Koya Ozawa MD, Presenter: Nothing to Disclose

Nobusada Funabashi MD, PhD, Abstract Co-Author: Nothing to Disclose

Hiroyuki Takaoka MD, PhD, Abstract Co-Author: Nothing to Disclose

Masae Uehara MD, Abstract Co-Author: Nothing to Disclose

Yoshio Kobayashi, Abstract Co-Author: Nothing to Disclose

If specific organized substrates of ventricular fibrillation (VF) are identified, they may provide important information for prevention of sudden cardiac death. 320-slice CT (Aquilion One, Toshiba Medical) can acquire heart images for 1 heart beat. Even if arrhythmia occurs during acquisition, clear heart images can be obtained. We compared 320-slice CT heart images in subjects with VF with those who had sustained and non-sustained ventricular tachycardia (VT).

Ninety-four subjects were studied: 18 with VF, mean age, 57±16 years; 18 with sustained VT, mean age, 60±20 years; and 58 with non-sustained VT, mean age, 59±15 years. If there was a contrast defect in myocardium in the early phase, late phase acquisition was added at 6 min after contrast injection, and if abnormal late enhancement was observed in the corresponding site, we diagnosed myocardial fibrosis (MF).

No significant differences among groups were noted except for the ratio of complete right bundle branch block (Table). On CT, there were no significant differences in percentage of coronary arteries with >50% stenosis among the 3 groups, but MF was significantly more common in the VF group (67%, all myocardial fibrosis was in left ventricle) than in the non-sustained VT group (28%, p<0.05). Myocardial fatty change was significantly more common in the sustained VT group (56%, half of myocardial fatty change was in right ventricle) than in the VF (22%, p<0.05) and non-sustained VT groups (29%, p<0.05).

MF and fatty change may be substrates of VF or sustained VT. 320-slice CT can evaluate coronary arteries and myocardium in subjects with arrhythmia and even in those with implantable cardioverter defibrillators, which cannot be done with magnetic resonance imaging.

If there is myocardial fibrosis and fatty change in 320-slice CT, occurrence of critical ventricular arrhythmia should be considered.

Ozawa, K, Funabashi, N, Takaoka, H, Uehara, M, Kobayashi, Y, Myocardial Fibrosis and Fatty Change Based on 320-Slice CT Heart Images May Be Organized Substrates of Critical Ventricular Arrhythmia in Subjects with Ventricular Fibrillation Compared with Sustained and Non-Sustained Ventricular Tachycardia.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12043554.html