How does a Valsalva maneuver affect HOCM sounds?

• A. The sounds become quieter
• B. The sounds become louder
• C. The condition worsens
• D. There is no effect on sounds

Answer: (B)

The Valsalva maneuver is a technique that involves forceful exhalation against a closed airway, typically achieved by closing one's mouth and nose and attempting to breathe out. This maneuver affects intrathoracic pressure and venous return to the heart.

In the case of hypertrophic obstructive cardiomyopathy (HOCM), the classic findings during auscultation include a systolic ejection murmur caused by left ventricular outflow tract obstruction due to the hypertrophied myocardial tissue. When a patient performs the Valsalva maneuver, the decreased venous return leads to a drop in left ventricular filling and subsequent left ventricular volume. As a result, less blood enters the left ventricle, leading to an increased gradient of obstruction in the outflow tract.

This increase in the outflow tract obstruction allows the murmur associated with HOCM to become more pronounced or louder. The mechanism behind this involves the relative decrease in left ventricular volume to the hypertrophied muscle mass, enhancing the turbulence of blood flow as it passes through a narrowed outflow tract. Therefore, during the Valsalva maneuver, the sounds become louder, which is a characteristic finding in patients with HOCM.