Functional description of the left ventricle in patients with volume overload, pressure overload, and myocardial disease using cine magnetic resonance imaging.

Cine magnetic resonance imaging (MRI) is a three-dimensional imaging technique with sufficient temporal resolution to provide quantitation of left ventricular (LV) dimensions and function. It can be used to describe the three-dimensional geometrical and functional characteristics of various cardiac disease states. Accordingly, the purpose of the study was to noninvasively characterize LV function with cine MRI using LV mass, systolic wall stress, ejection fraction, and fractional wall thickening, and to compare these functional determinants among three major cardiac disease states. Patients were selected from echocardiographic criteria and specific history of disease and divided into the following groups: compensated moderate to severe aortic regurgitation; compensated LV hypertrophy caused by systemic hypertension; and dilated congestive cardiomyopathy. Normal subjects without evidence of heart disease were studied for comparison. Cine MRI was performed at 1.5 Tesla in the short-axis plane. Wall stress was calculated from MRI, along with blood pressure recordings and carotid pulse tracings, according to the Laplacian expression. The end-diastolic volume to LV mass ratio distinguished between concentric and eccentric LV hypertrophy. Peak-systolic wall stress was increased in volume overload lesions and myocardial disease and significantly different (P less than .01) compared with pressure overload lesions and normal subjects. Ejection fraction was significantly decreased (P less than .01) in myocardial disease compared with volume and pressure overload lesions and normal subjects. Among these disease states, LV mass was not different but was significantly higher in all (P less than .01) compared with normal subjects. Fractional wall thickening was increased in pressure overload lesions. Thus, the increase in LV mass in volume overload lesions and primary myocardial disease is not adequate to prevent an increase in wall stress, whereas LV mass increased sufficiently in pressure overload lesions to normalize systolic wall stress. Cine MRI can be used to noninvasively describe the three-dimensional geometry and functional state of the heart in various pathological conditions and might be used to monitor therapeutic effects.