The stress ECG differs from a stress echocardiogram (stress echo). A stress echo uses ultrasound and the ECG to assess the health of your heart. The sensitivity, specificity and predictive value (how good is the test at finding a problem) of Stress ECG is less than Stress Echo for assessment of ischaemic heart disease (any significant narrowing of your coronary arteries) but it has its own indications and usefulness.
As your body works harder during exercise, it requires more oxygen, so the heart must pump more blood. If there is any blockage in the arteries supplying blood to your heart muscle, it will cause reduction in oxygen supply and ECG will change. This means that the test is “positive”.
There may be an arrhythmia (electrical problem or rhythm problem) precipitated by exercise, and this test helps to unmask that.
When do you need a stress ECG?
There are several reasons your doctor may request a Stress ECG including:
Exclusion of ischaemic heart disease (significant coronary artery blockage)
Fitness to drive (commercial heavy vehicle licence or private licence)
Fitness for joining a gym or a specific exercise program
Fitness for surgery from a cardiac perspective
Exclusion of sinister exertional arrhythmia
Assess for a normal chronotropic response to exercise (normal physiological increase in heart rate during exercise and reduction in heart rate with recovery)