Evaluation of myocardial viability in hypertrophic cardiomyopathy by 123I-BMIPP myocardial imaging

Sixteen patients with hypertrophic cardiomyopathy underwent both thallium-201 (Tl-201) and I-123 β-methyl iodophenyl pentadecanoic acid (I-123 BMIPP) myocardial imaging. Uptake patterns of both types of imaging in regional myocardium were compared visually and quantitatively. On viual assessment, there was a marked discrepancy in myocardial uptake between Tl-201 and I-123 BMIPP: the degree of I-123 BMIPP uptake was more markedly decreased than Tl-201 uptake, and decreased uptake of I-123 BMIPP was observed in 50% of the cases of increased Tl-201 uptake. Severity score of I-123 BMIPP, as calculated on SPECT, inversely correlated with thickness of the ventricular septum and left ventricular ejection fraction, as compared with that of Tl-201. I-123 BMIPP imaging was capable of detecting myocardial degeneration earlier than Tl-201 imaging. It proved to aid in evaluating myocardial viability and pathophysiology in hypertrophic cardiomyopathy. (N.K.)