Deciphering Murmurs and Heart Sounds: A Comprehensive Guide

1. Murmurs and Myocardial Sounds…Making Sense of the Madness Sara G. Tariq, M.D. August, 2012

2. Goals • Know how we classify murmurs • Systolic • Crescendo-decrescendo • Aortic stenosis, pulmonicstenosis, 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 DuctusArteriosus

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

4. 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,

5. 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.

6. 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- moderately loud IV- loud with a palpable thrill V- very loud, but still need stethoscope VI- loudest and can be heard without stethoscope

8. 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

9. 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)

10. 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)

11. Mitral regurgitation

12. 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

13. Mitral and tricuspid valves – like a parachute

14. Systolic Murmurs • Mitral Regurgitation (apex) • Systolic murmur • Radiates to axilla S1 S2 S1

15. 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 Mitral valve prolapse

16. Aortic Stenosis

17. 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

18. Physical Exam: Cardiac • RUSB with diaphragm; radiates to carotids bilaterally S2 S1 S1

19. VSD

20. 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

21. Systolic • Ventricular Septal Defect • Continuous • Arteriovenous connections (PDA)

22. “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

23. Systolic Murmurs • 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 S2 S1 S1

24. 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)

25. Aortic Regurgitation

26. 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)

28. Diastolic Murmurs • Aortic Regurgitation (Upper Sternal) • radiates inferiorly • best heard with patient sitting up and leaning forward (in expiration) S1 S2 S1

29. Mitral stenosis

30. 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

31. 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.

32. PDA • Sounds like continuous machinery murmur throughout systole and diastole

33. Systolic • Ventricular Septal Defect • Continuous • Arteriovenous connections (PDA)

34. 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

35. 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!!

36. 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)

37. 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)

38. 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