Abstract 2675: Epicardial Fat Mapping Using Multi-detector Computed Tomography to Assist Transepicardial Ventricular Arrhythmia Ablation
Background: A number of ventricular tachycardic circuits are epicardial and are amendable to percutaneous transepicardial ablation. However, the presence of >1–3mm of epicardial fat can interfere with accurate substrate mapping and prevent successful creation of ablation lesions. A better understanding of epicardial fat distribution would improve procedure planning, time and effectiveness.
Methods: We examined the epicardial fat distribution in 20 patients who underwent multi-detector computed tomography (MDCT) using a 64-slice scanner. Multiplanar reconstructions were obtained during systole and diastole at five levels through the ventricular short axis and in a four chamber view. Epicardial fat thickness was measured across multiple wall segments in each view.
Results: Epicardial fat was found to be thicker in perivascular segments (6.7±2.9mm) as compared to non-vascular segments (2.8±0.9mm). Within the perivascular segments, thickness of pericardial fat increased from the apex of the ventricles (5.2±1.2mm) to the base (10.2±4.6mm). The right ventricular wall had thicker epicardial fat (3.2±0.8mm) as compared to the left ventricular wall (2.1±0.5mm). In perivascular segments, epicardial fat was greater during systole (8.5±3.2mm) as compared to diastole (6.7±2.9mm). In non-vascular segments, epicardial fat was also greater during systole (4.2±1.4mm) as compared to diastole (2.8±0.9mm).
Conclusion: Epicardial fat can be accurately mapped using MDCT and shows a maximum thickness in perivascular segments and at the base of the ventricles. Importantly, a 50% increase in fat thickness was found in systole vs. diastole. This characterization can provide the electrophysiologist with a topographic roadmap to better plan the ablation approach and increase procedural success.