Electroanatomic mapping and radiofrequency catheter ablation of atrial fibrillation or atrial tachycardia in patients with pulmonary hypertension. Ancillary analysis

Abstract

Abstract Background Atrial fibrillation (AF) and related atrial tachycardias (ATs) are common arrhythmias in patients with pulmonary hypertension (PH). They are currently assessed in a multicentre randomized trial investigating extensive radiofrequency catheter ablation of the arrhythmogenic substrate on top of selective ablation of clinical arrhythmia alone. Purpose Irrespective of the randomization scheme, we compared clinical and procedural characteristics in patients with AF versus those with right-sided ATs. Methods Out of 74 patients with combined post- and pre-capillary or isolated pre-capillary PH, two study subgroups were composed: AF group included 40 patients and AT group included 31 patients: 24 with typical atrial flutter (AFL) and 7 with other right-sided ATs (2 upper loop reentry ATs, 2 focal ATs from coronary sinus ostium, 1 focal AT from terminal crest, and 2 polymorphic ATs from high right atrium). Three patients with inducible AV nodal reentrant tachycardia were excluded from this analysis. Biatrial electroanatomic mapping was performed in all patients. The data are presented as medians (interquartile range) and compared by the Mann-Whitney U test. Results The clinical and procedural characteristics of AF and AT groups are shown in Table. Cycle length (CL) of both induced and spontaneous AFL was 302 (267; 324) ms. Non-CTI-dependent ATs had CL 425 (350; 480) ms. In patients with AF, the dominant CL was 183 (152; 221) and 191 (154; 210) ms in right and left atrial appendage, respectively. In the whole cohort, pulmonary vein isolation was done in 49 (66%), left atrial substrate ablated in 23 (31%), cavotricuspid isthmus block achieved in 46 (62%), superior vena cava isolation completed in 28 (39%), intercaval line ablated in 26 (36%), and right atrial substrate or focal activity ablated in 8 (11%) cases. The procedure was technically successful in 72 (97%) patients. Conclusion Patients with right-sided ATs had expectedly more dilated right atrium. This was not, however, associated with a higher prevalence of right atrial low-voltage areas. Left atrial electroanatomic remodelling in AF patients was concordant with that frequently observed in non-PH patients with AF. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Ministry of Health of the Czech Republic.