Related Experiment Videos
Myocardial scintigraphy with 123I-labelled heptadecanoic acid in patients with unstable angina pectoris
Insights
123I-heptadecanoic acid (123I-HA) effectively detects myocardial ischemia in unstable angina patients. This imaging agent reveals distinct metabolic turnover rates, differentiating ischemic areas from infarcted regions.
Area of Science:
- Cardiology
- Nuclear Medicine
- Medical Imaging
Background:
- 123I-heptadecanoic acid (123I-HA) is used to calculate metabolic turnover rates for detecting regional myocardial ischemia.
- Previous studies established different turnover rates in stable angina versus myocardial infarction.
Purpose of the Study:
- To assess the utility of 123I-HA in identifying myocardial ischemia in patients with unstable angina.
- To compare 123I-HA turnover rates in unstable angina with those in myocardial infarction.
Main Methods:
- Twelve patients with unstable angina were studied.
- Turnover rates were derived from time-activity curves and expressed as half-time (t 1/2) in minutes.
- Imaging defects and myocardial regions were analyzed.
Main Results:
- Eight patients exhibited imaging defects in 12 myocardial regions; four patients showed no defects.
- Regions with accumulation defects displayed significantly increased t 1/2 values (45.4 ± 4.8 min) compared to normally perfused zones (29.1 ± 3.6 min).
Conclusions:
- 123I-HA can successfully identify ischemic areas of the myocardium in patients with unstable angina.
- The metabolic turnover of 123I-HA in unstable angina differs from that observed in myocardial infarction.
Abstract:
Calculation of metabolic turnover rates with 123I-heptadecanoic acid (123I-HA) can detect regional myocardial ischaemia in patients with coronary artery disease. We have previously demonstrated different turnover rates in patients with stable angina compared with myocardial infarction. Twelve patients with unstable angina have now been studied: 8 patients showed imaging defects in 12 different myocardial regions and in 4 no defects were observed. Turnover rates were derived from time-activity curves and expressed in minutes half-time (t 1/2). All 12 regions with accumulation defects showed increased t 1/2 values (45.4 +/- 4.8 min) compared to normally perfused zones (29.1 +/- 3.6 min). The results suggest that the use of 123I-HA can identify ischaemic areas of myocardium in unstable angina and that the turnover of 123I-HA is different from that already established in the areas with infarction.