CLINICAL CARDIOLOGY LECTURE

The lecture at the lunchon conference, the University of Arizona, College of Medicine, on March 10, 2000.

Heart Sounds and Murmurs

T.Takashina,M.D.,Ph.D.,FAHA,FACC

Chairman,
Japanese Educational Clinical Cardiology Society (JECCS)
Asian Heart House

Foreword:
The first step in physical examination is to obtain a good history with precise bedside physical findings. This is true throughout the world.The advances in diagnostic instruments with the use of high technology in the last few decades are remarkable. However, there is a tendency for many clinicians to become too dependent on these highly sophisticated instruments and forget the importance of bedside clinical skills.
Now,I would like to talk about one of the bedside skills, focused on the cardiac auscultation by using, my son, SIMULATOR "K" today.

(A) To Perform the Auscultation:

1. Select a good stethoscocpe (some stethoscopes, the bell and diagphragm chest pieces equipped). Try several stethoscopes before you decide to purchase.
2. Select a good ear piece and tubing no greater than 12 inches.
3. A quiet room without extraneous noises is best. And also, don't talk with the patient while you listen heart sounds and murmurs. Please remember habitual users of "Walkman" never be the cardiologists!.
4. Change position of the patient (supine, left lateral or semilateral, upright, forward leaning, horizontal ( on his or her knees and elbows), standing and squatting).
5. All clothing should be removed from the chest. A towel is adequate to drape the female breasts.
6. Adapt a systematic way of listening:
   a. Start from the apex and then move to left sternal border, concentrate to listen one sound at a time, and to listen at the point of max. intensity.
   b. Ascend gradually along the LSB to the base.( called "inching"). Some cardiologists prefer to start from the base to apex.
   c. Listen and compare the intensity of the sounds at the aortic and pulmonic areas( particularly, pay your attention to the splitting of S2).
   d. Diagramming of heart sounds or murmurs at each auscultatory sites is recommended for the beginners.
   e. Stop breathing of the patient, as well as the examiner, while you listen the heart sounds or murmurs at each auscultatory site.
   f. Watch the jugular venous pulse, palpate the cartotid artery, while you listen the heart sounds (S1 and S2).
   g. Remember S1 is heard just right after the "a" wave of jugular venous pulse.

(B) Heart Sounds:

1. The important auscultatory sites are aortic area, pulmonic area, tricuspid area and mitral areas.
   
2. First sound (S1) is mainly caused by the mitral and tricuspid valve closure, with a rapid tension of chorda tendinea.
   
3. Second sound (S2) is mainly caused by the aortic and pulmonic valve closure.
   
4. Relation between S1 and S2 at apex in normal individua, S1 is louder than S2 ( if S2 is louder than S1, you should suspect the diastolic hypertension).
   
5. S1 intensity is reflected by the mitral rather than tricuspid closure ( in normal individual, somstimes.you can hear a splitting of S1 at the tricuspid area, by these valve closure.
   
6. In normal individual, S2 is louder than S1 at the aortic and pulmonic area.
   
7. The systolic ejection sounds(clicks) occurs in early systole approximately 40-60 msec.
   
8. The clicks are attributed to vibrations of the outflow tract of LV, the aortic wall and the blood in these chambers.
   
9. The pulmonary ejection sound (click) can occur in idiopathic dilatation of the pulmonary artery.
   
10. Mid-late nonejection systolic clicks commonly caused by MVP (mitral valve prolapse).
    
11. Valsalva maneuver, decreases LV volume, associated with MVP earlier in the cardiac cycle.
    
12. Other causes of nonejection clicks include: ventricular and atrial septal aneurysms, ventricular free wall aneurysm, ventricular and atrial tumors.
    
13. In healthy young adults, the physiological (respiratory) splitting of S2 is heard at the pulmonic area in 40-60%.
    
14. Occasionally, normal subjects appear to have fixed splitting of S2 in the supine position that becomes single in the upright position.
    
15. A fixed splitting ( no respiratory effect ) in ASD occurs in 60-70%.
    
16. A wide splitting is commonly heard in patients with CRBBB (complete right bundle branch block).
    
17. In normal individuals, only the aortic componenet(A2) of S2 is transmitted to the apex.
    
18. When both components of S2 (A2P2) are heard at the apex in adults, implying an increased of S2, suspect ASD, pulmonary hypertension.
    
19. Paradoxical splitting of S2 is commonly caused by a complete left bundle branch block.
    
20. Paradoxical splitting of S2 in HCM implies significant resting LV outflow tract gradient.
    
21. Transient paradoxical splitting of S2 can occur with myocardial ischemia.
    
22. The important points of auscultation in the pulmonic area are to check a loudness of S1 and S2, presence or absense of S2 splitting, presence or absence of continuous murmur, presence or absence of systolic and diastolic murmur.
    
23. Third sound (S3=physiological gallop) is heard in healthy young adults in 30 ~50%.
    
24. S3 (venirucular gallop) heard in older patients implies ventricular systolic failure usually with an increase in filling pressurer within the affected ventricle.
    
25. S3 in the patient with mitral valve regurgitation implies severe degree and failing heart.
    
26. The presence of an opening snap (OS), often accompanied by a loud S1 implies a pliable mitral valve (that not heavily calcified).
    
27. S4 (atrial gallop) may be heard as an early sign of diastolic dysfunction (in the absence of systolic dysfunction) and is easily differentiate from other heart sounds, and may also be abolished by pressing the chest piece of stethoscope hard at the apex.
    
28. S4 is present in most patients with a complete AV block, HCM, AMI, systemic hypertension and chronic ischemic heart disease.
    
29. A presence of the ventricular (S3) and atrial(S4) gallop sounds are called "quadruple rhythm". This is present in most patients of DCM and ventricular aneurysm.
    
30. When the heart rate is more rapid, the S3 and S4 are fused at mid-diastole and produce the so-called "summation gallop".
    

(C) Heart Murmurs:
A murmur is a relatively prolonged series of auditory vibrations, which may vary in loudness(faint, loud and very loud), pitch( low and high), quality(fine and coarse), timing, radiation and duration( short and prolonged).
By the timing, murmurs are classified: (a) systolic murmur ,(b) diastolic murmur and (c) continuous murmur.

(a) The systolic murmur begins with or after S1 and ends at or before S2.
(b) The diastolic murmur begins with or after S2 and ends at or before S1.
(c) The continuous murmur begins in systole and continues without inter- ruption through the time of the S2 into all or part of diastole.

Configuration of Murmurs is classified (a) crescendo, (b) decrescendo, (c) diamond-shaped(ejection) and(d) plateau or sustained(regurgitant).

Intensity (loudness) of murmurs is classified into 6 grades (Levine):

(1) A grade I murmur is so faint that it can be heard only with special effort ( common in normal people).
(2) A grade II murmur is faint but can be recognized readily( innocent in origin and can be heard 90% among healthy young children).
(3) A garde III murmur is moderately loud( usually hemodynamically significant, both ejection or regurgitant in origin).
(4) A grade IV murmur is very loud and usually associated with a palpable thrill on the chest wall ( VSD, severe MR, severe AR and PDA).
(5) A grade V murmur is extremely loud ( PDA, arterio-venous fistula and acute MR).
(6) A garde VI murmur is extraordinary loud and is heard with the stetho- scope just removed from contact with the chest wall (rupture of chorda tendinea, PDA and perforation of sinus Valsalva)

1. The systolic ejection murmur is heard in the following cases are: such as AS, PS, innocent murmur, ASD and HCM.
   
2. The innocent (functional) murmur can be heard in early systole, with short and soft (3S) in quality at pulmonic area.
   
3. Inspiration may accentuate the murmur of tricuspid regurgitation.
   
4. A severe TR are often associated bedside findings an elevated JVP with prominent, V waves, parasternal lift and pulsatile liver.
   
5. In MS, the mid-diastolic rumbling murmur at the apex begins with OS and lasts to S1.
   
6. In AR and MS, the duration of the diastolic murmurs is related to severity of the valve, significant pressure gradient across the valve, loudness of the murmur.
   
7. The early systolic ejection murmur in the ASD is caused by flow murmur across the foramen of ASD, flow murmur at the pulmonary valve.
   
8. Pansystolic murmur of VSD should be differentiated from TR and MR.
   
9. Venous hums, female breasts in postpartum period and hyperyhyroidism should be differentiated from AR ( to and fro murmur) are continuous murmurs.
   
10. The PDA produces a continuous murmur most commonly, however, when a murmur is loudest in the posterior thorax, consider the following: coactation of the aorta, pulmonary arterio-venous fistula, peripheral pulmonary stenosis.
    
11. Bedside physiological maneuvers to differentiate various heart murmurs are changing body position, inspiration and exhalation, hand grip test, Valsalva maneuver, amyl nitrate in all stenotic murmur; such as HCM, transient arterial occlusion, using blood pressure cuffs is accurate in assessing left sided regurgitant murmurs.

Without Auscultation,
No One Can Master the Cardiology.

T.Takashina, M.D.Ph.D.,F.A.C.C.
At the University of Arizona, College of Medicine
March 10, 2000

The lecture was very well received by medical students, residents and fellows.