Are wall thickness channels defined by computed tomography predictive of isthmuses of postinfarction ventricular tachycardia?

International audience; ObjectiveThis study sought to determine whether 3-dimensionally-reconstructed computed tomography (CT) channels correlate with electrophysiological isthmuses during ventricular tachycardia (VT).MethodsWe retrospectively studied 9 postinfarction patients (aged 57 ± 15 years, 1 female) with 10 complete VT activation maps (cycle length 429 ± 77ms) created using high-resolution mapping. Three-dimensionally-reconstructed WT maps from CT were merged with the activation map during sinus rhythm (SR) and VT. The relationship between WT and electrophysiological characteristics was analyzed.ResultsA total of 41 CT channels were identified (median 4 per patient), of median (range) length 21.2 mm (17.3–36.8 mm), width 9.0 mm (6.7–16.5 mm), and area 1.49 cm2(1.00–1.75 cm2). WT in the channel was significantly thicker in the center than in the edge (median 2.4 mm vs 1.5 mm, P < .0001). Of 3163 (2493–5960) mapping points in SR, 382 (191–1115) local abnormal ventricular activities (LAVAs) were identified. One patient had a maximal proportion of LAVAs in 3–4 mm, 3 patients in 2–3 mm, 2 in 1–2 mm, and 2 in 0–1 mm. The VT isthmuses of all 10 VTs corresponded with 1–4 CT channels. Twenty-one of the 41 CT channels (51.2%) corresponded to a VT isthmus (entrance, mid, or exit). Electrophysiological VT isthmuses were more likely to be associated with CT channels that were longer (P = .04, odds ratio [OR] 1.05/mm), thinner (but not less than 1 mm) (P = .03, OR 0.36/mm), or parallel to the mitral annulus (P = .07, OR 3.93).ConclusionVT isthmuses were always found in CT channels (100% sensitivity), and half of CT channels hosted VT isthmuses (PPV 51%). Longer and thinner (but >1 mm) CT channels were significantly associated with VT isthmuses.