THE RATIONAL PHYSICAL EXAM

Implications of the 3rd Heart Sound and the Diastolic Noises

I. The Exam:

Listening for triplets - a couplet (either S4 + S1 or S2 + S3) followed by a single sound. Must identify the S1 and S2 clearly. At the base, the louder sound will be the S2, at the apex the louder sound is the S1.

II. The S3: Ken - Tuck - y = S1...S2...S3

Best heard at apex, left lateral decubitus with the bell of the stethoscope in a quiet room with NR < 90 b/min. The noise is heard when the LV free wall and septum reach the limit of diastolic excursion.

III. Clinical Occurrence:

Normal in kids, young adults. Not so serious if occurs in diastolic overload from anemia, thyrotoxicosis AV shunt. More serious indicator of myocardial dystxn and increased LV filling pressures and increased PAP, L atrial pressures in older persons.

In a recent study, the S3 was studied in 1,281 patients with 6 types of valvular heart diseases
(Folland, et al, NEJM 1992;327:458-62). The following data were derived from this study:

Type of Valve

Dz

% with S3

LVEF (+S3)

LVEF (-S3)

PcwP (+S3)

PcwP (-S3

AS

11

38 ± 15 *

56 ± 14 *

18 ± 10 *

12 ± 7 *

AS + AR

14

40 ± 15 *

55 ± 12 *

24 ± 10 *

14 ± 7 *

AR

28

48 ± 12

51 ± 12

16 ± 9

13 ± 6

MS

8

53 ± 16

47 ± 14

22 ± 10

22 ± 8

MS + MR

26

47 ± 15

50 ± 13

26 ± 6 *

19 ± 7 *

MR

46

51 ± 14

57 ± 14

19 ± 7

17 ± 9

* for this, just choose an asterisk symbol and insert in all places p < 0.01

Conclusions: In patients with mitral regurgitation, third heart sounds are common but do not necessarily reflect left ventricular systolic dysfunction or increased filling pressure. In patients with aortic stenosis, third heart sounds are uncommon but usually indicate the presence of systolic dysfunction and elevated filling pressure. (N Engl J Med 1992;327:458-62).

IV. Other Abnormal Diastolic Sounds:

Basal: Aortic Regurgitation

Pulmonary Regurgitation

Mid Precordial: Coronary Artery Stenosis

Tricuspid Stenosis

Apical: Mitral Stenosis

Secondary Mitral Stenosis

Pericardial Knock: earlier than an S3 in diastole

The S4 Gallop: Tenn - U - See = S4.S1...S2

Audible just before the S1. Common to hear this sound especially in hypertensive pts. often transient. Heard in normals, too.

Other: A5, NOCM, A5CVD, anemia, hyperthyroidism, AVF

Summation Gallop: sounds of S3 and S4 are so close together that it gives the impression

of a rumbling murmur. Vagal stimulation may help distinguish 4 separate sounds

(S1-S4).

 

References:

NEJM, 1992;327:458-62

DeGowin and DeGowin. Bedside Diagnostic Examination