Exercising to the point of or going beyond the number of beats per minute determined in the heart rate stress test is not recommended. This type of exertion causes the heart to go into fibrillation, a state where the heart cannot move normally and the blood is not pumped efficiently through the body. Exceeding the number determined from the heart rate stress test may have serious medical consequences, including possibly death.
Individuals undergoing the heart rate stress test in a healthcare setting should immediately tell an attendant if chest pain is experienced during the procedure.
The heart rate stress test involves exercising while the heart's activity is monitored by an electrocardiogram (ECG). Small, circular pads called electrodes are painlessly placed on the body. The electrodes monitor the electrical activity of the heart and report this data to a machine through a cord.
The individual then begins exercising, usually on a treadmill, while the ECG records changes in the heart's activity. During the test, the difficulty of exercise is slowly increased until the patient reaches a target heart rate, is too tired to continue the exercise, or until the ECG detects certain changes in the heart's patterns. The highest number of beats recorded by the patient's heart during the minute before stopping the test is then recorded.
A heart rate stress test may reveal crucial information about functioning of the heart. The test may offer hints that a patient has a blocked artery that the heart is not properly pumping blood, or that sections of the heart are no longer capable of contracting. The test, if performed two or more times, can also help tell doctors if a particular treatment is helping to improve a patient's heart disorder.