Nuclear Cardiology Stress Test

A nuclear cardiology stress test, also known as a myocardial perfusion scan or radionuclide stress test, is a diagnostic procedure used to evaluate the blood flow to the heart muscle during physical activity or stress.

Procedure Overview

The test involves injecting a small amount of radioactive tracer into the bloodstream, which is then imaged using a gamma camera. The tracer accumulates in the heart muscle in proportion to blood flow, allowing for visualization of areas with reduced blood flow.

Pre-Test Preparation

• Patients are typically asked to avoid eating or drinking for several hours before the test
• Caffeine and nicotine should be avoided for at least 24 hours prior to the test
• Beta blockers and other medications may need to be withheld for a period of time before the test, as directed by the physician

Test Protocol

The test typically involves two parts:

1. Resting scan: The patient is injected with the radioactive tracer while at rest, and images are taken of the heart using a gamma camera.
2. Stress scan: The patient undergoes physical stress, typically on a treadmill or stationary bike, to increase heart rate and blood pressure. The radioactive tracer is then injected again, and images are taken immediately after exercise.

Image Acquisition and Analysis

The gamma camera takes images of the heart from multiple angles, which are then reconstructed into three-dimensional images. A computer analyzes the images to assess blood flow to the heart muscle, identifying areas with reduced uptake of the tracer, which may indicate:

• Coronary artery disease
• Myocardial infarction (heart attack)
• Cardiomyopathy

Risks and Side Effects

The test is generally safe, but may involve:

• Mild discomfort during injection of the tracer
• Temporary increase in heart rate and blood pressure during stress testing
• Exposure to small amounts of radiation (equivalent to approximately 1-2 years of natural background radiation)

Interpretation and Results

The results of the test are interpreted by a cardiologist or nuclear medicine specialist, who will assess the images for signs of reduced blood flow or other abnormalities. The results may be used to:

• Diagnose coronary artery disease or other heart conditions
• Monitor the effectiveness of treatment
• Guide further testing or intervention, such as angiography or revascularization procedures