Left-Sided Ablation of Ventricular Tachycardia in Adults With Repaired Tetralogy of Fallot

Abstract

Background-Radiofrequency catheter ablation (RFCA) of ventricular tachycardia (VT) in repaired Tetralogy of Fallot focuses on isthmuses in the right ventricle but may be hampered by hypertrophied myocardium or prosthetic material. These patients may benefit from ablation at the left side of the ventricular septum. Methods and Results-Records from 28 consecutive repaired Tetralogy of Fallot patients from 2 centers who underwent VT ablation were reviewed. Ablation targeted anatomic isthmuses containing VT re-entry circuits, which were identified by 3-dimensional substrate, pace, and entrainment mapping. A left-sided approach was considered beneficial if (1) right-sided RFCA failed, (2) part of the circuit was mapped to the left side, and (3) left-sided RFCA resulted in isthmus transection and prevention of VT induction. In 4 of 28 patients (52±13 years; 75% men), inducible for 1.5 (quartiles, 1.0 -2.0) VTs (335±58 ms), left-sided RFCA was performed. In 3 patients, RFCA at aortic sites terminated VT related to a septal isthmus and prevented reinduction. In 1 patient, with prior biventricular implantable cardioverter-defibrillator, diastolic activity was recorded at the left side of the septum in proximity to the His-bundle. RFCA prevented VT reinduction with anticipated complete atrioventricular block. The left-sided approach resulted in complete procedural success (transection of anatomic isthmus and noninducibility) and freedom of VT recurrence during follow-up (20±15 months) in all patients. Right-sided RFCA failure was likely because of septal hypertrophy in 2, overlying pulmonary homograft in 1, and overlying ventricular septal defect patch in 1. Conclusions-Left

PACES/HRS expert consensus statement on the use of catheter ablation in children and patients with congenital heart disease

“…197 VT is occasionally related to a scar in an LV location or in other diseased RV myocardium. 206 Mapping and Ablation Initiation of VT with programmed stimulation allows assessment of the QRS morphology of the VT, helps confirm the diagnosis, and provides a potential assessment of the procedural endpoint of inducible VT absence. In early reports, contact mapping combined with pace mapping and entrainment mapping was performed with satisfactory results.…”

Retrograde aortic access during ventricular tachycardia ablation: Indications, techniques, and challenges

“…The bulk of research on VT ablation in congenital heart disease has focused on surgically corrected ToF. Left‐sided substrates are commonly encountered in ToF and the retrograde approach is the preferred approach for left ventricular access . ToF may be associated with multiple aortic abnormalities which may present technical challenges during retrograde access.…”

Anatomical Substrates and Ablation of Reentrant Atrial and Ventricular Tachycardias in Repaired Congenital Heart Disease

“…To Important reasons for ablation failure are hypertrophied myocardium and protection of portions of anatomical isthmuses by patch material. 81 In particular, in patients who have undergone pulmonary valve replacement (PVR) the implanted pulmonary homograft may cover parts of the infundibular septum preventing transection of anatomical isthmus 3 (see Figure 6). If ablation from the RV fails to transect the anatomical isthmuses a left-sided approach may be helpful for those anatomical isthmuses which involve the septum.…”

“…If ablation from the RV fails to transect the anatomical isthmuses a left-sided approach may be helpful for those anatomical isthmuses which involve the septum. 81 The strong association between anatomically defined isthmuses, macroreentrant VT and the inability to transect isthmus 3 after PVR may justify pre-operative mapping and preventive ablation in patients with slow conducting anatomical isthmuses who require reoperation for pulmonary valve regurgitation.…”