Cardiac Examination III

What causes a murmur?

- turbulent blood flow

- can be due to valvular heart disease as well as "innocent" murmur

How are murmur sounds distinguished?

by pitch and longer duration

What are the classifications for a murmur?

- timing and duration (systole, diastole, or continuous)

- pitch (low frequency = bell, high frequency = diaphragm)

- intensity (grading scale)

- pattern

- quality

- location and radiation

- respiratory phase variations

Grade 1 (systolic murmur)

very faint, may not be heard in all positions

Grade 2 (systolic murmur)

quiet, but heard immediately after placing the stethoscope

Grade 3 (systolic murmur)

moderately loud

Grade 4 (systolic murmur)

loud, with palpable thrill

Grade 5 (systolic murmur)

very loud with thrill, may be heard when stethoscope is partly off the chest

Grade 6 (systolic murmur)

very loud, with thrill, may be heard without stethoscope on chest

Grade 1 (diastolic murmur)

barely audible

Grade 2 (diastolic murmur)

faint but immediately audible

Grade 3 (diastolic murmur)

easily heard

Grade 4 (diastolic murmur)

very loud

When do systolic murmurs occur?

during S1 and S2

Early systolic

early onset obscuring S1 but ending before S2

Midsystolic

onset after S1 and ends before S2

Late systolic

onset after S1 but ends obscuring S2

Holosystolic/Pansystolic

early onset obscuring S1 and ends obscuring S2

When do diastolic murmurs occur?

between S2 and S1

Early diastolic

early onset obscuring S2 and ending before S1

Mid diastolic

onset after S2 but ends before S1

Late diastolic

onset late in diastole, close to S2 and ends obscuring it

What is the most common type of murmur?

midsystolic (physiologic/innocent or pathological)

True or False: Holosystolic murmurs are always pathologic.

True

True or False: Diastolic murmurs are almost always pathologic.

True

What is the equation for cardiac output?

CO = HR x SV

Heart Rate (HR)

number of heartbeats per minute

Stroke Volume (SV)

the volume of blood ejected per beat, generally 60-90 mL/beat in healthy adults

Preload

the volume of blood filling the heart (end diastolic volume)

Contractility

the force of the heart muscle contraction

Afterload

the pressure the heart must overcome to eject blood

How does standing change preload?

Decreases preload (decreased peripheral resistance and decreased venous return to heart -> BP, SV, and volume of blood in LV decline)

How does squatting change preload?

Increases preload (increased peripheral resistance and increased venous return to heart -> BP, SV, and volume of blood in LV increase)

How is standing and squatting helpful?

helps to identify mitral valve prolapse and distinguish between hypertrophic cardiomyopathy and aortic stenosis

Valsalva

forcible exhalation increases intrathoracic pressure during strain phase

How does valsalva affect preload?

decreases preload

How is valsalva helpful?

helps to distinguish between hypertrophic cardiomyopathy and aortic stenosis

Isometric hand grip

increases blood volume in arms

How does isometric hand grip affect afterload and preload?

increases afterload; minimal to no increase in preload

How is isometric hand grip helpful?

helps to identify mitral regurgitation, pulmonic stenosis, ventricular septal defect, as well as aortic regurgitation and mitral stenosis through increasing murmur

How does positioning affect murmurs?

leaning forward = increases aortic murmurs

left lateral decubitus = increases mitral murmurs

What are murmurs that don't progress past the first 1/3 of systolic (early systolic murmurs) considered?

physiologic (and uncommon)

What causes midsystolic murmurs?

- innocent and physiologic

- aortic stenosis

- hypertrophic cardiomyopathy

- pulmonic stenosis

Innocent and physiologic murmurs (midsystolic murmurs)

- midsystolic, soft, no other associated heart sounds

Where are innocent and physiologic murmurs located? (midsystolic murmurs)

pulmonic region (most commonly)

How do innocent and physiologic murmurs change with hand grip/sitting? (midsystolic murmurs)

decrease in intensity

Innocent murmurs (midsystolic murmurs)

turbulent flow generated by ventricular ejection of blood

What population are innocent murmurs common in? (midsystolic murmurs)

children and young adults, no underlying valvular disease

Physiologic murmurs (midsystolic murmurs)

turbulence due to temporary increase in blood flow due to predisposing conditions

What conditions predispose one to a physiologic murmur? (midsystolic murmurs)

pregnancy, anemia, hyperthyroidism

What type of murmur is seen in aortic stenosis?

midsystolic/pathologic

Location of aortic stenosis murmur

right 2nd to 3rd intercostal space

Radiation of aortic stenosis murmur

neck/carotics (murmur is louder below the clavicle, though)

Pitch of aortic stenosis murmur

medium; crescendo-decrescendo may be higher at the apex

Quality of aortic stenosis murmur

harsh, may be more musical at apex

How is an aortic stenosis murmur best heard?

with the patient sitting and leaning forward

How does standing or Valsalva strain phase change an aortic stenosis murmur?

decreases murmur

How does squatting change an aortic stenosis murmur?

increases murmur

How does isometric hand grip change an aortic stenosis murmur?

decreases murmur

What is a hypertrophic cardiomyopathy murmur caused by?

mitral valve hitting against hypertrophied septum (not caused by turbulence)

What type of murmur is a hypertrophic cardiomyopathy murmur?

midsystolic/pathologic

Location of hypertrophic cardiomyopathy murmur

left lower sternal border (L 3rd/4th space)

Radiation of hypertrophic cardiomyopathy murmur

does not radiate to neck

Pitch of hypertrophic cardiomyopathy murmur

medium

Quality of hypertrophic cardiomyopathy murmur

harsh

How does standing or valsalva strain phase change a hypertrophic cardiomyopathy murmur?

increases murmur

How does squatting change a hypertrophic cardiomyopathy murmur?

decreases murmur

What type of murmur occurs in pulmonic stenosis?

midsystolic/pathologic

Location of pulmonic stenosis murmur

left 2nd and 3rd intercostal space

Radiation of pulmonic stenosis murmur

left shoulder and neck (if loud)

Pitch of pulmonic stenosis murmur

crescendo-decrescendo

Quality of pulmonic stenosis murmur

harsh

What is a pulmonic stenosis murmur often heard with?

ejection click and fixed split S2

How does isometric hand grip change a pulmonic stenosis murmur?

increases murmur

What causes late systolic murmurs?

- mitral valve prolapse

- pulmonary valve prolapse

Describe a mitral valve prolapse murmur.

Begins with a midsystolic click extending to late systole

What is the most common extra heart sound?

midsystolic click

Where is a mitral valve prolapse murmur best heard?

best heard at apex/left lower sternal border

Describe the pitch (and shape) of mitral valve prolapse murmur

high-pitched midsystolic click, followed by late systolic murmur from mitral regurgitation crescendos to S2

How does squatting change a mitral valve prolapse murmur?

delays click due to increased venous return and murmur shortens, decreases the prolapse

How does standing and valsalva strain phase change a mitral valve prolapse murmur?

click moves earlier in systole, murmur lengthens, increases the prolapse

When is a pulmonary valve prolapse murmur heard?

late systolic

Where is pulmonary valve prolapse murmur best heard?

left 2nd ICS

Describe the shape and quality of a pulmonary valve prolapse murmur

crescendo-decrescendo, harsh

What is a pulmonary valve prolapse murmur associated with?

S2 split

How does a pulmonary valve prolapse murmur change with deep inspiration?

increased intensity

What disorder is pulmonary valve prolapse often seen in?

congenital disorder (tet)

What causes holosystolic/pansystolic murmurs?

- mitral regurgitation

- tricuspid regurgitation

- ventricular septal defect

What type of murmur is seen in mitral regurgitation?

holosystolic/pathologic

Location of mitral regurgitation murmur

apex

Radiation of mitral regurgitation murmur

left axilla, less often left sternal border

Pitch of mitral regurgitation murmur

high-pitched

Qualtity of mitral regurgitation murmur

harsh, blowing, holosystolic

How does a mitral regurgitation murmur change with isometric hand grip?

increases murmur

How does a mitral regurgitation murmur change with inspiration?

does not vary with inspiration

What type of murmur is a tricuspid regurgitation murmur?

holosystolic/pathologic

Location of tricuspid regurgitation murmur

left lower sternal border

Radiation of tricuspid regurgitation murmur

epigastrium

Pitch of tricuspid regurgitation murmur

medium

Quality of tricuspid regurgitation murmur

blowing, holosystolic