect because the chamber size is reduced in Concentric LVH, but not in Eccentric LVH.