Figure 1

Optimization of AV delay after CRT by pulsed Doppler mitral inflow pattern. At programmed AV delay of 180 ms (upper panel) the closure of mitral valve occurs before the onset of ECG QRS. Optimizing AV delay at 120 ms (lower panel), the diastolic filling time is much longer and the duration of atrial filling is preserved. (Modified from Agler DA, J Am Soc Echocardiogr 2007;20:76–90).