Heart Sounds

• Overview of Heart Sounds

1. lub-dub,
2. lub - closure of AV valves, onset of ventricular systole
3. dub - closure of semilunar valves, onset of diastole
4. Pause - quiescent period of cardiac cycle
5. Tricuspid valve (lub) - RT 5th intercostal, medial
6. Mitral valve (lub) - LT 5th intercostal, lateral
7. Aortic semilunar valve (dub) - RT 2nd intercostal
8. Pulmonary semilunar valve (dub) - LT 2nd intercostal

• Heart Murmurs

1. Murmur - sounds other than the typical "lub-dub"; typically caused by disruptions in flow
2. Incompetent valve - swishing sound just AFTER the normal "lub" or "dub"; valve does not completely close, some regurgitation of blood
3. Stenotic valve - high pitched swishing sound when blood should be flowing through valve; narrowing of outlet in the open state

Category: Physiology Notes