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[Thallium-201 myocardial perfusion imaging during adenosine-induced coronary vasodilation in patients with ischemic
1First Department of Internal Medicine, Yamagata University School of Medicine.
Insights
This study shows that thallium-201 (201Tl) myocardial perfusion imaging with adenosine infusion is a safe and effective method for diagnosing coronary artery disease. The imaging technique demonstrated high sensitivity and specificity in detecting perfusion defects.
Area of Science:
- Cardiology
- Nuclear Medicine
- Diagnostic Imaging
Background:
- Coronary artery disease (CAD) diagnosis requires accurate and non-invasive imaging techniques.
- Myocardial perfusion imaging (MPI) using thallium-201 (201Tl) is a valuable tool for assessing cardiac blood flow.
- Pharmacological stress agents like adenosine can be used to induce hyperemia in MPI when exercise stress is not feasible.
Observation:
- 55 patients with suspected CAD underwent 201Tl MPI during intravenous adenosine infusion.
- Adenosine infusion induced transient hemodynamic changes (slight BP reduction, HR increase) and mild side effects (chest pain, headache, AV block).
- All observed effects were transient and well-tolerated after discontinuing adenosine.
Findings:
- 201Tl MPI during adenosine infusion achieved 100% sensitivity and 88% specificity in detecting CAD.
- Semi-quantitative assessment of 201Tl uptake identified perfusion defects.
- The procedure was deemed safe and useful for evaluating ischemic heart disease.
Implications:
- Adenosine-infused 201Tl MPI is a reliable diagnostic strategy for patients with suspected CAD.
- This imaging modality offers high diagnostic accuracy, aiding in timely clinical decision-making.
- The safety profile supports its routine use in clinical practice for evaluating ischemic heart disease.
Abstract:
201Tl myocardial perfusion imaging during adenosine infusion was performed in consecutive 55 patients with suspected coronary artery disease. Adenosine was infused intravenously at a rate of 0.14 mg/kg/min for 6 minutes and a dose of 111 MBq of 201Tl was administered in a separate vein at the end of third minute of infusion. Myocardial SPECT imaging was begun 5 minutes and 3 hours after the end of adenosine infusion. For evaluating the presence of perfusion defects, 2 short axis images at the basal and apical levels and a vertical long axis image at the mid left ventricle were used. The regions with decreased 201Tl uptake were assessed semi-quantitatively. Adenosine infusion caused a slight reduction in systolic blood pressure and an increase in heart rate. The rate pressure products increased slightly (9314 +/- 2377 vs. 10360 +/- 2148, p < 0.001). Chest pain (24%) and headache (13%) were the frequent side effects. The second-degree atrioventricular block was developed in 11 of 55 (20%) patients. All symptoms and hemodynamic changes were well tolerated and disappeared within 1 or 2 minutes after discontinuing adenosine infusion. The sensitivity and specificity for the detection of patients with coronary artery disease were 100% (31/31) and 88% (7/8), respectively. 201Tl myocardial imaging during adenosine infusion was considered to be safe and useful for evaluating the patients with ischemic heart disease.