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: Cardiac sounds: Stethoscope 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’s number
= inertial force / viscous force
= (length X velocity X density) / (viscosity)
= length X velocity X constant
Reynold’s number > 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
MANEUVER
Supine
Standing
Valsalva
Deep Inspiration
Deep Expiration
AORTIC STENOSIS  
HOCM

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 Maneuvers:
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 intoduces regurgitant 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. Effect of Physiological Maneuvers on Murmur
LIVE Physical Examination: Maneuvers Differentiate aortic stenosis (AS) and hypertrophic cardiomyopathy (HOCM)
Effect of Physiological Maneuvers on Murmur
MANEUVER
Supine
Standing
Valsalva
Deep Inspiration
Deep Expiration
AORTIC STENOSIS  
HOCM

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
Alexander RW et al. The Heart. McGraw-Hill. New York, NY. 1998