Safety aspects of deep sedation during catheter ablation of atrial fibrillation.

BACKGROUND: The combination of intravenous propofol and midazolam is frequently used to provide unconscious sedation during catheter ablation of atrial fibrillation (AF), but only a very few reports are available on the influence of prolonged propofol infusion on arterial blood gas, blood pressure, and anesthesia-associated complications during ablation of AF. The purpose of this study was to assess tolerance and safety of unconscious sedation with intravenous propofol and midazolam during catheter ablation of AF. METHODS: A total of 316 consecutive patients (age 59 ± 10 years, 68% men) presenting to our center for catheter ablation of symptomatic AF were enrolled prospectively. A total number of 424 procedures were performed under unconscious sedation with propofol and midazolam. SaO(2), electrocardiogram, arterial blood pressure, and arterial blood gases were monitored throughout the procedure. RESULTS: Mean procedure duration was 235 ± 48 minutes. Patients received 1.125 ± 684 mg propofol, 9.5 ± 3 midazolam, and 1.963 ± 813 mL NaCl infusion. Complications during the procedure were identified in eight patients (2.5%, one × coronary air embolization, one × myocardial infarction, four × pericardial effusion, two × pericardial tamponade). All eight patients were symptomatic (distress, report of pain); none of the complications was attributable to unconscious sedation itself. CONCLUSION: Unconscious sedation with propofol and midazolam in AF ablation procedures lasting 3-5 hours did not result in severe changes of vital parameters or serum electrolytes. Anesthesia-associated problems were not observed. Propofol and midazolam can be safely used during catheter ablation of AF.

Findings and outcome of fluoroscopic visualization of the oesophageal course during catheter ablation of atrial fibrillation.

AIMS: The close topographic relationship between the left atrial posterior wall (LAPW) and the oesophagus creates a potential hazard of thermal lesions to the oesophagus during radiofrequency (RF) catheter ablation of atrial fibrillation (AF). The purpose of the study was to describe topographic relation of the oesophagus behind the left atrium in the ablation situation, and to evaluate the clinical outcome of subsequent modifications to the strategy using continuous real-time fluoroscopic visualization of the oesophageal course. METHODS AND RESULTS: In 214 consecutive patients, a gastric tube (GT) was inserted before circumferential pulmonary vein isolation (CPVI) for the treatment of paroxysmal (n= 160) or persistent (n= 54) AF. In the real-time mapping situation at the LAPW, the tissue interface between catheter tip and oesophagus lumen measured only 2.9 ± 1.9 mm, and 2.5 ± 1.2 mm at the level of the upper and lower pulmonary vein (PV) ostia, respectively. Modifications of the intended antral CPVI approach due to an oesophageal course close to the left or right PV ostia (in 76.6% of patients) were associated with reduced success rate (sustained sinus rhythm) after one (54.9 vs. 72.0%, P = 0.03), or 1-3 ablation procedures (85.4 vs. 96.0%, P = 0.04) during a mean follow-up of 13 ± 10 months. CONCLUSION: Continuous real-time fluoroscopic visualization using a GT emphasizes the very small distance of the catheter tip and oesophageal lumen that may be present in the real-ablation situation and may help to avoid RF lesion application in close proximity to the oesophagus. However, accordant modification of AF ablation strategy may reduce efficacy of the procedure.