A cardiac stress test is an examination, in which the impact of effort on the functioning of the heart is investigated. The purpose is to detect diseases of the heart, which are triggered or worsened by effort. The recording of the study takes place in the form of an electrocardiogram (ECG).
Performing a cardiac stress test usually involves the detection of an oxygen shortage in the cardiac muscle as a result of reduced blood flow, due to narrowing(s) in the coronary arteries. At rest, the blood flow is often sufficient, but on exertion the blood flow cannot increase enough, causing oxygen shortage and symptoms, such as angina pectoris. Other reasons for performing a cardiac stress test are determination of the capacity for physical exercise and assessment of rhythm disorders of the heart.
In a cardiac stress test, the electrical activity of the heart during increased activity is measured. The cardiac function laboratory assistant puts caps onto the chest and arms of the patient. These caps are connected with wires to a monitor. With this device, the heart rhythm is monitored during the test and is examined whether changes can be seen on the ECG. Blood pressure is measured every three minutes during the examination. Therefore, the patient is given a cuff around the arm.
During the study, the patient sits on a type of home trainer, the exercise bicycle. The effort on the bike is gradually built up. Every two minutes, the bicycle automatically increases resistance and it gets more strenuous. It’s the intention that the patient can last as long as possible, so that the body must make a considerable effort. The cardiologist wants to know the condition of the heart. Therefore, heart rate and blood pressure are recorded. In case of severe fatigue or problems, the test is stopped.
The examination, including preparations and follow-up, lasts about thirty minutes. The results of the cardiac stress test are, depending on who has requested the study, usually already available on the same day.