Heart Sound S2:
From top to bottom :
1. Increased Component (intensity)
2. Decreased Component
3. A2 delayed , P2 early (narrow split)
4. A2 early , P2 delayed (Wide Split)
Wide and Fixed split -- ASD
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Physiological Split : During Inspiration
It induces an increase in venous blood return from the body into the right atrium.
Simultaneously, there is a reduction in blood volume returning from the lungs into the left ventricle
Since there is an increase in blood volume in the right ventricle during inspiration, the pulmonary valve (P2 component of S2) stays open longer during ventricular systole due to an increase in ventricular emptying time, whereas the aortic valve (A2 component of S2) closes slightly earlier due to a reduction in left ventricular volume and ventricular emptying time.
Thus the P2 component of S2 is delayed relative to that of the A2 component.
Marvellous ...
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