What diagnostic test is used to assess for heart block?

The electrocardiogram (ECG) is the primary diagnostic test used to assess for heart block because it provides a detailed record of the electrical activity of the heart. This test can clearly show the time intervals between heartbeats, identify any abnormal conduction pathways, and detect the presence of heart block by revealing delayed or interrupted electrical signals between the atria and ventricles. In various types of heart block—such as first-degree, second-degree, or third-degree block—the ECG will demonstrate distinct patterns that can help healthcare providers determine the severity of the condition and guide treatment options.

The other diagnostic tests, while useful for assessing different aspects of cardiovascular health, do not specifically evaluate the conduction system of the heart in the same way. For example, chest X-rays are valuable for visualizing the heart and surrounding structures but will not provide information on heart electrical activity. Stress tests evaluate cardiac response to exercise and can indicate functional issues but still won't directly assess for heart block. An echocardiogram offers insight into the heart's structure and function through ultrasound imaging, yet it does not measure electrical conduction directly. Thus, the electrocardiogram remains the gold standard for diagnosing heart block.