An intramural focus in the interventricular septum was identified in 8% (7 of 93) of patients with idiopathic ventricular arrhythmias, requiring specific mapping and ablation strategies.
Observational (n=93)
Idiopathic septal ventricular arrhythmias can originate from intramural foci, which may require ablation from within the septum or both sides for effective elimination.
BACKGROUND: Intramural septal idiopathic ventricular arrhythmias have not been described systematically. METHODS AND RESULTS: In a consecutive group of 93 patients with idiopathic ventricular arrhythmias referred for ablation, the site of origin of ventricular arrhythmias was assessed by activation mapping and pace-mapping. In 7 of 93 patients (8%), an intramural focus in the interventricular septum was identified. All ventricular arrhythmias arising intramurally had a left bundle-branch block morphology with inferior axis. The intramural focus was effectively ablated from both sides of the septum in 4 patients and from within the septum in 1 patient. The ablation procedure of an intramural focus near the His bundle failed in 2 of 7 patients. ECG and mapping characteristics of the patients with intramural septal ventricular arrhythmias differentiated intramural arrhythmias from other sites of origin. CONCLUSIONS: Idiopathic septal ventricular arrhythmias can originate from intramural foci. Activation mapping from within a perforator branch within the interventricular septum is helpful in identifying the site of origin of intramural septal arrhythmias. Ablation within the septum or from both sites of the septum may be required to eliminate the targeted arrhythmia.
Yokokawa et al. (Sat,) conducted a observational in Idiopathic ventricular arrhythmias (n=93). Activation mapping, pace-mapping, and ablation was evaluated on Identification of an intramural focus in the interventricular septum. An intramural focus in the interventricular septum was identified in 8% (7 of 93) of patients with idiopathic ventricular arrhythmias, requiring specific mapping and ablation strategies.