RIGHT-VENTRICULAR DYSPLASIA AS A GENERALIZED CARDIOMYOPATHY - FINDINGS ON MAGNETIC-RESONANCE-IMAGING

The aim of our study was to define cardiac morphological and functiona l abnormalities of right ventricular dysplasia by magnetic resonance i maging. Twenty-two healthy volunteers (age, 37.7 +/- 14.2 years) free of cardiac or respiratory diseases (group I) and 12 patients (age, 41. 9 +/- 15.8 years) with clinical, electrophysiological and cineangiogra phic diagnosis of right ventricular dysplasia (group II) underwent mag netic resonance imaging at 0.2 Tesla. End-diastolic diameter, trabecul ar disarray and segmental wall motion abnormalities were evaluated for the right ventricle as were adipose replacement and fractional shorte ning for both ventricles. The right ventricular end-diastolic diameter was significantly enlarged in group II (P=0.0023). Right ventricular trabecular disarray was mild in two group I subjects, and moderate in seven and massive in five group II patients. Right ventricular systoli c bulges were found in seven group II patients, aneurysms in five. Exc ellent agreement was found between magnetic resonance imaging and cine angiography for bulges, aneurysms and tricuspid regurgitation (P<0.000 1). On spin-echo images, signal hyperintensities, die to adipose repla cement, were found in 44 cardiac regions in group II: right ventricula r outflow tract (12), sub-tricuspid posterobasal region (8), right ven tricular apex (9), right ventricular anterior wall (6), interventricul ar septum (4), left ventricular lateral wall (4) left ventricular apex (1). Significant signal-to-noise ratio differences were found between group II abnormal areas and group I myocardial tissue for the right ( P<0.0001) and left ventricles (P=0.0006). Fractional shortening in the right and left ventricles were significantly, reduced in group II (P= 0.0002 and P=0.0016, respectively). Magnetic resonance imaging can be considered a very useful diagnostic tool for the detection of features typical of right ventricular dysplesia, such as adipose replacement, trabecular disarray, bulges and aneurysms and provides useful informat ion about cardiac function and regional wall motion. It indicates that left ventricular involvement occurs in a significant function of pati ents, and suggests that right ventricular dysplasia may be a generaliz ed cardiomyopathy.