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

Eccentric left ventricular hypertrophy (LVH) occurs when there is an increase in the volume of blood filling the left ventricle (dilatation), typically in response to volume overload. This type of hypertrophy is characterized by an increase in chamber volume rather than wall thickness.

In the context of conditions leading to eccentric LVH, hypertension primarily leads to concentric LVH due to increased pressure overload, where the heart muscle thickens to manage the increased workload. Thus, where hypertension does not directly lead to eccentric LVH, it is not the accurate choice in this question.

Atrial septal defect (ASD) can result in volume overload of the left ventricle due to left-to-right shunting of blood. This increased return of blood to the left atrium and subsequently to the left ventricle can cause eccentric hypertrophy.

Pericardial effusion typically does not lead to eccentric LVH; instead, it can impair diastolic filling and may lead to other types of cardiac stress rather than overload.

Pulmonary embolism can lead to right heart strain or failure but typically does not involve changes in the left ventricle in terms of hypertrophy features.

Thus, atrial septal defect is