Which diagnostic test evaluates blood flow in coronary arteries during exercise?

The Thallium Stress Test is specifically designed to evaluate blood flow in the coronary arteries during periods of physical exertion, such as exercise. This test involves the injection of thallium, a radioactive substance, which allows for imaging of the heart and its blood supply under stress conditions. As the patient exercises, the test measures the heart's ability to receive sufficient blood flow. Areas that may not receive adequate blood supply will show reduced or no uptake of thallium, indicating potential blockages in the coronary arteries.

The other options, while important diagnostic tools, serve different purposes. An echocardiogram assesses heart structure and function using ultrasound, but does not specifically measure blood flow in the same manner as the thallium stress test. An electrocardiogram records the electrical activity of the heart but does not provide direct measurements of blood flow. Cardiac catheterization is invasive and allows for examination of the coronary arteries, but it is typically performed in a controlled environment rather than during exercise. The thallium stress test is thus the most appropriate choice for evaluating coronary blood flow during exercise.