Modulation of the expression of long-term cardiac memory by short-term cardiac memory in patients with Wolff-Parkinson-White syndrome after catheter ablation.

BACKGROUND: The interaction between long-and short-term cardiac memory (CM) is unknown. METHODS AND RESULTS: The T-wave areas and QTc intervals in each ECG lead were analyzed in 11 patients with manifest Wolff-Parkinson-White syndrome with posterior or septal accessory pathway (4 females; mean age: 47+/-12 years) in the following ECGs: (1) immediately after catheter ablation (post-ablation ECG); (2) immediately after 20 min of right ventricular outlet pacing (post-pacing ECG); and (3) 1 week after ablation (recovery ECG). Compared with the post-ablation ECGs, the T-wave areas of the recovery ECGs in leads II and aV(F) changed dramatically from negative to positive while that in lead III became less negative (p<0.01), and those in leads I, aV(L), and V(2-4) became less positive (p<0.05). Compared with the post-ablation ECGs, the T-wave areas of the post-pacing ECGs in leads III and aV(F) became less negative (p<0.01), and those in leads I, aV(L), and V(2-4) became less positive (p<0.05). The QTc interval in the post-ablation ECG was significantly longer than in either the post-pacing or recovery ECGs (p<0.05). CONCLUSIONS: Mechanisms involved in the expression of long-term CM could be affected by short-term CM.