Specific organized substrates of ventricular fibrillation: Comparison of 320-slice CT heart images in non-ischemic ventricular fibrillation subjects with non-ischemic sustained and non-sustained ventricular tachycardia subjects

Abstract

If specific organized substrates of ventricular-fibrillation (VF) are identified, they may provide important-information for prevention of sudden-cardiac-death. To identify specific organized substrates of VF, we compared 320-slice CT heart images in non-ischemic VF subjects with non-ischemic sustained and non-sustained ventricular-tachycardia (VT) subjects. Retrospective analysis of a total of 103 subjects who had VF (17 subjects; age, 59 ± 16 years), sustained VT (20 subjects; 62 ± 19 years), or non-sustained VT (66 subjects; 60 ± 15 years) underwent 320-slice CT (Aquilion one). After excluding 26 ischemic subjects with >50% stenosis in any coronary arteries on CT, myocardial infarction, or coronary vasospastic angina, a total of 77 non-ischemic subjects (12 VF subjects; age, 58 ± 18 years), (13 sustained VT subjects; 55 ± 20 years) or (52 non-sustained VT subjects; 58 ± 15 years) were analyzed. On CT, myocardial abnormal-late-enhancement was significantly more frequent in the VF group (75%, all myocardial abnormal-late-enhancement in left-ventricle) than in the sustained VT group (31%) and the non-sustained VT group (35%) (both P<0.01). Myocardial fatty change was significantly more frequent in the sustained VT group (54%) than in the VF group (17%) and the non-sustained VT group (12%) (both P<0.01). Final diagnoses of the non-ischemic VF and sustained groups included four subjects in each case with normal cardiac structure on transthoracic echocardiogram; the former included two subjects who had abnormal-late-enhancement on CT without specific ECG findings. Myocardial abnormal-late-enhancement and fatty change on CT may be substrates of VF or sustained VT in non-ischemic subjects. 320-slice CT can evaluate both coronary arteries and myocardium.