Ultrasound

Doppler Image

Diastolic filling is influenced by the compliance of the ventricular wall. In adults and older children trans-mitral flow occurs in two phases; an early phase of passive flow during which the majority of the filling occurs and a late atrial contraction phase during which the remaining third of the venous return to the ventricle is delivered. In patients with diastolic dysfunction, the majority of filling occurs during the atrial phase as the stiff ventricular wall prevents passive early flow across the mitral valve. The immature fetal and preterm myocardium is characterized by impaired diastolic function. Pulsed wave Doppler can be used to examine this biphasic pattern of the RV and LV inflows. First phase is the early wave (E wave) and is a result of passive blood flow across the atria-ventricular valves in early diastole. The second phase is the atrial contraction wave (A wave) and is a result of atrial contraction at the end of diastole.