Late Enhancement and Myocardial Perfusion in Hypertrophic Cardiomyopathy (Comparison between Groups)

Background: The magnetic resonance imaging (MRI) is an effective method to study hypertrophic cardiomyopathy (HCM). Objective: To evaluate, using MRI, the parameters of systolic function, perfusion and myocardial viability in patients with HCM, comparing the groups with and without obstruction of the left ventricular outflow tract. Methods: Twenty-one patients with a diagnosis of HCM underwent the assessment of myocardial function, viability and perfusion under stress and at rest through MRI. Results: The ventricular segments most severely impaired by hypertrophy were those of the septal region. The obstructive group presented segmental myocardial thickening distribution similar to the non-obstructive group, but with higher means than the first group. The mean ejection fraction of the patients in the obstructive group was higher than in the non-obstructive group, whereas the means of the end systolic and diastolic volumes were lower in the obstructive group. There was a positive correlation between the ventricular segmental thickening and the late enhancement segmental mass. The stress induction resulted in an increase in the number of segments with perfusion alterations and this alteration was more evident in the obstructive group. Conclusion: The thickest ventricular segments are the septal ones. The hypertrophic regions are associated to a greater extension of late enhancement. There was a positive correlation between the areas of ventricular hypertrophy and altered myocardial perfusion and these findings were more evident in the obstructive group. (Arq Bras Cardiol 2009; 93(3) : 396-402)