Fehmi Keçe

Chapter 2 52 2.8 Prevention of Complications Knowledge of all potential complications is important for prevention. Technical advances may help to improve safety. Three-dimensional electro-anatomical mapping and image integration canminimize radiation exposure. Careful procedural planning, close cooperation of different medical specialties (e.g. in hybrid AF treatment) and patient monitoring can further reduce complications (133). 2.8.1 Pericardial Effusion/Tamponade For prevention of cardiac tamponade, limiting of radiofrequency power to 30-40 watts in the anterior wall and 20-30 watts in the posterior wall has been applied in most studies (table 1a/1b). Previous studies demonstrated that power limitation from 45-60 to ≤ 42 Watt in linear lesions during AF ablation limited the incidence of cardiac tamponade (134). With the introduction of force sensing catheters, RF power adjustment according to CF parameters became possible, however optimal values remain to be established (135). 2.8.2 Stroke/TIA Trans-oesophageal echocardiography, computed tomography or cardiacmagnetic resonance imaging may be used to exclude the presence of a left atrial thrombus (4). Symptomatic cerebral thromboembolic events are relatively rare (0.8%) (136). Independent risk factors are a CHADS2 score ≥2 and a history of stroke (137). Accurate sheath management can reduce the risk of air embolism (incidence <1%). Continued oral anticoagulation (INR ≥ 2) during the procedure and maintenance of an adequate ACT (>300) should be considered to impact catheter thrombogenicity and the risk for (asymptomatic) cerebral embolism (138). A meta-analysis of 13 studies comparing non-vitamin K antagonists (NOAC) with vitamin-k antagonists (including 3 RCT) could demonstrate that NOACs are safe and effective, but adequately-powered randomized controlled trials are required to confirm these results (139). 2.8.3 Phrenic Nerve Palsy Superior caval vein phrenic nerve pacing with palpation of diaphragmatic excursions may allow discontinuation of ablation before permanent injury (140). Diaphragmatic compound motor action potential (CMAP) monitoring is a relatively new technique to prevent PNP (141). To measure the CMAP signal, the left and right arm electrocardiogram leads are placed respectively 5 cm above the xiphoid and 16 cm along the right costal margin. Peak- to-peak measurement is performed of the CMAP-signal with each phrenic nerve capture