Abstract Body (Do not enter title and authors here): Introduction:
Ventricular arrhythmias are prevalent in patients with both ischemic cardiomyopathy (ICM) and non-ischemic cardiomyopathy (NICM) and are associated with increased mortality. Multi-modality imaging may aid in characterization of Ventricular Tachycardia (VT) substrate. We evaluate the utility of pre-procedural cardiac computed tomography (CT) in predicting substrate for ventricular arrhythmias in patients with ICM and NICM within the Emory healthcare system.
Methods:
Patients who underwent VT or PVC ablation were identified via retrospective chart review from October 2022 through May 2024. Patients with ICM or NICM along with pre-procedural Cardiac CT were included.
Results:
A total of 298 ablations were reviewed. Among these, 14 patients (average age 62 ± 15 years; 64% male) had pre-procedural cardiac CT that identified potential VT or PVC substrate. Of these patients, 36% (n=5) had documented ICM, 64% (n=9) had NICM. Notably, 14% (n=2) of the CT findings showed evidence of scar, 14% (n=2) indicated subepicardial fat, and all 14 patients (100%) exhibited various wall motion abnormalities (see figure). Mapping and ablation locations were consistent with pre-procedural CT imaging in 64% (n=9) of the cases. The 36% (n=5) of mismatches were primarily found in patients undergoing ablation in papillary muscles or those with bundle branch reentry, areas that are known to be poorly visualized on CT. Conversely, all matched patients (n=9) had CT findings of wall motion abnormalities, scar, or subepicardial fat corresponding to ablation sites. 21% (n=3) of patients exhibited mid-diastolic potentials on mapping that aligned with pre-procedural CT imaging. 43% (n=6) of patients exhibited late potentials on mapping that aligned with pre-procedural CT imaging. Of note, one patient’s CT findings did not match the location of ablation though did align with late potentials on mapping.
Conclusions:
While there are no clear guidelines on obtaining pre-procedural cardiac CT for VT ablations, our single academic institution experience suggests excellent localization of VT substrate in patients with ICM and NICM by imaging. The few patients with imaging who did not correlate with ablation targets, were those with ablations in papillary muscles, valvular heart disease, or bundle branch reentry, which are challenging to visualize with CT. These results support the potential role of cardiac CT in enhancing the accuracy of VT substrate characterization.