Figure 8

Pulsed wave mitral inflow Doppler tracings obtained at AVD of 50 (A), 110 (B), 150(C), 170(D) 190(E), 270(F), 290(G), 310(H), and 330ms (I). Note absent mitral inflow A waves (white arrows) in panels A through D until an AV delay of 190 ms (E) is reached. Significant increase in atrial velocity and duration is seen at an AVD of 290 ms (Panel G). Further increase in AVD caused E and A approximation (H and I). White arrow heads next to EKG signals in each panel point at the p waves on electrocardiogram displayed on ultrasound system during progressively increasing AVD.