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Figure 4 Surface ECGs and intracardiac electrogram (RV, right ventricular outflow tract) recorded at induction of monomorphic VT (CL, 225 ms) during baseline EPS in a patient with unexplained syncope (A). Stored ICD intracardiac electrogram recorded between proximal and distal shocking electrodes (B) in the same patient two and a half months later. This spontaneous tachycardia (rate 265 beats/min, CL 226 ms) resulted in syncope and was terminated by a 34-J shock.