Murmurs and Myocardial Sounds…Making Sense of the Madness

Sara G. Tariq, M.D.

August, 2012

Goals

 Know how we classify murmurs • Systolic    Crescendo-decrescendo • Aortic stenosis, pulmonic stenosis, or “innocent” murmur Holosystolic • Mitral regurg, tricuspid regurg or VSD Late Systolic - MVP • Diastolic   Aortic regurgitation, pulmonic regurgitation Stenosis of mitral or tricuspid • Both  Patent Ductus Arteriosus

Goals

  Know the significance of rubs Know the significance of extra sounds • Split S2 (varies vs split) • S3 • S4

What are murmurs?

   Sounds Murmurs exist because of turbulent blood flow or increased velocity of blood flow across an orifice (a valve) Usually 3 different kinds of sounds • Holosystolic, crescendo-decrescendo or decrescendo,

Does sound matter?

  Most murmurs will worsen with smaller orifice size—so a very large VSD may have almost no pressure gradient across its mouth and thus little murmur but very large physiologic consequences.

Conversely, a small VSD may have a very turbulent jet with high velocity and a high pressure gradient across its mouth and be associated with a loud murmur, but have a much lower hemodynamic significance.

Grading the Sound

      I -faintest murmur that can be heard (with difficulty) II murmur is also a faint murmur but can be identified immediately III IV moderately loud loud with a palpable thrill V very loud, but still need stethoscope VI loudest and can be heard without stethoscope

S1 and S2

    Closing of the mitral (tricuspid, too) and aortic (pulmonic, too) valves Usually very crisp You should hear S1 loudest at mitral area You should hear S2 loudest at aortic area

Where do you hear murmurs?

• RUSB= (may radiate to neck ) • LUSB=Pulmonic (may radiate to back) • LLSB=Tricuspid (usually doesn’t radiate) • Apex=Mitral (may radiate to axilla)

Systolic murmurs

   • • • “swooshing” sounds Occur right after S1 (closing of mitral valve) and before S2 (closing aortic v) Causes: having trouble getting out of the ventricle through a tight door (aortic stenosis) You fall out through a door which should be closed tight but isn’t (mitral reg) A hole exists where it shouldn’t in the ventricular septum and blood crosses from high pressure side to low pressure side (VSD)

Mitral regurgitation

Mitral regurgitation

    Mitral valve is incompetent and does not close properly (door won’t close) Result: abnormal leaking of blood from the LV, through the mitral valve, and into the left atrium Causes: myxomatous degeneration, MI, dilated LV Sound: holosystolic (swoosh lasts throughout systole) radiates to axilla

Mitral and tricuspid valves – like a parachute

Systolic Murmurs

 Mitral Regurgitation (apex) • Systolic murmur • Radiates to axilla

S1 S2 S1

Mitral valve prolapse

   displacement of an abnormally thickened mitral valve leaflet that gets displaced into the atrium in systole Mid-systolic click with late systolic murmur You can get mitral regurg if severe

Aortic Stenosis

Aortic stenosis

     The aortic valve narrows Creates turbulent blood flow across the narrowed valve Result- the heart has to work hard by creating pressure to get blood across the stenotic valve Causes: congenitally bicuspid valve, wear and tear from age, Rheumatic fever Sound: crescendo-decrescendo murmur in systole, radiates to carotids

Physical Exam: Cardiac

 RUSB with diaphragm; radiates to carotids bilaterally

S1 S2 S1

VSD

VSD

     Congenital – hole in septum Left heart pressures>right heart So in systole, when heart contracts, the blood in the left goes across the “window” into the right side Holosystolic murmur, just like mitral regurgitation Only difference is that it is usually over the sternal border

  Systolic • Ventricular Septal Defect Continuous • Arteriovenous connections (PDA)

“Innocent murmur”

    AKA “physiologic murmur” Doesn’t radiate Occurs NOT from a structural problem in the heart but from something outside the heart Hyperthyroidism, anemia

Systolic Murmurs

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Innocent murmurs

• Usually ‘diamond shaped’, brief, little radiation • Common in children and young adults • ALWAYS: systolic, < III/VI intensity, other heart sounds and pulses are normal

S1 S2 S1

Diastolic murmurs= really bad

    Same “swoosh” but at a different time You hear it right after S2 and before S1 Blood is having trouble leaving the atrium to the ventricle b/c door is partly shut (mitral stenosis) Ventricular outflow tract can not stay shut (aortic regurg)

Aortic Regurgitation

Aortic regurg

    Aortic valve can not close fully Some blood that should go forward to the body now comes back into the heart Causes:congenitally bicuspid valve You hear the turbulence in diastole after aortic valve should have fully closed (after S2)

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Diastolic Murmurs

Aortic Regurgitation (Upper sternal) • radiates inferiorly • best heard with patient sitting up and leaning forward (in expiration)

S1 S2 S1

Mitral stenosis

Mitral stenosis

    Mitral valve is tight so blood can not get out of the atrium When the mitral valve area goes below 2 cm, the valve causes an impediment to the flow of blood into the left ventricle, creating a pressure gradient across the mitral valve. Pressure=turbulence=murmur Causes: Rheumatic heart dz, damage from endocarditis Sound: A mid-diastolic rumbling murmur will be heard after an opening snap. The murmur is best heard at the apical region and doesn’t radiate

Patent Ductus Arteriosis (PDA)

   In some babies the ductus arteriosus remains patent (connects pulm a and aorta) This opening allows oxygen-rich blood from the aorta to mix with oxygen-poor blood from the pulmonary artery. This can put strain on the heart and increase blood pressure in the lung arteries.

PDA

 Sounds like continuous machinery murmur throughout systole and diastole

  Systolic • Ventricular Septal Defect Continuous • Arteriovenous connections (PDA)

Split S2

  Physiologically split S2 • Natural delay in closure of pulmonic valve • Why? increase in pulmonary blood flow that occurs with inspiration when increased venous return to the right side of the heart delays the closure of the pulmonic valve Fixed Split S2= ASD • Increase pulmonary blood flow from increased preload from L->R shunt of blood across ASD delays closure of pulmonic valve • This split doesn’t change with respiration b/c ASD is more hemodynamically significant than the small increase in volume of blood that results from inspiration

Split S2

 Paradoxically Split S2 • You have split S2 in EXPIRATION • This can only happen when the aortic valve is delayed in closing.

• A LBBB will cause delayed depolarization of the left ventricle and a slightly delayed closing of the aortic valve!!

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S3

Only be heard with the bell, never with the diaphragm .This helps distinguish it clinically from a widely split S2. Is heard after S2 It can be normal in children and young people if no other abnormalities are reported on exam.

If other abnormalities are reported or the person is over 40, interpret this sound as caused by the blood entering a ventricle that is already volume and pressure overloaded (like CHF)

S4

    Caused by blood entering a thickened, stiffened ventricle.

Comes just before S1 in the cardiac cycle Can be left or right sided Can occasionally be heard in athletes but more commonly found in ventricular hypertrophy states or infiltrative cardiomyopathies (amyloid etc)

Rubs

   Pericardial rub= pericarditis This is a velcro sound that you can hear throughout the cardiac cycle Pericarditis • Recent upper resp tract infection • Chest pain that is better with leaning forward and worse with lying down