https://orcid.org/0000-0002-1202-4232
A 62-year-old male Afro-Caribbean former sprinter presented with exertional syncope. Electrocardiography revealed lateral epsilon waves, QRS fractionation, and non-sustained ventricular tachycardia at 278 b.p.m. Echocardiography demonstrated severe global left ventricular (LV) systolic dysfunction with thinned akinetic mid-anterolateral, mid-inferolateral, and apical lateral segments. Coronary angiography confirmed unobstructed epicardial arteries.
Gadolinium contrast-enhanced cardiovascular magnetic resonance imaging (CMR) at 1.5 T demonstrated a dilated and severely impaired LV, with wall thinning and wall-motion abnormalities corresponding with echocardiography (Supplementary data online, Videos S I–IV). Parametric native T1 mapping using a standard, modified Look-Locker (MOLLI) sequence (Top panel) demonstrated elevated native T1 values transmurally mid-inferolaterally (1492 ± 80 ms, blue arrow) consistent with advanced fibrosis, and subendocardially mid-anterolaterally. Very low T1 values were present (516 ± 90 ms, red arrow) subepicardially and mid-myocardially at the mid-anterolateral and apical lateral segments suggestive of fatty infiltration. Segments with T1 elevation demonstrated late gadolinium enhancement (LGE) (Middle panel) consistent with fibrosis. Segments with low native T1 showed extreme LGE with a signal intensity akin to fat. Findings were consistent with fibrofatty deposition rather than fibrotic scarring alone, characteristic of arrhythmogenic ventricular cardiomyopathy (AVC).
There are no established diagnostic criteria for LV AVC (ALVC). However, ALVC was diagnosed on revised task force criteria for right ventricular AVC. Absent LV hypertrophy was incongruous with Fabry's disease, which was excluded by a normal serum alpha-galactosidase assay.
This case highlights the importance of contemporary CMR parametric mapping in non-invasively diagnosing this rare potentially lethal AVC phenotype, eliminating procedural risks of myocardial biopsy, and differentiating from common mimics such as infarction with fatty metaplasia.
Top: Pre-contrast 1.5 T Modified Look-Looker MOLLI native T1 CMR mapping sequence at mid-ventricular level [red arrow: subepicardial mid-anterolateral low native T1 values (516 ms) in keeping with fat infiltration; blue arrow: elevated T1 values (1492 ms) in keeping with fibrosis transmurally at the mid-inferolateral segment and subendocardially at the mid-anterolateral segment; white arrow: remote unaffected myocardium with normal T1 values (941 ms)]. Middle: Corresponding short-axis mid-LV late gadolinium enhancement (LGE) image (red arrow: subepicardial mid-anterolateral region of low native T1 demonstrates extreme late hyperenhancement with a signal intensity akin to fat; blue arrow: late hyperenhancement transmurally at the mid-inferolateral segment and subendocardially at the mid-anterolateral segment; white arrow: remote unaffected myocardium with no late hyperenhancement). Bottom: Corresponding steady-state free precession (SSFP) cine image (blue arrow: myocardium correlating with late hyperenhancement (LGE) transmurally at the mid-inferolateral segment and subendocardially at the mid-anterolateral segment).
Supplementary data are available at European Heart Journal - Cardiovascular Imaging online.
