ATRIAL SYSTOLE
From peak of QRS complex in ECG
Ventricular volume increase mildly
4th heart sound
Atrial pressure rises ‘a’ wave in JVP
curve
Atrial pressure exceeds ventricular
pressure
Ends by closure of mitral valves
ATRIAL DIASTOLE
Coincides with ventricular systole
Venous return, atrial volume, atrial
pressure increases
‘c’ wave due to bulging of tricuspid
valve to atrium
VENTRICULAR SYSTOLE
1)ISOVOLUMETRIC CONTRACTION