Magnetic resonance investigations in Brugada syndrome reveal unexpectedly high rate of structural abnormalities

Recent data suggest that sub-clinical structural abnormalities may be part of the Brugada syndrome (BrS) phenotype, a disease traditionally thought to occur in the structurally normal heart. In this study, we carried out detailed assessment of cardiac morphology and function using cardiac magnetic resonance imaging (CMRI). Thirty consecutive patients with BrS were compared with 30 sex- (26/4 male/female), body surface area- (+/- 0.2 m(2)), and age-matched (+/- 5 years) normal volunteers. CMRI exam included long- and short-axis ECG-gated breath-hold morphological T1-TSE sequences for fatty infiltration and cine-SSFP sequences for kinetic assessment. Fatty infiltration was not found in any subject. Patients with BrS compared with normal subjects showed higher incidence of mild right ventricle (RV) wall-motion abnormalities [15 (50%) vs. 5 (17%) subjects (P = 0.006) with reduced radial fractional shortening in more than two segments], reduction of outflow tract ejection fraction (49 +/- 11% vs. 55 +/- 10%; P = 0.032), enlargement of the inflow tract diameter (46 +/- 4 vs. 41 +/- 5 mm, P < 0.001 in short-axis; 46 +/- 4 vs. 42 +/- 5 mm, P = 0.001 in four-chamber long-axis view) and area (22 +/- 2 vs. 20 +/- 3 cm(2); P = 0.050), and of global RV end-systolic volume (34 +/- 10 vs. 30 +/- 6 mL/m(2); P = 0.031) but comparable outflow tract dimensions, global RV end-diastolic volume, left ventricle parameters, and atria areas. CMRI detects a high prevalence of mild structural changes of the RV, and suggests further pathophysiological complexity in BrS. Prospective studies to assess the long-term evolution of such abnormalities are warranted.