Lec 6 Auscultation and Heart Sounds

Question 1

What does the P wave signify?

Answer 1

atrial depolarization

Question 2

When does atrial contraction normally occur?

Answer 2

last third of diastole

Question 3

What does the QRS complex signify?

Answer 3

ventricular depolarization

Question 4

Which is relatively louder in males and females, S1 or S2?

Answer 4

in females: S1>S2

in males: S2>S1

Question 5

What is the significance of the length of PR interval?

Answer 5

determines softness of loudness:
long PR interval- soft sound
short PR interval- loud sound

Question 6

What does an abnormally loud S1 indicate?

Answer 6

early rheumatic mitral stenosis, hyperkinetic states

Question 7

What does an abnormally soft S1 indicate?

Answer 7

late mitral stenosis, contractile dysfunction, beta-adrenergic receptor blockade

Question 8

When does physiologic splitting occur?

Answer 8

during inspiration

Question 9

What are the possible causes of wide splitting between S1 and S2

Answer 9

right bundle branch block, severe pulmonary hypertension, pulmonic stenosis

Question 10

What are the possible causes of a delay in A2 (paradoxical splitting)

Answer 10

left bundle branch block, aortic stenosis, left ventricular dysfunction, left hypertrophic cardiomyopathy

Question 11

What heart condition causes a fixed/persistent splitting upon auscultation?

Answer 11

ASD

Question 12

What heart condition causes an ejection sound to be heard upon auscultation?

Answer 12

bicuspid semilunar valves, stenotic semilunar valve

Question 13

factors that decrease LV volume

Answer 13

standing, amyl nitrate

Question 14

factors that increase LV volume

Answer 14

squatting, phenylephrine

Question 15

What causes an opening snap to be heard?

Answer 15

stenosed AV valve (usually mitral)

Question 16

Where is an opening snap sound best heard?

Answer 16

slightly medial to cardiac apex

Question 17

How is the A2-OS interval related to the severity of stenosis?

Answer 17

A2-OS interval is inversely proportional to the severity of stenosis

Question 18

How can OS be differentiated from split S2?

Answer 18

1. OS does not vary with respiration

2. Split S2 is normally confined to 2nd ICS while OS radiates to a larger area over the left sternal border

Question 19

What is the significance of a pericardial knock?

Answer 19

abrupt cessation of ventricular expansion after tricuspid valve opening (corresponds to an exaggerated y descent in JVP)

Question 20

Which heart sounds are part of the so-called gallop rhythm?

Answer 20

S1, S2, and possibly S3 and/or S4

Question 21

What is the significance of a S3 sound?

Answer 21

abrupt cessation of ventricular distention; oscillation of blood between the ventricular walls

Question 22

What is the cut-off age for determining whether a S3 sound is physiologic or pathologic?

Answer 22

40

Question 23

What is the significance of a S4 sound?

Answer 23

turbulence in blood flow in the ventricle due to forceful atrial contraction (indicates a ventricular compliance problem)

Question 24

In what position is the S4 sound best heard?

Answer 24

cardiac apex on left lateral decubitus position