Change in QRS morphology as a marker of spontaneous elimination in verapamil‐sensitive idiopathic left ventricular tachycardia

Change in QRS morphology as a marker of spontaneous elimination in verapamil‐sensitive... 1INTRODUCTIONVerapamil‐sensitive idiopathic left ventricular tachycardia (ILVT) occurs predominantly in young patients without structural heart disease. The majority of verapamil‐sensitive ILVT with a right bundle branch block (RBBB) configuration and left‐axis deviation (LAD) has been suggested to originate from the Purkinje network of the left ventricular posterior fascicle. Several previous studies have described radiofrequency catheter ablation (RFCA) of ILVT using multiple approaches, and the clinical usefulness of RFCA for ILVT has been well‐established. The long‐term prognosis of patients with ILVT is considered to be benign; thus, not all patients hope to undergo RFCA for ILVT because someone declines invasive treatment and/or ILVT cannot be induced at the time of electrophysiological studies (EPS). On the other hand, long‐term changes in 12‐lead electrocardiogram (ECG) measurements are still unclear.We hypothesized that further conduction delay in the LV fascicles might fail to maintain the reentry of verapamil‐sensitive ILVT. Thus, in this study we analyzed changes of 12‐lead ECG during long‐term follow‐up and investigated their relationship with VT recurrence.2METHODS2.1Study populationOne hundred seven consecutive patients referred to our hospital between January 1981 and August 2011 due to symptoms of ILVT and ECG‐documented ILVT were enrolled. All VT episodes were confirmed to be terminated by the intravenous Journal of Cardiovascular Electrophysiology Wiley