**Question:** The systolic ejection murmur in hyperopic obstructive cardiomyopathy is diminished when a patient-

A. At rest
B. After exercise
C. With deep breathing
D. In the left lateral decubitus position

**Core Concept:** Systolic ejection murmur is aocardiogenic murmur resulting from the increased peripheral resistance and decreased cardiac output in patients with hyperopic obstructive cardiomyopathy. This condition is characterized by the inability of the heart to fill adequately due to left ventricular obstruction, leading to reduced cardiac output and elevated peripheral resistance.

**Why the Correct Answer is Right:** In hyperopic obstructive cardiomyopathy, the systolic ejection murmur is diminished primarily due to the reduced cardiac output. When a patient is at rest, their cardiac output is generally lower than during exercise or deep breathing. Exercise increases cardiac output by augmenting heart rate and stroke volume, which would typically result in a more pronounced systolic ejection murmur in this context. In the left lateral decubitus position, the heart can be placed under slight strain, which might be expected to result in a more prominent systolic ejection murmur. However, the primary focus in hyperopic obstructive cardiomyopathy is the reduced cardiac output, which again results in a diminished systolic ejection murmur. This is in contrast to deep breathing, which is known to increase the cardiac output and would be expected to enhance the systolic ejection murmur.

**Why Each Wrong Option is Incorrect:**

A. At rest: Although resting cardiac output is generally lower, the primary focus of the question is on the systolic ejection murmur, which is reduced due to cardiac output decrease.

B. After exercise: Exercise increases cardiac output, which would not lead to a diminished systolic ejection murmur in hyperopic obstructive cardiomyopathy. In fact, it would be expected to enhance the murmur.

C. With deep breathing: Similar to exercise, deep breathing increases cardiac output, which contradicts the expected reduction in systolic ejection murmur.

D. In the left lateral decubitus position: Although placing the heart under slight strain might be expected to increase the systolic ejection murmur, the primary focus of the question is on the reduced cardiac output, which is responsible for the diminished murmur.

**Clinical Pearl:** In hyperopic obstructive cardiomyopathy, the primary clinical sign to focus on is the systolic ejection murmur, which is diminished due to decreased cardiac output. This information is crucial in differential diagnosis, as the reduced murmur in this context would aid in distinguishing between various cardiac pathologies and confirming the diagnosis of hyperopic obstructive cardiomyopathy, which is a type of cardiomyopathy characterized by left ventricular dysfunction and increased left ventricular wall tension (hyperopic). Clinical pearls such as this can help guide clinical decision-making and aid in accurate diagnosis and treatment.