Approach to Cardiac Auscultation

1. Approach to Cardiac Auscultation Mehul Bhatt, MD Interventional Cardiology/Vascular Medicine Heart and Vascular Care 3rd Cherokee Cardiovascular Summit October 4, 2014

2. Approach to Cardiac Auscultation • Physiology • Sounds • Maneuvers • Pathology • Valvular Disease • Differentiating disease • Live Auscultation Cases • Aortic stenosis versus Hypertrophic cardiomyopathy

3. Physiology • Human ear: • 20 - 20,000 Hz • Best 1,000 – 5,000 Hz • Cardiac sounds: • 30 – 1,000 Hz • Stethoscope • Bell – low frequency sounds • Diaphragm – high frequency sounds Bell Diaphragm

4. Physiology: Sounds • S1: • S1 = M1T1: comprised of mitral valve closure (M1) then tricuspid valve closure (T1) • Hear high-frequency vibrations from deceleration of blood after valve closure (not clapping of valve leaflets together) • Usually heard as one sound

5. Physiology: Sounds • S2: • S2 = A2P2: comprised of aortic closure (A2) then pulmonary closure (P2) • Hear high-frequency vibrations from deceleration of blood after valve closure (not clapping of valve leaflets together) • Often heard as split sound • Normal split: increases with inspiration as P2 delayed with increased RV volume and pulmonary vascular capacitance; typically hear single S2 with expiration

6. Physiology: Sounds • Murmurs: • Cause: Turbulence / Non-laminar flow • Reynold’snumber = inertial force / viscous force = (length X velocity X density) / (viscosity) = length X velocity X constant • Reynold’snumber > 30: turbulent or non-laminar flow • When: • High flow rate through normal or abnormal orifice • Flow through constricted or irregular orifice into dilated area • Backwards or regurgitant flow

7. Physiology: Maneuvers • Position • Supine: • Increase preload: increased blood volume in heart • Rapid standing: • Decrease preload: decreased blood volume in heart • Valsalva (bear down) • Decrease venous return (preload) • Breathing • Deep breath in: Increased preload • Deep breath out: Decrease preload

8. Pathology: Aortic Valve Stenosis • Bicuspid AV stenosis: • Occurs in ages 40s-50s • Senile AV stenosis: • Occurs in aged 70s-80s • Progressive obstruction • Severity determined by exam, echo, and cardiac cath Normal AV Stenotic AV

9. Pathology: Aortic Valve Regurgitation • Incompetent aortic valve • Maybe in conjunction with aortic stenosis • Maybe associated with dilated aorta root

10. Pathology: Aortic Valve Stenosis • Aortic stenosis • Mid-systolic high-frequency cresendo-descrendo • May have ejection sound and soft S2 based on calcification (valve motion)

11. Pathology: Aortic Valve • Manuevers: • Decrease afterload or increase preload: Lying down, Deep breath in accentuate murmur; • Increase afterload or decrease preload: Standing, Deep breath out attenuate murmur

12. Pathology: Aortic Valve • Aortic Regurgitation • Early diastolic descrendo high-frequency murmur • Maneuvers: • Increase afterload: squatting, isometric exercise (sustained handgrip) accentuate murmur

13. Pathology: HOCM • Hypertrophic cardiomyopathy: • Dynamic restriction of LVOT due to thickening of ventricular septal muscle • Genetic and environmental components • Cause of sudden cardiac death • Often in young athletes

14. Pathology: HOCM • Hypertrophic cardiomyopathy • Harsh systolic murmur with varying frequencies • Murmur combination of mid-systolic ejection from obstruction and holosystolic from MR and TR • S2 is intact as aortic valve in normal • Suspect when heart harsh systolic murmur in young person (although maybe bicuspid aortic valve) • Murmur more dyanamic with maneuvers than aortic stenosis murmur

15. Pathology: HOCM • Hypertrophic cardiomyopathy • Maneuvers: • Decrease gradient: Increase preload or Increase afterload will decrease murmur: • Standing to Supine (increase preload), squatting (increase preload + afterload), inspiration (increase preload)

16. Pathology: HOCM • Hypertrophic cardiomyopathy: • Manuevers: • Increase gradient: Decrease preload or Decrease afterload will increase murmur: • Supine to standing, Valsalva (decrease preload)

17. Pathololgy: Aortic stenosis versus Hypertrophic cardiomyopathy

18. Pathology: Mitral • Mitral stenosis • Mid-diastolic and pre-systolic low frequency“rumble” • Murmur after mitral opening snap • Opening snap: depend on calcification α 1/valve mobility • Often difficult to hear as soft and low frequency • Aerobic exercise and left lateral decubitus position accentuate

19. Pathology: Mitral • Mitral regurgitation • Holosystolic constant high-frequency • Maneuvers: • Typical MR and Rheumatic MR: • Increase with increase afterload • Not effected much by respiration • Mitral valve prolapse: • Significant changes with respiration

20. Pathology: Mitral Valve Prolapse • Mitral valve prolapse “floppy valve syndrome” • Incompetent mitral valve that allows blood to leak back into left atrium during left ventricular systole • Can be seen in Marfan’s syndrome, Ehlers-Danlos syndrome • Murmurs very sensitive to breathing manuevers

21. Pathology: Mitral • Mitral valve prolapse • Redundant mitral valve tissue • “Too much tissue for size ventricle” • Mid- to late-systolic click intoducesregurgitant murmur • Maneuvers: • Increase size of ventricle: delay click and murmur; murmur softer • Deep inspiration, supine • Decrease size of ventricle: earlier click and murmur; murmur louder • Valsalva, standing

22. LIVE Physical Examination:Maneuvers Differentiate aortic stenosis (AS) and hypertrophic cardiomyopathy (HOCM) Effect of Physiological Maneuvers on Murmur

23. Approach to Cardiac Auscultation: References • Dr. Joseph Esterson, MD Director, Cardiology Training Center for Research and Medical Education University of Miami School of Medicine • Braunwald E et al. Heart Disease. W.B. Saunders Co. Philidelphia, PA. 2001. • Alexander RW et al. The Heart. McGraw-Hill. New York, NY. 1998 • http://depts.washington.edu/~physdx/heart/demo.html • http://egeneralmedical.com/egeneralmedical/listohearmur.html • http://home.cwru.edu/~dck3/heart/listen.html • http://www.auscultation.com/