O Positive deflections
S a = right atrial contraction. It is absent in atrial fibrillation and increased by a conditions impeding right atrial emptying, such as tricuspid or pulmonary r y stenosis.
m c = right ventricular contraction, with bulging of the tricuspid valve into the right atrium during the initial isovolumic ventricular contraction. v = filling of right atrium against a closed tricuspid valve in late ventricular systole causing a rise in atrial pressure. This occurs prior to the opening of the tricuspid valve in ventricular diastole. It is prominent in tricuspid regurgitation.
Negative deflections x = atrial relaxation and downward movement of the leaflets of the tricuspid valve with ventricular contraction during the ejection phase. x' = atrial relaxation, with return of tricuspid valve into position. y = right atrial emptying through an open tricuspid valve.
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