Fig. (10).

“Dual” cardiac memory induced by pacing from two different sites of the right ventricle in a 57 year old patient suffering from idiopathic dilated cardiomyopathy. A: During baseline atrial pacing (AP) at a cycle length (CL) of 700 ms, low voltage QRS complexes, incomplete right bundle branch block and negative T waves in leads II, III, aVF, and V4 to V6 were recorded. B: wide positive QRS complexes were induced in leads II, III, aVF and V4 to V6 by right ventricular outflow tract pacing (RVOTP) during a 15 min period. C: after cessation of RVOTP, T waves turned positive in inferior and left precordial leads. Please note that the T waves also became less positive in leads V2 and V3 and negative in leads V1 and aVL, in which the paced QRS complexes had been negative. D: once baseline conditions resumed, a 15-min period of right ventricular apical pacing was performed, after which the T waves turned negative (E) in all precordial leads (even more negative than at baseline in V4 to V6).