What is the most definitive diagnostic procedure for angina?

Coronary angiography is the most definitive diagnostic procedure for angina because it directly visualizes the coronary arteries, allowing for the identification of any blockages or significant narrowing that may be causing ischemia and thus angina symptoms. This imaging technique involves the injection of contrast dye into the coronary arteries, followed by X-ray imaging to observe blood flow and any arterial lesions.

While other diagnostic procedures such as stress tests and coronary computed tomography angiography (CCTA) are useful for assessing cardiac function and creating a preliminary assessment of coronary artery disease, they do not provide the same level of definitive information about the coronary anatomy and potential obstructions as coronary angiography does. Similarly, an echocardiogram can assess heart function and structural abnormalities, but it does not specifically visualize the coronary vessels and hence cannot definitively diagnose angina due to coronary artery disease.

In summary, coronary angiography is considered the gold standard for diagnosing angina because it allows for precise localization of lesions and helps guide potential further interventions, such as angioplasty or bypass surgery if necessary.