ABSTRACT
BACKGROUND: Adenosine triphosphate (ATP) can provoke acute reconnections after pulmonary vein isolation (PVI). This study aimed to investigate dormant conduction (DC) after ablation with second-generation cryoballoon (CB). METHODS: Two hundred sixteen patients (148 male; age 64±9 years) with atrial fibrillation (AF) were included. After a successful PVI with the CB, 20mg of ATP was administered. All patients were followed up for 425±56 days. RESULTS: Seven hundred ninety-five out of 864 (92%) PVs were successfully isolated solely by the CB. DCs were revealed in 8 (3.7%) after ATP injections. AF recurrences occurred in 2 out of 8 patients, while no AF recurrences could be documented in 6 out of 8 patients with DCs after a blanking period of 3 months (25% vs. 75%). In contrast, 29 (13.9%) patients without DCs had AF recurrences, and there was no significant difference between those with and without DCs regarding the recurrence rate of AF (p=0.38). There were no reliable predictors of DCs after the PVI with the CB. CONCLUSION: The present study demonstrated a low rate of transient PV reconnection after adenosine infusion following successful PVI with the CB. There was no reliable predictor of DCs. Further studies will be needed in order to appreciate the prognostic value of adenosine testing after successful PVI with the CB.
Subject(s)
Adenosine Triphosphate/pharmacology , Atrial Fibrillation , Catheter Ablation , Pulmonary Veins , Aged , Atrial Fibrillation/physiopathology , Atrial Fibrillation/surgery , Female , Humans , Male , Middle Aged , Prognosis , Pulmonary Veins/drug effects , Pulmonary Veins/physiopathology , Pulmonary Veins/surgery , Recurrence , Treatment OutcomeABSTRACT
BACKGROUND: Phrenic nerve (PN) palsy (PNP) is the most frequent complication of cryoballoon ablation (CBA) of atrial fibrillation (AF). The major complication of this technique seems to be right-sided PN injury (PNI) following ablation of the right pulmonary veins (PVs). We sought to assess the incidence and prognosis of left-sided PNI during CBA. METHODS: CBA was performed in 448 patients with AF. During the ablation of the left-sided PVs, the PN was paced from the left subclavian vein with a pacing output just exceeding the threshold by 10 â¼ 20%. The right and left arm 12-lead electrocardiogram electrodes were positioned 5 cm above the xiphoid process and 16 cm along the left costal margin. The amplitude of the compound motor action potentials was recorded during the CBA. RESULTS: Two thousand one hundred seventy-eight CBA applications were delivered in 1,094 left-sided PVs. PNI occurred in 29 patients (6.5%); the PN could be captured by an increasing pacing output in 21 patients (4.7%), and premature termination of the freezing was required to avoid PNP in eight patients (1.8%). The PN function recovered before discharge; however, it took 7 months for one patient to completely recovery from the PNP. CONCLUSIONS: Left-sided PNP could be provoked during a left-sided CBA procedure. Assessment of the left PN during the CBA was necessary to prevent left-sided PNP.
