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

Which of the following pathophysiological changes is a feature of Eccentric LVH?

1. Increased chamber stiffness

2. Reduced ventricular wall thickness

3. Ventricular hypertrophy with preserved ejection fraction

4. Ventricular hypertrophy with impaired diastolic function

The correct answer is: Reduced ventricular wall thickness

Eccentric left ventricular hypertrophy (LVH) is characterized by the dilation of the left ventricle alongside an increase in the size of the ventricular chamber. This type of hypertrophy typically occurs in response to volume overload conditions, such as valvular regurgitation or chronic hypertension, leading to an increase in the overall chamber size. The notion of reduced ventricular wall thickness is actually a misinterpretation of how eccentric LVH manifests; while it may appear that ventricular wall thickness is not as increased compared to concentric hypertrophy, the key feature is that the chamber itself becomes larger due to volume overload rather than a decrease in functional capability. Eccentric LVH allows for the maintenance of a normal ejection fraction since the myocardium is able to adapt well to the increased volume. The heart can still pump effectively despite the changes in size and wall structure. Additionally, preserved ejection fraction indicates that the heart is still functioning adequately during systole. Contrary to wall thickness being reduced, the condition does not necessarily correlate with impaired diastolic function; instead, in the earlier stages of eccentric LVH, diastolic function can remain relatively preserved. Overall, the main feature is the enlargement of the cavity, which characterizes this