USMLE: Heart Murmurs

Systolic Heart Sounds

Aortic Stenosis

Pulmonic Stenosis

Mitral Regurgitation

Tricuspid Regurgitation

VSD

Mitral Valve Prolapse (MVP)

S1

Mitral & Tricuspid Closure

S2

Aortic & Pulmonary Closure

S3

Rapid ventricular filling.

Early diastole!

*Mitral Regurgitation

Heart Failure

Dilated ventricles*

• Normal in kids/pregnant women.

S4

Late diastole ➡️ Atrial kick = Atria contracting against a stiff LV wall

High atrial pressure ➡️ Increase in LV End-Diastolic pressure causes blood to back uo into the left atrium & pulmonary veins.

Left Ventrucular Hypertrophy

Diastolic Heart Sounds

Aortic Regurgitation

Pulmonic Regurgitation

Mitral Stenosis

Tricuspid Stenosis

Mitral Regurgitation

SYSTOLIC

-Holosystolic, high pitched, "blowing"

-Loudest at apex

-Radiates to axilla

-Louder with squatting, hand grip (increased TPR) 👊

Tricuspid Regurgitation

SYSTOLIC

-Holosystolic, high pitched, "blowing"

-Loudest at tricuspid area

-Radiates to right sternal border

⚠️*Louder with inspiration* (increased RA return)

Aortic Stenosis

SYSTOLIC

-Crescendo-decrescendo

-Loudest at heart base

-Radiates to carotids

-"Pulsus parvus et tardus": weak pulses with delayed peak

-Complications: *S*yncope, *A*ngina, *D*yspnea (*SAD*)

- Loudest with rapid squatting (⬆️ preload)

VSD

SYSTOLIC

-Holosystolic, harsh at left lower sternal border.

-Loudest at *tricuspid area*

-Louder with hand grip 👊 (increased afterload)

ASD

Fixed splitting of the 2nd heart sound.

Common in Down Syndrome

Mitral Valve Prolapse

SYSTOLIC

-*Midsystolic click*

-Late systolic crescendo

-Loudest at apex

-Louder and earlier with *standing or Valsalva* (decrease venous return)

Common in Marfan & Ehlers-Dalos syndromes.

Aortic Regurgitation

DIASTOLIC

-Early diastole decrescendo

-High pitched "blowing"

-Louder with hand grip 👊(increased TPR)

-Wide pulse pressure ➡️ bounding pulses, head bobbing

Bicuspid Aortic Valve

-Aortic ejection sound

-Early systolic

-High-frequency click heard over the right 2nd interspace.

Increased risk for stenosis, insufficiency, and infection.

Common in *Turner Syndrome*... Along with Coarctation.

Mitral Stenosis

DIASTOLIC

-*Opening snap*

-Late-mid, low-pitched, rumbling, diastolic murmur

-Louder with *expiration* (increased LA return)

-Increased severity with decreased S2 to opening snap interval

PDA

CONTINUOUS

-"Machine-like"

-Loudest at *infraclavicular area*

-Loudest at S2

-Systole & Diastole

Common in premature infants, especially those with RDS.

Inspiration

↑ Intensity of *right heart sounds* (tricuspid regurgitation)

↑ Venous return to the right heart

↓ Venous return to the left heart

Valsalva and standing up

↓ Preload & ↓ Afterload

↓ Intensity of most murmurs (↓ blood flow through stenotic/regurgitant valves)

⚠️ *↑ Intensity of hypertrophic cardiomyopathy murmur*

⚠️ MVP: *Earlier* onset of click/murmur

Hand grip

↑ Afterload

⚠️ ↑ intensity of *MR, AR, & VSD* murmurs (↑ Left ventricle and aortic pressure)

↓ Intensity of hypertrophic cardiomyopathy murmurs

MVP: Later onset of click/murmur

Rapid squatting

↑ Preload & ↑ Afterload

⚠️ *↑ Intensity of Aortic Stenosis murmur* (↑ blood flow through stenotic/regurgitant valves)

↓ Intensity of hypertrophic cardiomyopathy murmur

MVP: later onset of click/murmur