Myocardial imaging and metabolic studies with [17-123I]iodoheptadecanoic acid in patients with idiopathic congestive cardiomyopathy.

In twenty patients with primary congestive cardiomyopathy (COCM) the patterns of accumulation and washout of the fatty acid analogue [17-123I]iodoheptadecanoic acid (I-123 HA) were studied. In contrast to patients with ischemic heart disease, where reduced I-123 HA accumulation was correlated with stenosis of the main coronary arteries, thus usually involving larger wall segments, the patients with COCM concentrated I-123 HA heterogeneously in small spotty segments throughout the entire left-ventricular myocardium. The regional washout half-times varied between 15.1 and 116.2 min. It seems that in patients with severe COCM the elimination half-times are more prolonged than in early stages of the disease. There was no correlation between the regional uptake and the elimination half-times. Sequential myocardial imaging with I-123 HA appears useful for noninvasively diagnosis of COCM.