Detecting Coronary Heart Disease: Common Diagnostic Methods
Coronary heart disease (CHD) occurs when the coronary arteries become narrowed or blocked, reducing blood flow to the heart. Early detection is crucial for effective treatment and improved outcomes. Below are the most common diagnostic tools used to identify coronary heart disease:
1. Electrocardiogram (ECG)
An electrocardiogram is often the first test used to assess heart function and detect abnormalities. During an ECG, electrodes are placed on the skin to record the heart's electrical activity. Changes in the ST segment — such as horizontal or downsloping ST depression — may indicate myocardial ischemia (reduced blood flow to the heart muscle). If the ST segment is elevated and shows dynamic changes over time, it could suggest a heart attack.
Since ischemia may not always be present during a standard ECG, ambulatory ECG monitoring (Holter monitoring) may be used to record heart activity over a 24- to 48-hour period. This allows doctors to detect transient ischemic episodes that occur during daily activities or exercise.
Exercise Stress Test
For patients experiencing exertional angina (chest pain during physical activity), a treadmill stress test can be particularly useful. This test evaluates how the heart responds to physical exertion and may reveal signs of ischemia that are not evident at rest.
2. Coronary Angiography
Coronary angiography is considered the gold standard for diagnosing coronary artery disease. It involves inserting a catheter into a blood vessel — usually in the wrist or groin — and guiding it to the heart. A contrast dye is then injected into the coronary arteries, allowing them to be visualized under X-ray imaging.
This diagnostic method provides detailed images of the coronary arteries and helps identify the location and severity of any blockages. However, because it is an invasive procedure, it carries some risks and is typically reserved for patients with a high likelihood of significant coronary disease.
3. Coronary CT Angiography (CTA)
Coronary computed tomography angiography (CTA) offers a non-invasive alternative to traditional angiography. In this procedure, contrast dye is injected into a vein in the arm, and a high-resolution CT scanner captures detailed images of the coronary arteries.
CTA is particularly useful for ruling out significant blockages in patients with low to intermediate risk of CHD. It is less invasive than conventional angiography and provides valuable information about plaque buildup and arterial narrowing.
4. Echocardiography
An echocardiogram uses sound waves to create images of the heart's structure and function. It is especially helpful in identifying regional wall motion abnormalities — a sign of previous heart damage or reduced blood flow to parts of the heart muscle.
In patients with suspected ischemia, echocardiography can detect abnormal movement in specific areas of the heart wall, which may indicate coronary artery disease. For those with a history of old myocardial infarction, the test can reveal thinning of the heart muscle, absence of movement, or even paradoxical motion in the affected regions, surrounded by areas of increased motion — all of which support a diagnosis of CHD.