Left ventriculograms of 20 patients with hypertrophic cardiomyopathy were digitised frame by frame and analysed using a contour display. Abnormalities of regional wall movement were present in 17, and included an abnormal sequence of inward movement during systole (13), regional delay in the onset of inward movement (10), and an abnormal dispersion of peak velocities (5). Diastolic wall movement was disturbed in 13, because of abnormal peak velocities in 7 and regional asynchrony in 6. Abnormal wall movement during the two isovolumic periods was rare in hypertrophic cardiomyopathy, unlike ischaemic heart disease. These disturbances may reflect underlying structural abnormalities.