Match each physical examination finding and its corresponding response to dynamic auscultatory maneuvers with the most likely underlying structural or valvular pathology.
- Harsh crescendo-decrescendo systolic murmur that becomes louder during the strain phase of the Valsalva maneuverHypertrophic obstructive cardiomyopathy
- Systolic ejection murmur at the right upper sternal border that becomes louder with rapid squatting and softer with standingSevere aortic valve stenosis
- Systolic murmur preceded by a mid-systolic click that moves closer to the first heart sound () upon standingMitral valve prolapse
- High-pitched, blowing, early diastolic murmur that becomes louder with sustained handgripAortic valve regurgitation
Answer
The physical examination findings map to their physiological responses: Valsalva increases HOCM murmurs by decreasing preload, squatting increases AS murmurs by increasing forward flow, standing moves the MVP click earlier by decreasing LV volume, and handgrip increases AR murmurs by elevating afterload.
Each structural defect responds to hemodynamic changes according to its underlying pathophysiology. Hypertrophic obstructive cardiomyopathy and mitral valve prolapse are primarily affected by left ventricular volume (worsening with decreased preload). Aortic stenosis depends on flow across the valve (worsening with increased preload/stroke volume). Aortic regurgitation is driven by the pressure gradient across the incompetent valve (worsening with increased afterload).
Step-by-Step Solution
Key Concept
Dynamic auscultation utilizes physiologic maneuvers (such as standing, squatting, handgrip, and Valsalva) to alter preload and afterload, helping to differentiate underlying structural and valvular heart defects based on predictable changes in murmur intensity and timing.