Multimodal Image Processing Software to Guide Cardiac Ablation Therapy

Depending on potential contra-indications to iodine-enhanced computed tomography. It will be performed using the usual method on a 64-slice dual energy scanner. Data will be acquired after the injection of 120 mL iodine contrast media. Contrast will be injected at the rate of 4 mL/s without additional saline flush in order to obtain homogeneous enhancement of the 4 cardiac chambers, there by simplifying subsequent segmentation. The objective will be to obtain a 3-dimensional imaging of cardiac structures

Depending on potential contra-indications to gadolinium-enhanced magnetic resonance. It will be performed on the 1.5 Tesla clinical device associated to MUSIC equipment (Magnetom Avanto, Siemens, Erlangen, Germany). Myocardial fibrosis will be imaged using a free-breathing delayed-enhancement method initially developed for atrial imaging. The method uses a 3-dimensional, inversion recovery-prepared, ECG-gated and respiratory-navigated Turbo Fast Low Angle Shot sequence with fat saturation. Acquisition will be initiated 15 minutes after the injection of a double-dose of gadolinium-based contrast media.

Only in patients with a contra-indication to magnetic resonance imaging. It will be performed on a PET/CT 600 device. Acquisition will be preceded by a standard metabolic preparation for 18 fluoro-deoxy-glucose viability imaging. The objective will be to obtain a 3-dimensional imaging of ventricular scar.

It will be obtained using a 252-electrode vest. The position of each electrode with respect to epicardium will be assessed at multi-detector computed tomography prior to mapping. In patients referred for ventricular arrhythmia, body surface mapping will aim at recording the clinical arrhythmia whenever possible. In patients referred for atrial arrhythmia, body surface mapping will aim at recording atrial fibrillation.

Ventricular procedures will be performed endocardially using trans-septal or retro-aortic approach, potentially combined with sub-xiphoid epicardial access. Atrial procedures will be performed endocardially using trans-septal approach to access the left atrium. Bi-atrial bipolar contact mapping will be performed at high density during atrial fibrillation prior to ablation.