9. Auscultation of heart – sounds and murmurs

Steps for Auscultation:

1. Quiet Environment:

• Ensure the room is quiet to hear heart sounds clearly.
• Have the patient in a relaxed, supine position.

2. Stethoscope Use:

• Diaphragm: Use for high-pitched sounds (e.g., S1, S2, murmurs).
• Bell: Use for low-pitched sounds (e.g., S3, S4, some murmurs).

3. Auscultation Areas:

• Aortic Valve: 2nd ICS, Right Sternal Border (RSB).
• Pulmonary Valve: 2nd ICS, Left Sternal Border (LSB).
• Tricuspid Valve: 4th ICS, Left Sternal Border (LSB).
• Mitral Valve (Apex): 5th ICS, Midclavicular Line (MCL).

4. Heart Sounds Identification:

• S1 (First Heart Sound):
• Occurs at the start of systole.
• Caused by the closure of the mitral and tricuspid valves.
• Loudest at the apex.
• S2 (Second Heart Sound):
• Occurs at the end of systole, start of diastole.

• Caused by the closure of the aortic and pulmonary valves.
• Loudest at the base of the heart (2nd ICS, RSB).
• S3 (Third Heart Sound):
• Occurs early in diastole (after S2).
• Associated with heart failure, increased ventricular filling pressure.
• Best heard at the apex with the bell.
• S4 (Fourth Heart Sound):
• Occurs late in diastole (before S1).
• Associated with stiff ventricles (e.g., left ventricular hypertrophy).
• Best heard at the apex with the bell.

5. Detecting Murmurs:

• Systolic Murmurs: Occur between S1 and S2.
• Example causes: Aortic stenosis, mitral regurgitation.
• Diastolic Murmurs: Occur after S2.
• Example causes: Aortic regurgitation, mitral stenosis.

6. Patient Positioning to Enhance Murmur Detection:

• Left Lateral Position:
• Helps better hear mitral stenosis (use the bell at the apex).
• Sitting Forward, Exhale:
• Best for hearing aortic regurgitation (use the diaphragm at the left sternal border).