A novel approach to treat atrial tachycardia by catheter ablation in patients after orthotopic biatrial heart transplantation: The L-line.

BACKGROUND

Atrial tachycardia (AT) is commonly observed after orthotopic biatrial heart transplantation (O-BA-HTx). Its clinical presentation, relationship to atrial anastomoses, and electrophysiologic characteristics remain controversial. Novel radiofrequency-guided catheter ablation (RFCA) strategies using electroanatomical mapping and myocardial substrate characterization have emerged, but data on their efficacy in this patient group are scarce.

OBJECTIVE

This study aimed to evaluate the efficacy and safety of a novel RFCA strategy for AT in O-BA-HTx patients and assess long-term arrhythmia-free survival.

METHODS

Overall, 37 consecutive O-BA-HTx patients with therapy-refractory AT underwent prospectively an RFCA between 2017 and 2024. Procedural parameters, acute and long-term outcomes, and complications were assessed.

RESULTS

The cohort (mean age 56.9 ± 16.3 years, 83.8% male) underwent RFCA of AT. Electrophysiologic diagnoses included: The L-line approach, which combines cavotricuspid isthmus and RA-lateral line ablation, was responsible for AT termination in 92.1% (n = 34) of cases. All procedures were performed without any major complications. The median follow-up was 26 months (interquartile range 19-60), and only 2 patients (5.3%) experienced AT recurrence. Remarkably, achieving freedom from AT was associated with freedom from atrial fibrillation, highlighting the effectiveness of addressing AT as a trigger for atrial fibrillation.

CONCLUSION

The novel L-Line approach is a safe, effective, and reproducible approach for AT ablation in O-BA-HTx patients, with favorable long-term arrhythmia-free survival.