What does the ECG reading mean?
During a stress test, the electrocardiogram (ECG) is the machine that records the electrical activity of the heart as it beats (see Figure 2). In a normal heart, the ECG will record a distinct, regular pattern of electrical impulses. However, this electrical pattern can change in certain ways that are characteristic of specific types of heart problems. For example, problems with the heart’s natural pacemaker may cause the heart to beat irregularly (an arrhythmia). This will appear as an irregular pattern on the ECG recording. A heart that beats too quickly or too slowly will also show up on the ECG. Similarly, a heart attack and heart disease also cause certain distinct, abnormal electrical patterns that can be recognized on the ECG. When a person exercises on a treadmill while connected to an electrocardiogram, the physical exertion causes the heart to work harder. This increases the chance of detecting an abnormal ECG pattern that will lead to an accurate diagnosis or evaluation. Alt
