Search

Accurate delineation of the variable left atrial anatomy is of utmost importance during anatomically based ablation procedures for atrial fibrillation targeting the pulmonary veins and possibly other structures of the atria. Intracardiac echocardiography allows real-time visualisation of the left atrium and adjacent structures and thus facilitates precise guidance of catheter-based ablation of atrial fibrillation. In patients with abnormal anatomy of the atria and/or the interatrial septum, intracardiac ultrasound might be especially valuable to guide transseptal access. Software algorithms like CARTOSound (Biosense Webster, Diamond Bar, USA) offer the opportunity to reconstruct multiple two-dimensional ultrasound fans generated by intracardiac echocardiography to a three-dimensional object which can be merged to a computed tomography or magnetic resonance imaging reconstruction of the left atrium. Intracardiac ultrasound reduces dwell time of catheters in the left atrium, fluoroscopy, and procedural time and is invaluable concerning early identification of potential adverse events. The application of intracardiac echocardiography has the great capability to improve success rates of catheter-based ablation procedures.

Objective. Despite the use of anticoagulation during left atrial (LA) ablation procedures, ischemic cerebrovascular accidents (CVAs) are recognized as a serious complication. Heparin is usually given after safe transseptal access has been obtained, resulting in a short unprotected dwell time of catheters within the LA, which may account for CVAs. We investigated the frequency of CVAs and LA thrombus formation as detected by intracardiac ultrasound (ICE) depending on the timing of heparin administration. Methods and Results. Sixty LA ablation procedures with the use of ICE were performed in 55 patients. Patients were grouped by heparin administration after (Group I, 𝑛=13) and before (Group II, 𝑛=47) transseptal access. Group I patients were younger (56.6±13.7 versus 65.9±9.9 years, 𝑃=.01); other clinical and echocardiographic characteristics did not differ between groups. Early thrombus formation was observed in 2 (15.4%) of group I patients as compared to 0% of group II patients (𝑃=.04). One CVA (2.1%) occurred in one group II patient without prior thrombus detection, and none occurred in group I patients (𝑃=ns). Conclusion. Early administration of heparin reduces the risk of early intracardiac thrombus formation during LA ablation procedures. This did not result in reduced rate of CVAs.