Cardio sounds Flashcards Preview

Cardio > Cardio sounds > Flashcards

Flashcards in Cardio sounds Deck (14):
1


S1

closure of the mitral&tricuspid valves at onset of ventricular systole □best heard at the apex

2


S2

and physiological splitting

closure of the pulmonary and aortic valves at the end of ventricular systole □best heard at the left sternal edge □louder and higher-pitched than S1, the aortic component is normally louder than the pulmonary one.

 

□Physiological splitting of S2 occurs because LV contraction slightly precedes that of RV so that the aortic valve closes before the pulmonary valve. □splitting ↑ at end-inspiration ← ↑ venous filling of the RV further delays pulmonary valve closure. □separation disappears on expiration □Splitting of S2 is best heard at the left sternal edge. On auscultation, you hear 'lub d/dub' (inspiration) 'lub-dub' (expiration).

3


S3

low-pitched □early diastolic

□best heard with the bell at the apex.

□coincides with rapid ventricular filling immediately after opening of the AV valvesheard after S2 as 'lub-dub-dum'.

□normal in children, young adults & during pregnancy.

4


Pathological S3

A S3 is usually pathological after the age of 40 years □commonly due to LV failure (early sign) & mitral regurgitation. ◊In heart failure S3 occurs with a tachycardia and S1 and S2 are quiet (lub-da-dub).

5


S4

□S4 is less common

soft and low-pitched

□best heard with the bell at the apex

□occurs just before S1 (da-lub-dub)

always pathological 

□caused by forceful atrial contraction against a non-compliant/ stiff ventricle

□often heard with LV hypertrophy (due to hypertension, aortic stenosis or hypertrophic obstructive cardiomyopathy) □cannot occur when there is AFib.

6

↑intensity of S1

due to and significance

abnormal

in mitral stenosis

due to increased Pressure in LA

7


Wide splitting of S2, but with normal respiratory variation

causes and significance

is in delayed RV emptying ←right bundle branch block

8


Fixed splitting of S2

significance and causes

i.e. no variation with respiration, → atrial septal defect (RV stroke volume is larger than the left; the splitting is fixed because the defect equalizes the pressure between the two atria throughout the respiratory cycle)

9


Abnormalities of intensity of S1

quiet?

loud?

variable?

Quiet:  1.↓ cardiac output  2. Poor LV function   3.Long P-R interval (1˚ heart block)  4.Rheumatic mitral regurgitation

Loud:  1.↑ cardiac output   2. ↑ stroke volume   3.Mitral stenosis  4. Short P-R interval   5.Atrial myxoma (rare)

Variable :   1.Atrial fibrillation   2. Extrasystoles   3. Complete heart block

 

10

Abnormalities in S2

Quiet:  1. ↓ cardiac output  2. Calcific aortic stenosis   3. Aortic regurgitation
Loud:  1.Systemic hypertension (aortic component)   2.Pulmonary hypertension (pulmonary component)

Split :
Widens in inspiration (↑physiological splitting):
1. Right bundle branch block   2. Pulmonary stenosis   3.Pulmonary hypertension   4. Ventricular septal defect


Fixed splitting (unaffected by respiration):  Atrial septal defect


Widens in expiration (reversed splitting):   1. Aortic stenosis   2.Hypertrophic cardiomyopathy  3.Left bundle branch block  4.Ventricular pacing

11

causes of a 3rd heart sound

Physiological : 1.Healthy young adults  2. Athletes  3.Pregnancy  4.Fever
Pathological :   1. Large, poorly contracting LV  2.Mitral regurgitation

12


Opening snap

□mitral (rarely tricuspid) stenosis → sudden opening of a stenosed valve

□early in diastole, just after S2

□best heard at the apex

13


ejection click


□early in systole just after S1

□congenital pulmonary or aortic stenosis

□do not occur in calcific aortic stenosis because the cusps are rigid

14

midsystolic clicks

□mitral valve prolapse □associated with a late systolic murmur □high-pitched and best heard at the apex
○Mechanical heart valves make a sound when they close and open. The closure sound is normally louder, especially with modern valves. The sounds are high-pitched, 'metallic' and often palpable, and may be heard without a stethoscope. A mechanical mitral valve replacement makes a metallic first heart sound and a sound like a loud opening snap. Mechanical aortic valves have loud, metallic second heart sounds and an opening sound like an ejection click. They usually also cause a flow murmur.