How to Chart a Murmur Loudest Under the Left Pectoral Muscle
Document this murmur as "best heard at the left ventricular apex" or "loudest at the apex" in your physical examination note. The area beneath the left pectoral muscle corresponds anatomically to the cardiac apex, which is the standard terminology used in cardiovascular examination documentation.
Proper Documentation Structure
When charting this finding, include these specific elements in your physical exam:
Location and Radiation
- Primary location: "Apex" or "left ventricular apex" (this is beneath the left pectoral muscle)
- Radiation pattern: Note if it radiates to the axilla, left sternal border, or base
- The distribution pattern helps differentiate pathology—an "apical-base" pattern suggests aortic valve disease, while a "broad apical" pattern indicates mitral regurgitation 1
Essential Descriptors to Include
Timing in cardiac cycle:
- Systolic (holosystolic, early systolic, midsystolic, or late systolic)
- Diastolic (early, mid, or presystolic)
- Continuous
Intensity: Grade 1-6/6 using the Levine scale
Quality: Harsh, blowing, rumbling, musical, or vibratory
Dynamic maneuvers: Document how the murmur changes with:
- Respiration (left-sided murmurs typically louder with expiration) 2
- Position changes (standing vs. squatting)
- Valsalva maneuver
Common Pathologies at the Apex
A murmur loudest at the apex typically indicates:
Mitral regurgitation - Holosystolic, blowing quality, radiates to axilla 3
Mitral stenosis - Middiastolic rumbling murmur with opening snap 2
Mitral valve prolapse - Late systolic murmur, often with midsystolic click 3
Austin-Flint murmur - Low-pitched rumbling diastolic murmur in severe chronic aortic regurgitation 2
Critical Documentation Pitfall
Never use vague anatomical descriptions like "under the left pectoral muscle" in formal medical documentation. This lacks the precision needed for clinical decision-making and communication with consultants. Standard cardiac examination terminology uses specific landmarks: apex, left sternal border (upper, mid, lower), right upper sternal border, and base.
Example Documentation
"Cardiovascular: Grade 3/6 holosystolic murmur loudest at the apex, radiating to the axilla. Murmur intensity increases with expiration and handgrip maneuver. No S3 or S4 appreciated."
This standardized approach ensures clear communication with cardiologists and provides a baseline for serial examinations 4.