Cardiac Auscultation: An Art Based on Science

1
Cardiac Auscultation An Art Based on Science

• Samuel G. McDowell, M.D.
• Wake Forest University Baptist Medical Center
• Department of Internal Medicine

2
Cardiac Auscultation

• Current proficiency, attitudes, and teaching
  trends
• Twelve clinically important cardiac events that
  every internist should know
• Diagnostic accuracy of cardiac examination
• Conclusions

3
Teaching Trends

• Mangione et al. Ann Intern Med. 1993
• All 659 IM and cardiology program directors were
  surveyed (498 - 75.6 included)
• Structured teaching of cardiac auscultation
• Relative importance
• Clinical value of recognizing 11 events (S3, S4,
  ESCLK, MSCLK, OS, RUB, MR, AS, MS, AI, PDA)
• Proficiency test
• 187 IM residents, 16 cardiology fellows, 49 MS3
  tested using 12 events (as above with AS/AI)

4
Teaching Trends

• Teaching Trends
• Only 27.1 IM programs and 37.1 cardiology
  programs offered structured training
• Great clinical importance (5.3 IM, 5.46
  cardiology)
• All 11 cardiac events clinically relevant (4.5 -
  5.8)
• Proficiency Test
• Cardiology fellows (21.9 median) were
  statistically most accurate, but IM residents
  (19.3 median) were never statistically more
  accurate than MS3
• Less than 10 identified AS/AI, OS, MS, ESCLK,
  and MSCLK

5
Current Proficiency

• Mangione et al. JAMA. 1997
• Future primary care physician skills
• 453 residents (198 IM, 255 FP) from Mid-Atlantic
  programs as well as 88 medical students
• Tested on accuracy using 12 directly recorded
  cardiac events (MR, AS, AS/AI, AI, MS, PDA, RUB,
  S4, S3, OS, MSCLK, ESCLK)
• Attitudes of residents were surveyed
• Data analyzed by program, year of training, self
  motivated teaching

6
Current Proficiency

• Proficiency Test
• IM (1.2/12) more accurate than FP (0.9/12) with
  p0.02, but same as medical students (1.1/12)
• Adding in partially correct answers only led to
  20 accuracy rate for all events
• No overall improvement in accuracy from medical
  students to residents
• No overall improvement in accuracy with
  self-teaching

• Residents were incorrect 4 of 5 times,
  improved
• little with year of training, and were not
  more
• accurate than a group of medical students.

7
The Cardiac Cycle Events
Systole
Diastole
Early
Mid
Late
Early
Mid
Late
S1
S2

• Ejection Sound

• Opening Snap

• Mid Systolic Click

• S3

• S4

• Late Systolic Murmur (MVP)

• Pericardial Rub

8
Early Systolic Ejection Click

• High frequency sound 0.03-0.07 second after S1
• Genesis
• Sudden upward doming of abnormal semilunar valve
  in systole
• Sudden distention of a great artery
• Pulmonic ejection sounds often decrease in
  intensity with inspiration (LSB)
• With outflow obstruction the presence of a click
  implies mobility of valve cusps and identifies
  the level as valvular

9
Early Systolic Ejection Click
Systole
Diastole
Early
Mid
Late
Early
Mid
Late
S1
S2

• Ejection Click

• Bicuspid Aortic Stenosis (Ejection Click and
  Murmur)

10
Mid Systolic Click

• High frequency sound diagnostic of MVP
• Late systolic murmur at the apex
• Click produced by systolic prolapse of mitral
  valve leaflets into the left atrium with tensing
  of chordae tendinae
• Valsalva or standing - click towards S1 with
  lengthening of murmur (decreased LV volume)
• Hand grip or squatting - click towards S2 with
  shortening of murmur (increased LV volume)

11
Mid Systolic Click
Systole
Diastole
Early
Mid
Late
Early
Mid
Late
S1
S2

• Mid Systolic Click

• MVP (Click with Late Systolic Murmur)

12
Opening Snap

• High frequency sound associated with MS that
  occurs 0.04-0.12 second after S2
• Late peaking diastolic murmur
• Sound produced by rapid reversal of the superior
  bowing of the anterior mitral valve leaflet
  during diastole (high LA pressure)
• Generally the closer the OS to S2 (lt0.07 second)
  and the longer the murmur, the more severe the
  mitral stenosis

13
Opening Snap
Systole
Diastole
Early
Mid
Late
Early
Mid
Late
S1
S2

• Opening Snap

• Mitral Stenosis (OS and Late Diastolic Murmur)

14
S3

• Low frequency sound 0.14-0.22 second after S2
• Generated during rapid ventricular filling phase
  in diastole (prior to atrial contraction)
• Can be normal up to age 40
• LV S3 best heard at apex, whereas RV S3 best
  heard at LLSB or subxiphoid area (louder with
  inspiration)
• Augmented by passive leg raise

15
S3
Systole
Diastole
Early
Mid
Late
Early
Mid
Late
S1
S2

• S3

• S3 Gallop

16
S4

• Low frequency sound 0.08-0.20 second prior to S1
• Generated during presystolic ventricular filling
  due to atrial contraction
• Seen in diastolic dysfunction, significant AS,
  HTN
• LV S4 common during acute coronary syndromes
  (decreased wall contraction/motion)
• Standing moves S4 closer to S1 (or disappears)

17
S4
Systole
Diastole
Early
Mid
Late
Early
Mid
Late
S1
S2

• S4

• S3

• Opening Snap

18
Pericardial Rub

• Typically triple phased
• Scratchy/leathery sound produced by apposition of
  abnormal visceral and parietal pericardial
  surfaces
• Augmented with firm stethoscope pressure and held
  exhalation, leaning forward
• Can also be double or single phased (mid systolic
  component most persistent, followed by late
  diastolic, then mid diastolic)

19
Pericardial Rub
Systole
Diastole
Early
Mid
Late
Early
Mid
Late
S1
S2

• Triple Phased Pericardial Rub

• Double Phased Pericardial Rub

20
Aortic Stenosis

• Congenital, rheumatic, degenerative-calcific
• Heard best at right base and often radiates to
  the right carotid
• Crescendo-decrescendo, mid to late peaking
  systolic murmur (harsh)
• Intensity varies with cycle length (louder after
  a pause)
• Can have a more musical quality at the apex
  (Gallavardin effect)

21
Aortic Stenosis
Systole
Diastole
Early
Mid
Late
Early
Mid
Late
S1
S2

• Aortic Stenosis

• Aortic Stenosis with Ejection Click

22
Mitral Regurgitation

• Endocarditis, ischemic heart disease, MVP
• Typically a high frequency, holosystolic, plateau
  murmur heard best at the apex with radiation to
  the left axilla or back
• Does not change in intensity with cycle length
• Can be associated with a loud S3
• Can be more intense with isometric handgrip or
  stand to squat

23
Mitral Regurgitation
Systole
Diastole
Early
Mid
Late
Early
Mid
Late
S1
S2

• Mitral Regurgitation

24
Aortic Insufficiency

• Congenital (with AS), rheumatic, endocarditis,
  VSD, CVD
• High frequency (blowing), decrescendo, diastolic
  murmur heard best at 3rd-4th LIS (chronic)
• Can radiate to top of head
• Radiation to the right sternal border implies
  aortic root dilatation (Marfans)

25
Aortic Insufficiency
Systole
Diastole
Early
Mid
Late
Early
Mid
Late
S1
S2

• Aortic Insufficiency

• Aortic Stenosis with Aortic Insufficiency

26
Mitral Stenosis

• Rheumatic, congenital, endocarditis, amyloidosis
• Typically low frequency rumble or late peaking
  diastolic murmur heard best at apex beat
• Often associated with OS and loud S1
• Can be confused with Austin Flint murmur and be
  associated with Graham Steell murmur
• Mitral stenosis may be concealed under a quarter
  of a dollar.
• - Olser

27
Mitral Stenosis
Systole
Diastole
Early
Mid
Late
Early
Mid
Late
S1
S2

• Mitral Stenosis

28
Patent Ductus Arteriosus

• 15 of congenital heart disease (lt5 at age 50)
• Machinery/continuous murmur typically
  enveloping S2 and heard best at the left base
• If pulmonary HTN develops, the murmur may
  systematically disappear (with reversal of flow)
• Differential cyanosis (feetgthands)
• Mimicked by venous hum (more common)

29
Patent Ductus Arteriosus
Systole
Diastole
Early
Mid
Late
Early
Mid
Late
S1
S2

• Patent Ductus Arteriosus

30
Dynamic Auscultation

• Lembo et al. NEJM. 1988
• 50 outpatients with at least I/VI systolic
  murmurs, lesions confirmed by LHC or echo - PS,
  TR, AS, HOCM, MR, MVP, VSD
• Evaluated by 2 cardiologists (blinded) with an
  electronic stethoscope
• Assessed change in murmur with respiration,
  Müller, Valsalva, squat to stand, stand to squat,
  passive leg raise, isometric handgrip, transient
  arterial occlusion, amyl nitrite
• Observer vs expected response with given lesion

31
Dynamic Auscultation

• 87 agreement between cardiologists
• Right-sided murmurs (PS, TR) increased with
  inspiration (sensitivity 100, specificity 88)
• HOCM murmur decreased with stand to squat
  (sensitivity 95, specificity 85) - and vice
  versa
• MR/VSD increased with transient arterial
  occlusion (sensitivity 78, specificity 100) and
  isometric handgrip (sensitivity 68, specificity
  92)
• Accurate diagnosis is possible with systematic
  use of dynamic auscultation

32
Accuracy in Asymptomatic VHD

• Roldan et al. Am J Cardiol. 1996
• 143 patients (68 healthy and 75 with CVD but no
  cardiac symptoms) underwent TEE and complete
  cardiac examination by an experienced
  cardiologist (blinded)
• VHD included MR, MVP, bicuspid AV, PS, AI, TR, PI

• VHD detected in 33 patients (23) by TEE and 25
• patients (19) by exam

33
Accuracy in Asymptomatic VHD

• Exam had 70 sensitivity, 98 specificity, 92
  PPV, and 92 NPV
• Exam overcalled in 2 cases (AS and MS were not
  present - rather AV thickening/AI and AI alone)
• Only 2 of 10 patients with abnormal valves by TEE
  and not by exam had more than mild regurgitation
  or other clinically significant lesion
• Dynamic auscultation distinguished functional
  murmurs (31) from pathologic murmurs (13) with
  specificity 98 and PPV 92

34
Conclusions

• Cardiac auscultation is an accurate diagnostic
  tool
• Experience is important
• Structured/methodical use is key
• Current proficiency is lacking despite interest
• Teaching is limited
• Crucial to cost-effective screening of the
  population
• Particularly in a managed care setting
• It is the essence of medicine
• Fosters patient trust/confidence
• Can make the diagnosis with the senses