Stress Test (TMT)

A stress test is performed to evaluate the load-taking capacity of your heart, which in turn gives an idea about the blood supply to heart.

It is performed if an individual shows symptoms of coronary artery disease, which include:

• Chest pain
• Difficulty in breathing, after exertion (eg, climbing up stairs or walking a short distance)
• Fatigue
• Dizziness
• Anxiety
• Vague chest discomfort
• Altered sleep patterns

It is also performed as a routine test in individuals who are at risk of developing coronary artery disease. Common risk factors for CAD include:

• Prolonged hypertension
• Dyslipidaemia (altered cholesterol levels)
• Prolonged diabetes
• Obesity
• Smoking
• Alcohol
• Stressful lifestyle
• Inactivity or lack of physical exercising
• Family history of heart-related conditions (Read more: Heart disease causes)
• Older age (above 60 years)

Additionally, a stress test is helpful in determining the effectiveness of cardiac procedures performed to improve circulation in the coronary artery.

A stress test requires certain preparations for obtaining an accurate test report:

• Avoid the intake of vitamins, herbal or over-the-counter (OTC) medicines a day prior to the test
• Avoid the use of antihypertensives on the day of the test (it can be taken after the test is performed)
• Avoid the intake of food or water for about 2 to 4 hours before the test
• Avoid smoking on the test day

A set of electrodes will be placed on your chest (in a similar pattern as it is placed during electrocardiography). Initially, you will be asked to walk slowly on a treadmill, and the speed is increased gradually. Next, the treadmill will be slightly inclined to provide a small elevation. You may then be asked to breathe in a tube for 2-3 minutes.

The test takes about 7 to 10 minutes. Results from the electrodes (as seen on monitor) are recorded in real-time. Heart rate, breathing rate and blood pressure reading are also noted.

 A stress test carries a minimal risk of breathlessness, increased blood pressure or increased heart rate but otherwise, it is quite safe.

Normal results: Normal results are indicated by little or no fatigue after the test and normal ECG recording. They also suggest an absence of coronary artery disease.

Abnormal results: A positive stress test suggests a very high possibility of blockage in the coronary artery, which indicates the presence of coronary artery disease.

A negative or improved report in a person who has had a positive result previously and is undergoing therapy for coronary artery disease indicates a positive response to the therapy.

An individual with a positive stress test gets a hint on the amount of load (exertion) his/her heart can take up, thereby determining a safe level of exercising.

If the results of a stress test are poor or unfavourable, it is followed by a cardiac catheterisation (coronary angiography) procedure to evaluate the amount of blockage in the coronary artery.

Disclaimer: All results must be clinically correlated with the patient’s complaints to make a complete and accurate diagnosis. The above information is provided from a purely educational point of view and is in no way a substitute for medical advice by a qualified doctor.