Cardiac Manifestations of Alström Syndrome: Echocardiographic Findings

Abstract

Alström syndrome is an extremely rare autosomal recessive genetic disorder characterized by infantile-onset cardiomyopathy (CMP), blindness, hearing impairment/loss, and obesity. Prior reports have demonstrated that the dilated CMP of Alström syndrome occurs in about 62% of patients with this syndrome. To date, there have been no reports examining the echocardiographic features of Alström-related heart disease. Eleven patients diagnosed with Alström syndrome who underwent one or more transthoracic echocardiograms from 1994 to 2003 were retrospectively evaluated. A total of 16 transthoracic echocardiograms were comprehensively reviewed with an emphasis on chamber sizes, wall thickness, left ventricular (LV) and right ventricular (RV) systolic function, and valve function. Four of 11 patients (36%) had evidence of global LV systolic dysfunction (quantitative ejection fraction [EF] range 9%-29%). Three of these 4 patients also had severe generalized RV systolic dysfunction, whereas one had normal RV systolic function. LV and RV dilation was present in 3 of 4. All patients with low EF had an apically tethered mitral valve closure pattern although only one of 4 had more than mild mitral regurgitation. Although 3 of 4 patients with low EF had an apically tethered tricuspid valve closure pattern, none had more than mild tricuspid regurgitation. Reduced EF was not associated with regional wall-motion abnormalities. Three of 11 patients (27%) overall and two of 4 of the patients with low EF (50%) had pericardial effusions. The Alström CMP in this cohort of patients was typically dilated and nonsegmental with predominantly biventricular involvement. It was infrequently associated with myocardial hypertrophy. Apically tethered mitral and tricuspid valve closure patterns were visualized, although severe functional valvular insufficiency was not present. LV and left atrial dilation was observed in a number of patients without reduced EF, and may be an early stage in the development of the CMP.