A QRS morphology shift following catheter ablation occurred in 4% of patients with idiopathic outflow tract ventricular arrhythmias, requiring detailed remapping to eliminate recurrent arrhythmias.
Observational (n=446)
What is the prevalence, mapping features, and ablation outcomes of QRS morphology shift following catheter ablation in patients with idiopathic outflow tract ventricular arrhythmias?
A QRS morphology shift occurs in 4% of patients undergoing catheter ablation for idiopathic OT-VAs, requiring detailed remapping as the successful ablation site often shifts to a different but adjacent anatomical structure.
INTRODUCTION: In patients with monomorphic idiopathic outflow tract ventricular arrhythmias (OT-VAs), catheter ablation (CA) at the earliest activation site can result in a shift in QRS morphology indicating a change in the activation patterns. This study aimed to investigate the prevalence, mapping features, and ablation outcomes of OT-VAs displaying a QRS morphology shift following CA. METHODS AND RESULTS: We retrospectively analyzed 446 patients with monomorphic OT-VAs. A QRS morphology shift following CA was observed in 17 (4%) patients. Initially, the earliest activation site was within the right ventricular outflow tract (RVOT) in one (6%) patient, the left ventricular outflow tract (LVOT) in 10 (59%) patients (left coronary cusp/right coronary cusp junction in seven patients and LVOT endocardium in three patients), and within the distal coronary venous system in six (35%) patients. The VA was suppressed in all 17 patients, but VA recurrence with a different QRS morphology was observed after a waiting period. The recurrent VA was remapped in all patients and was eliminated targeting the new earliest site in 15 (88%) cases. In 11 of 15 successful cases, the ablation site for the recurrent VA shifted to an anatomical structure distinct from but adjacent to the initial site. In the remaining four patients, the recurrent VA was eliminated within the same anatomical structure. CONCLUSIONS: In patients with idiopathic OT-VAs, a QRS morphology shift following CA can be observed in 4% of the cases. In these cases, detailed remapping is necessary since the successful ablation site for the VAs with altered QRS morphology shifts to different anatomical structures in most patients.
Shirai et al. (Mon,) conducted a observational in monomorphic idiopathic outflow tract ventricular arrhythmias (n=446). Catheter ablation was evaluated on QRS morphology shift following catheter ablation. A QRS morphology shift following catheter ablation occurred in 4% of patients with idiopathic outflow tract ventricular arrhythmias, requiring detailed remapping to eliminate recurrent arrhythmias.