Collateral nervous damages after cryoballoon pulmonary vein isolation

Various types of complications have been reported after atrial fibrillation (AF) ablation using radiofrequency energy, but those have not been well defined when using cryoballoon ablation technique. The objective of this prospective study was to assess types, incidence, and outcome of complications after cryoballoon pulmonary vein isolation (PVI).

This prospective monocentric study included 66 consecutive patients (39 males, age 57 ± 11 years) who underwent cryoballoon PVI for symptomatic paroxysmal AF. Phrenic nerve (PN) integrity was assessed by pacing from the superior vena cava during isolation of the right PVs. Before discharge, all patients were subjected to 24-hour Holter electrocardiograms, echocardiography, and esophagogastroduodenoscopy. Cardiac MRI was scheduled between 1 and 3 months postprocedure. At 3.7 ± 1.7 months after ablation, patients underwent clinical review and 24-hour Holter electrocardiograms. The mean number of cryoballoon applications was 10.0 ± 2.1 per patient and 2.5 ± 1.0 per vein. A 28 mm cryoballoon was used in 49 patients (74%) and a 23 mm cryoballoon in the remaining 17 patients (26%). Twelve complications (18%) attributing to collateral nervous damage were noticed in 9 patients: asymptomatic gastroparesis was observed in 6 patients (9%), transient PN palsy (PNP) in 5 (8%), and symptomatic inappropriate sinus tachycardia requiring beta-blocker treatment in 1 (1%). Neither cryoballoon-related esophageal ulceration nor PV stenosis was observed.

Gastroparesis and PNP could be observed in a significant number of cases after cryoballoon ablation of AF. These complications are likely due to cryo-induced damages to nervous structures surrounding the heart.