Single-Center Experience of a Novel Catheter with a Multipolar Grid-Patterned Electrode Configuration for High-Density Mapping and Catheter Ablation of Atrial and Ventricular Arrhythmias in Patients with Congenital Heart Disease

Objectives: Catheter ablation of arrhythmias in patients with congenital heart disease (CHD) remains challenging and time consuming. A novel diagnostic catheter with a multipolar grid-patterned electrode configuration for high-density mapping may reduce mapping time and enhance ablation success. Here, we describe our experience with this catheter in patients with CHD.

Methods: Patients with CHD referred for catheter ablation between April 2018 and September 2020 using a 3D nonfluoroscopic mapping system were enrolled. Primary success was defined as noninducibility of atrial or ventricular tachycardia.

Result: A total of 26 consecutive patients (median age: 26 years, range: 7–65 years; female n = 13) underwent 28 ablation procedures with initial high-density mapping. The underlying heart defects were s/p ASD-closure (n = 4), pulmonary valve commissurotomy (n = 1), the repaired tetralogy of Fallot (n = 2), repaired PA/VSD (n = 1), biventricular repair of DORV (n = 1), tricuspid and pulmonary valve replacement in PA/IVS (n = 1), mitral valve replacement (n = 1), atrial switch procedure in dTGA (n = 4), Fontan's palliation (tricuspid atresia: n = 5, DILV: n = 3, HLHS: n = 2, and DORV: n = 1). Previous ablation had been performed in 12 patients. During mapping of respective cardiac chambers, the mean of total collected points was 32,789 (range: 375–249,831) and the mean of total used points was 3,758 (range: 250–13,910). Mean mapping and fluoroscopy time were 58.4 (range: 3–178) and 12.5 (range: 0–43) minutes, respectively. There were 58 atrial tachycardia (AT) substrates in 23 patients (median: 2.5, range: 1–5 per patient) and six ventricular tachycardia (VT) substrates in three patients (median: 2, range: 1–3). Acute success was achieved in 24 of 28 procedures (85%) with successful ablation of 54 of 58 (93%) AT and five of six of VT (83%) substrates. No complications occurred. During a mean follow-up time of 18 months (range: 1–29 months), three patients (12.5%) had arrhythmia recurrence.

Conclusion: In this series, high-density mapping allowed elucidation of the tachycardia mechanism in all patients with a high primary ablation success, a limited radiation exposure and a low rate of arrhythmia recurrence.

Publication History

Article published online:
21 February 2021