Identifying cardiac auscultation murmurs & associated exam findings

Aortic regurgitation

Murmur -- early diastolic murmur
Exam findings -- hyperdynamic pulse, bounding or "water-hammer" peripheral pulses

Detailed explanations

blood regurgitates into the LV from the aorta --> even less blood in the aorta --> decreased DBP --> peripheral arteries "collapse". When the LV contracts the next time it has more blood to pump out -> increased stroke volume -> increased SBP -> peripheral arteries must accomodate this increased flow and pressure and they "expand". Net result "bounding" pulse

Aortic stenosis

Murmur --
Exam findings -- pulsus parvus et tardus (low amplitude and delayed upstroke)

Mitral regurgitation

Mitral stenosis

Apical diastolic rumble

Atrial septal defect

Murmur -- widening and fixed splitting of S2, may have midsystolic pulmonary flow murmur
Exam findings -- if large, tachypnea.

Details

ASD -> L to R shunting -> more blood in RA then RV -> delayed closure of pulmonic valve as more blood needs to pass through it -> wider S2. Inspiration and expiration have no effect on closure time for pulmonic valve now -> fixed S2.

Ventricular septal defect

Murmur -- holosystolic and at LLSB. Smaller VSDs produce louder/ more intense murmurs due to small hole creating greater turbulence as blood flows through. With increased L->R shunting there may be an apical diastolic murmur (as with mitral stenosis) as blood flows past the mitral valve. The L->R shunt causes increased RV pressure -> this pressure closes the pulmonic valve with greater force -> louder S2.

Coarctation of the Aorta

Exam findings -- HTN in upper limb, hypotension in lower limb. Absent/ delayed femoral pulses.

Tetralogy of Fallot

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pathology

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