The resting ECG looks at the electrical activity of the heart when the patient is lying comfortably and therefore doesn’t test the heart under load. The exercise test allows the cardiologist to see how the heart performs under load. Although the exercise test has some limitations it can be useful in screening, assessing exercise capacity, in the investigation of patients with chest pain and for some other indications such as heart rhythm problems. Exercise is usually on either a treadmill or exercise bike and performed with ECG electrodes connected. The blood pressure is measured frequently during the test.
Cardiopulmonary Exercise Test
This test is similar to the exercise ECG in that involves the same exercise with continuous ECG monitoring and blood pressure measurements. The important difference is that the exercise ECG is focussed principally on the heart. The cardiopulmonary Exercise Test (CPET) is more ’holistic’. It examines multiple causes of exertional breathlessness, be they due to the heart, the lungs or indeed problems of general conditioning and can often differentiate between these. CPET can also be used to evaluate fitness levels in athletes, and to assess patients capacity to tolerate surgical operations. CPET achieves these aims by measuring the oxygen consumption and expired carbon dioxide levels during exercise.
All test results should be treated with caution and interpreted in the context of a clinical assessment.