Cold pressor test in detection of coronary heart-disease and cardiomyopathy using technetium-99m gated blood-pool imaging
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Cold pressor scintigraphy effectively detects coronary artery disease by showing reduced left ventricular ejection fraction. This cardiac imaging technique is more sensitive than exercise ECG for identifying severe coronary artery disease.
Area of Science:
- Cardiology
- Nuclear Medicine
- Diagnostic Imaging
Background:
- Coronary artery disease (CAD) diagnosis often relies on detecting impaired cardiac function.
- Non-invasive imaging modalities are crucial for assessing myocardial function and detecting CAD.
- The cold pressor test can unmask latent cardiac dysfunction.
Purpose of the Study:
- To evaluate the efficacy of gated cardiac blood-pool scintigraphy during cold pressor stimulation for detecting coronary artery disease.
- To compare the sensitivity of this method with single-lead exercise electrocardiography in patients with severe CAD.
Main Methods:
- 50 normotensive subjects (22 controls, 24 with CAD, 4 with cardiomyopathy) underwent gated cardiac blood-pool scintigraphy.
- Scintigraphy was performed at rest and during cold pressor stimulation.
- Left ventricular ejection fraction and regional wall motion were analyzed.
Main Results:
- Control subjects showed stable or increased left ventricular ejection fraction and normal wall motion.
- Patients with CAD or cardiomyopathy exhibited a significant decrease in left ventricular ejection fraction and abnormal wall motion.
- Cold pressor scintigraphy demonstrated higher sensitivity (p=0.03) than exercise ECG for detecting severe CAD without prior myocardial infarction.
Conclusions:
- Cold pressor gated cardiac blood-pool scintigraphy is a sensitive tool for identifying cardiac dysfunction in patients with coronary artery disease.
- This imaging technique can detect severe CAD even in the absence of angina or previous myocardial infarction.
- It offers improved diagnostic capability compared to exercise electrocardiography for specific patient groups.
Abstract:
50 normotensive subjects (22 controls with no cardiac disease, 24 patients with coronary heart-disease, and 4 with early cardiomyopathy) were investigated with gated cardiac blood-pool scintigraphy before and during cold pressor stimulation. The controls had no change or a significant rise (p less than 0.005) in left ventricular ejection fraction and preserved normal myocardial-wall motion, whereas patients with coronary-artery disease or cardiomyopathy had a significant fall (p less than 0.001) in left ventricular ejection fraction and many developed abnormal regional wall motion despite the absence of angina pectoris. Cold pressor gated cardiac blood-pool studies were more sensitive than single-lead exercise electrocardiography (p = 0.03) in the detection of patients with severe coronary-artery disease without previous myocardial infarction.