Fig. 5.

In vitro recordings from an excised Purkinje site of origin of focal VT labeled as Fig. 4, including calibrations. A: with Iso, pacing at 4 Hz produces two DADs, with one TA. Note the spontaneous action potential occurring ∼4 s after the last DAD, indicating slow Purkinje automaticity. B: addition of losartan to Iso allows three TA complexes at the same frequency of pacing. C: adding PD to Iso and losartan blocks TA, leaving a small DAD.