Click on image to view larger version.

Figure 2 Two examples of pause-dependent MVT. In both panels, the initiation of MVT (open arrows) is preceded by characteristic "short-long-short" sequences. The numbers above the horizontal arrows show duration of RR intervals in milliseconds. Asterisks in Panel A indicate electrograms with morphologies similar to those in baseline rhythm. Closed arrows in Panel B indicate pacing artifacts followed by the captured ventricular beats. Because only the first four beats of VT in Panel B display polymorphic morphology, the tachycardia was classified as monomorphic.