Luminal esophageal temperature rise and esophageal lesion formation following remote-controlled magnetic pulmonary vein isolation.

BACKGROUND: Remote magnetic pulmonary vein isolation (PVI) demonstrates comparable success rate to manual ablation, but thermal effects on esophageal tissue remain undefined. OBJECTIVE: The purpose of this study was to evaluate the potential thermal effects on esophageal tissue during remote magnetic wide-area circumferential pulmonary vein isolation (CPVI). METHODS: Twenty-five patients (23 men, age 57 ± 10 years) in the magnetic navigation system (MNS) group and 25 control subjects (15 men, age 61 ± 12 years) with drug-refractory paroxysmal or persistent atrial fibrillation underwent CPVI. A magnetic 3.5-mm irrigated-tip catheter (NaviStar ThermoCool RMT, Biosense Webster) and a nonmagnetic 3.5-mm irrigated-tip catheter (NaviStar ThermoCool, Biosense Webster) were used in the MNS and control group, respectively. A temperature probe (SensiTherm, St. Jude Medical), containing 3 thermocouples was placed in close proximity to the ablation site monitoring luminal esophageal temperature (LET). LET changes did not guide therapy. Postprocedural esophagogastroduodenoscopy (EGD) was performed in all patients. RESULTS: Successful CPVI was achieved in all patients. No esophageal lesions, minimal lesions, or ulcerations were found in 16 of 25 (64%), 7 of 25 (28%), and 2 of 25 (8%) in the MNS group and in 14 of 25 (56%), 10 of 25 (40%), and 1 of 25 (4%) patients in the control group, respectively. No atrioesophageal fistula occurred. Mean maximum LET in the magnetic group was 43.7°C ± 3.7°C compared to 45.4°C ± 3.5°C in the manual control group (P = .09). CONCLUSION: Remote magnetic PVI is associated with significant rise in LET and development of thermal esophageal lesions. In the MNS group, higher LET recordings were more likely to cause esophageal injury, whereas this association was not seen in the manual group despite a tendency toward higher mean maximum LET recordings.

Cryoballoon temperature predicts acute pulmonary vein isolation.

BACKGROUND: Cryoballoon pulmonary vein isolation (PVI) currently requires a long cryoballoon application (CBA) time of 240 to 300 seconds, thus repeated ineffective CBA prolongs procedure duration. We hypothesized that cryoballoon temperature (CBT) may be used to discriminate between effective and ineffective CBA during freezing. OBJECTIVE: This study sought to evaluate CBT as a predictor of CBA efficiency. METHODS: Sixty-six patients with atrial fibrillation underwent PVI using the single big (28 mm) cryoballoon technique. CBT was continuously recorded. After each CBA (300 seconds), a Lasso catheter (Biosense Webster, Inc., Diamond Bar, California) was placed into the target pulmonary vein (PV) to determine whether electrical PV disconnection was present. Only the first CBA at each PV was analyzed to avoid cumulative effects. RESULTS: The CBT was lower during CBA at superior compared with inferior PVs. When individual CBAs were grouped according to successful/failed PVI, CBT was lower for those CBAs that resulted in successful PVI at all time points analyzed. To test the performance of CBT to predict failed CBA, receiver-operator curves were constructed. A minimal CBT of ≥ -42°C/ -39°C (superior/inferior PVs) predicted failed PVI with 73%/92% specificity (area under the curve 0.82/0.81); positive predictive value (PPV) 74%/74%. A minimal CBT of < -51°C was invariably associated with PVI. After 120 seconds of freezing, a CBT of ≥ -36°C/ -33°C (superior/inferior PVs) predicted failed PVI with 97%/95% specificity (area under the curve 0.82/0.76); PPV 82%/80%. CONCLUSION: Balloon temperature predicts successful target PVI during cryoablation and may serve in the early identification of noneffective balloon applications.

Esophageal temperature change and esophageal thermal lesions after pulmonary vein isolation using the novel endoscopic ablation system.

BACKGROUND: Pulmonary vein isolation (PVI) is an established treatment option for paroxysmal atrial fibrillation. Recently, a novel endoscopic ablation system (EAS) was introduced. The incidence and severity of ablation-induced esophageal thermal lesions (ETLs) are unknown. OBJECTIVE: The purpose of this study was to investigate the incidence and severity of ablation-induced ETLs. METHODS: This prospective analysis compared two groups: group A underwent EAS-based PVI, and group B received PVI using radio frequency current (RFC). If esophageal temperature measured via an endoluminal temperature probe exceeded 38.5°C, energy application was stopped immediately. Endoscopy was performed 2 days postablation. RESULTS: Forty patients (20 female, mean age 56 ± 10 years) were treated with the EAS system (group A). In 20 patients (seven female, mean age 63 ± 9 years) RFC-based PVI was performed (group B). Esophageal endoscopy was performed 2.1 ± 0.8 (group A) and 2.8 ± 1.2 days postablation (group B), respectively. In 7/40 patients (18%) in group A, thermal lesions (four thermal ulcerations, three minimal thermal lesions) were detected. In group B, 3/20 patients (15%) displayed thermal lesions (three minimal thermal lesions). All thermal lesions resolved upon repeat endoscopy performed 8 ± 6 (group A) and 5 ± 1 days (group B) after initial endoscopy. CONCLUSION: In the EAS group, ETLs were found in 18% of patients, as compared with in 15% in the RFC group. In patients with ETLs, ulcerations were found in 57% in the EAS group, as compared with 0% in the RFC group. This may indicate that the quality of thermal lesions is more severe in the EAS group. Further investigation is required.

Catheter ablation of atrial fibrillation in patients with persistent left superior vena cava is associated with major intraprocedural complications.

BACKGROUND: A persistent left superior vena cava (PLSVC) is an uncommon cardiac anomaly. OBJECTIVE: The purpose of this study was to assess the complication rate and procedural outcome in patients with PLSVC who were referred for catheter ablation of atrial fibrillation (AF). METHODS: Between September 2006 and February 2009, seven patients referred for circumferential pulmonary vein (PV) isolation (PVI) demonstrated a PLSVC. PVI was confirmed by spiral catheter recording within the respective PVs. Ablation within the PLSVC was performed using an irrigated-tip catheter (energy settings 20 W, 43°C, flow rate 17 mL/min) or, alternatively, a cryoballoon catheter (28 mm balloon, 300-second energy application). Patients were analyzed according to procedural outcome and rate of complications. RESULTS: Among seven patients (three female, mean age 57 ± 8 years, two paroxysmal, five persistent AF, structural/congenital heart disease present in three patients, mean left atrial size 43 ± 6 mm), 14 ablation procedures were performed. Two major complications (left phrenic nerve injury and cardiac tamponade) occurred in two of four patients undergoing PLSVC ablation. Of four of seven patients undergoing PLSVC ablation, two patients needed one and one patient needed two redo PLSVC ablation procedures. The first-time procedural success rate was 29%, while the overall success rate reached 86% after a median follow-up period of 621 (339-1,289) days. CONCLUSION: In patients with ectopic activity from a PLSVC, the ablative strategy should include isolation of the PLSVC as a procedural endpoint, although multiple ablation procedures may be necessary to achieve stable sinus rhythm. Contrary to previous reports, complications are common if the PLSVC is targeted for ablation.

Unexpected high incidence of esophageal injury following pulmonary vein isolation using robotic navigation.

INTRODUCTION: Robotic navigation (RN) is a novel technology for pulmonary vein isolation (PVI). We investigated the incidence of thermal esophageal injury using RN with commonly used power settings in comparison to manual PVI procedures. methods: Thirty-nine patients underwent circumferential PVI using a 3.5-mm irrigated-tip-catheter. In the manual (n = 25) and the RN(1) group (n = 4) power was limited to 30 W (17 mL/min flow, maximal temperature 43 degrees C, max. 30 sec/spot) at the posterior left atrial (LA) wall. In RN-based procedures, ablation was performed with a contact force of 10-40 g. The operator was blinded to the esophageal temperature (T(eso)). In the RN(2) group ablation power along the posterior LA wall was reduced to 20 W and ablation terminated at T(eso) of 41 degrees C. Endoscopy was carried out 2 days post-ablation. RESULTS: PVI was achieved in all patients. In the manual group no esophageal lesions, minimal lesions, or ulcerations were found in 15 of 25 (60%), 7 of 25 (28%), and 3 of 25 (12%) patients, respectively. All patients in the RN(1) group had an ulceration and one developed esophageal perforation. A covered stent was placed 14 days post-PVI and removed at day 81. In the RN(2) group, only a single minimal lesion was found. CONCLUSIONS: A high incidence of thermal esophageal injury including a perforation was noted following robotic PVI using 30 W along the posterior LA wall. During RN-based PVI procedures esophageal temperature monitoring is advocated. Reduction of ablation power to 20 W and termination of energy delivery at T(eso) of 41 degrees C significantly reduced the risk of esophageal injury.

Right ventricular rapid pacing in catheter ablation of atrial fibrillation: a novel application for cryoballoon pulmonary vein isolation.

BACKGROUND: Cryoballoon ablation (Arctic Front, Cryocath) represents a novel technology for pulmonary vein isolation (PVI). The initial phase of a freeze is crucial for cryolesion formation which is determined by local temperature depending on blood flow. We investigated the impact of right ventricular rapid pacing (RVRP) on temperature kinetics in patients (pts) with paroxysmal atrial fibrillation (PAF). METHODS AND RESULTS: Right ventricular rapid pacing was performed from the RV apex. Absolute minimal temperature (MT, degrees C), temperature slopes [time (s) to 80% MT; dT/dt), area under the curve (AUC) and arterial blood pressure (ABP, mmHg) were compared (group I: with RVRP vs. group II: without RVRP). RVRP (mean duration 55 +/- 7 s) was performed in 11 consecutive PAF pts (41 PVs, age 58 +/- 9 years, LA size 44 +/- 6 mm, normal ejection fraction). Only freezes with identical balloon positions were analyzed (11/41 PVs). RVRP (cycle length 333 +/- 3 ms) induced a significant drop in ABP (group I: 45 +/- 3 mmHg vs. group II: 100 +/- 18 mmHg, p < 0.001). MT was not different between group I and group II (-45.0 +/- 4.4 vs. -44.3 +/- 3.4 degrees C, p = 0.46), whereas slope (38.0 +/- 4.6 s vs. 51.6 +/- 14.4 s, p = 0.0034) and AUC (1090 +/- 4.6 vs. 1181 +/- 111.2, p = 0.02) was significantly changed. In one pt, a ventricular tachycardia was induced. PVI was achieved in 41/41 PVs. CONCLUSION: Right ventricular rapid pacing significantly accelerates cryoballoon cooling during the initial phase of a freeze possibly suggesting improved cryolesions.

Pulmonary vein isolation after left-sided pneumonectomy: technically challenging but feasible and instructive.

We present a technically challenging case of pulmonary vein isolation (PVI) after complete left-sided pneumonectomy, resulting in uncommon cardiac rotation. Wide area circumferential PVI after pneumonectomy is technically challenging but feasible in experienced centres. Correct identification of the PV ostia is crucial before ablation.

The 'single big cryoballoon' technique for acute pulmonary vein isolation in patients with paroxysmal atrial fibrillation: a prospective observational single centre study.

AIMS: Cryothermal energy (CTE) ablation via a balloon catheter (Arctic Front, Cryocath) represents a novel technology for pulmonary vein isolation (PVI). However, balloon-based PVI approaches are associated with phrenic nerve palsy (PNP). We investigated whether 'single big cryoballoon'-deployed CTE lesions can (i) achieve acute electrical PVI without left atrium (LA) imaging and (ii) avoid PNP in patients with paroxysmal atrial fibrillation (PAF). METHODS AND RESULTS: After double transseptal punctures, one Lasso catheter and a big 28 mm cryoballoon catheter using a steerable sheath were inserted into the LA. PV angiography and ostial Lasso recordings from all PVs were obtained. Selective PV angiography was used to evaluate balloon to LA-PV junction contact. CTE ablation lasted 300 s, and the PN was paced during freezing at right-sided PVs. Twenty-seven patients (19 males, mean age: 56 +/- 9 years, LA size: 42 +/- 5 mm) with PAF (mean duration: 6.6 +/- 5.7 years) were included. PVI was achieved in 97/99 PVs (98%). Median (Q(1); Q(3)) procedural, balloon, and fluoroscopy times were 220 min (190; 245), 130 min (90; 170), and 50 min (42; 69), respectively. Three transient PNP occurred after distal PV ablations. No PV stenosis occurred. Total median (Q(1); Q(3)) follow-up time was 271 days (147; 356), and 19 of 27 patients (70%) remained in sinus rhythm (3-month blanking period). CONCLUSION: Using the single big cryoballoon technique, almost all PVs (98%) could be electrically isolated without LA imaging and may reduce the incidence of PNP as long as distal ablation inside the septal PVs is avoided.