Figure 2

Calculation of interventricular mechanical delay by standard Doppler method. The time from ECG Q wave to onset of left ventricular outflow tract (= 211 ms) (left panel) is longer than the time occurring from Q to onset of right ventricular outflow tract (= 122 ms). The resulting inter-ventricular mechanical delay (IVMD) is of 89 ms, thus indicating a significant interventricular dyssynchrony.