Stress Test (TMT)
Usually patients who have coronary blocks in the artery may have a heart condition, but they hardly exhibit any symptoms of it. In fact even the EKG test results may not appear abnormal. On the other hand there are patients who do have a heart condition with considerably credible symptoms. Both these types of patients could probably benefit from taking the stress test. Typically a cardiac stress test is what is used in cardiology to test the ability the heart to react to outside sources of stress in a controlled medical atmosphere. The reaction to stress is produced either by exercise or drug stimulation. The stress test compares the circulation of blood in the heart when the patient is resting and when he is under optimum physical pressure. There are various types of stress tests but the most common of them is the Treadmill stress test.
The stress test is usually used to determine whether the patient is suffering from ischemic heart condition and for determining a patient’s condition after he/she has suffered a heart attack. A stress test specifically the ones that utilize exercise help to show extreme shortness in breathing, discomfort in the chest, dizziness and sudden weakening that indicate some underlying heart condition. It is also used to check the efficiency of the medications for heart diseases like angina and ischemia and also to recognize abnormal rhythm of the heart.
The preparation for the stress test will depend on the type of stress test being conducted on the patient. A good meal before the test could lead to nausea. Generally before the exercise stress test the patient is asked not to eat or drink anything but water for four hours. The patient should not drink any beverage with caffeine for twelve hours before the test. He/she must stop all medications for the heart on the day the test is being done, unless specifically instructed by the doctor.
For diabetics who are scheduled for a stress test, people taking insulin should ask their doctor how much is to be injected on the day of the test, and for those on pills usually the medication is only taken after the completion of the stress test. One should wear comfortable clothes and soft walking shoes or sneakers.
A nurse or technician will place ten sticky patches that are the electrodes on the chest. These patches are attached to wires that carry the electrical activity of the heart to the monitor and recorder of the EKG/ECG machine. Before the patient starts the test, the EKG will record his heart activity on paper. This is what is known as the Resting EKG. More recordings will be made during the test with the doctor paying specific attention to any changes that may be recorded.
As mentioned earlier the equipment like the preparation will depend on the kind of stress test being taken. For a regular stress test the equipment used is atypical treadmill, though in some places the stress test is conducted using a stationery bicycle. These equipments also feature connections to the EKG monitor and a paper recorder, as well as a blood pressure cuff. Though the dangers of cardiac stress tests are extremely low, as the test is conducted on patients who are suspected to have a heart condition, practically all labs are ready with emergency medication and resuscitative mechanisms.
How Does The Procedure Work?
Usually people with suspected heart conditions may not necessarily exhibit major symptoms and even the ECG/EKG results may not show much variation. Nevertheless the symptoms may be unleashed when the heart is exposed to strenuous exercise. During the exercise the good arteries in the heart dilate more than those that may have blocks. This uneven dilation makes more blood to be provided to the heart by arteries that do not have blocks, while the blocked or narrowed arteries supply limited blood to their areas delivery. This lowered flow of blood makes the muscles in those areas thirst for more blood during the stress test, creating symptoms like chest pain, or shortness of breath. The EKG will also record distinguishing variations.
How Is A Stress Test Performed?
A stress test generally takes up to 90 minutes from beginning to end. The actual exercising part of the test takes only 20 minutes. The patient is brought to the test room where the technician or nurse records his/her heart rate and blood pressure at rest. The electrodes that have been placed on the patient’s chest are connected to wires that are linked to the EKG/ECG machine. There is a 12 lead EKG that will be recorded on paper. Every lead placed on the body records different areas of the heart. There are three leads that are connected to the Treadmill monitor.
The treadmill is switched on at a rather slow ‘warm-up’ speed and gradually the incline of the treadmill is increased every three minutes. This is a pre-set programme, which regulates the exact speed and incline of the treadmill. Every three minutes are called stages.
During the stress test the patient’s blood pressure is recorded at the second minute in every stage, but the recordings could be more frequent if necessary. The patient’s EKG is recorded both on paper and on the monitor, and the doctor constantly monitors the blood pressure, heart rate, and any alterations in the pattern of the EKG looking for irregularities if any. If the patient develops any sort of uneasiness the test could be stopped before the target heart rate is achieved.
Experience During And After The Procedure
The stress test is not a risky procedure and patients generally stand the stress well. Of course they may feel fatigue because that have to undergo the stress of the exercise, but otherwise things are normal. Once the test has been completed, the patient is usually advised to gradually decrease the intensity of his activity over a period of many minutes.
Benefits And Risks Of Stress Test
Stress tests are quite safe and will help the doctor in diagnosing a heart problem and determine what and how much of activity is safe for a patient.
The risks are minimal with only one out of a thousand patients experiencing problems that may result in hospitalization. There is a small danger of the patient suffering a heart attack during the stress test.
The value of stress tests have always been limited for determining heart conditions like atherosclerosis which is a condition that causes the thickening of the walls of the arteries. In addition it does not identify Atheroma or vulnerable plaques.