What is a Stress Test?

A stress test, also known as a treadmill test or exercise test, can be likened to an ECG done with physical activity. This involves the use of a treadmill or stationary bike to examine how well your heart handles work or physical stress. While you are physically active, electrodes are placed around your chest and limbs to measure your heart’s electrical activity.

What is a Stress Test for?

The exercise stress test monitors your heart rhythm, blood pressure, and breathing as you exercise. When you exercise, your heart will have to pump faster and harder to meet the body’s increased oxygen requirement. This may show blood flow problems that are often not visible in a resting ECG test. It also helps doctors discern what kind and level of exercise are appropriate for the patient.

What are its common uses?

The stress test is often carried out to:

• Evaluation of chest pain and shortness of breath
• Find the best treatment plan for the patient
• Evaluate the effectiveness of medications/treatments
• Diagnose the severity of cardiovascular conditions
• Diagnose irregular heart rhythms (arrhythmia)
• Check your heart’s condition before surgery

Who is a Stress Test recommended for?

Your cardiologist can recommend a stress test if they suspect:

• Coronary Artery Disease (CAD)

When arteries that supply the heart with blood, oxygen and nutrients become narrow or blocked

• Heart rhythm problems (arrhythmias)

When electrical signals that coordinate the heart don't work properly, causing the heart to beat too fast, too slow or irregularly.

As mentioned earlier, it is also carried out by your cardiologist to discern the best route of treatment for heart disorders and to check the condition of your heart before surgery.

It is also done to assess the disease’s progression and to assess the effectiveness of treatment plans. The test can also be done to evaluate a person’s capacity before they start a vigorous exercise programme.

Who should not undergo a Stress Test?

The test is not recommended to be used as a screening tool for those without symptoms or risk factors for coronary artery diseases. That said, it can be part of your annual check-up if you or your family have a history of heart conditions. It depends on your current condition and medical history so it is best to discuss with your doctor to see if the stress test would be necessary for you.

There are also a few contraindications for the exercise stress test. Your doctor may not recommend the stress test if you have:

• History of recent heart attack (myocardial infarction) or heart failure
• High risk of angina (chest pain due to reduced blood flow to the heart)
• Symptomatic severe aortic stenosis (narrowing of the aortic valve)

Other relative considerations include:

• Severe high blood pressure
• Uncontrolled arrhythmia (irregular heart rhythm)
• Electrolyte abnormalities

If you are unable to walk or undergo the exercise, your cardiologist may instead give you medication that would mimic the effects of exercise. This is called a pharmacological stress test.

What happens during a Stress Test?

The test itself will take around 1 hour, not including waiting time. This is what you should expect on the day of the test:

1.   The technician will place electrodes on your chest, legs, and arms.

2.   He/she will then attach wires to the electrodes and to the machine to record your heart’s electrical activity.

3.   A blood pressure cuff will be attached to your arm.

4.   Before proceeding with the exercise, the technician will measure your heart rate and blood pressure at rest. You may also be asked to breathe into a tube to check for your breathing throughout the exercise.

6.   You will be asked to walk/run on a treadmill or ride a stationary bike. The exercise intensity will be progressively increased at regular intervals.

7.   The test continues until you reach the target heart rate or until you experience difficulty breathing, dizziness or fatigue.

9.   Following the exercise, you will be asked to stand still and lie down for 5 minutes so that your doctor can continue to monitor you as your heart rate decreases back to normal.

10.  Once that is done, the electrodes will be removed and you can go back to normal activities unless your doctor says otherwise.

If you feel uncomfortable at any time during the test, please inform your cardiologist immediately.

You may be given your results right after the test or during a separate consultation date, depending on your condition and the clinic’s scheduling. Depending on the results, your cardiologist may schedule other tests such as the nuclear stress test or imaging tests such as an MRI or coronary angiogram. If you continue to experience symptoms following the test, your cardiologist may also admit you for further observation. This is on a case-by-case basis so be sure to discuss it with your doctor.

How to prepare for a Stress Test?

Your cardiologist will inform you of how to best prepare for an exercise stress test. Some of these to take note of:

• Avoid all caffeine-containing products (coffee, tea, sodas, chocolate, etc.) for at least 24 hours before the test. This includes decaf coffee as it may still contain small traces of caffeine.

• Do not eat or drink anything other than water for 4 hours before the test.

• Do not smoke or use any other forms of tobacco on the day of the test.

• Do not apply lotion, oil, or powder around the chest area.

• Small patches of hair may have to be shaved to ensure that the electrodes can stick closely to the skin.
• If you have diabetes, consult your doctor to see if you need to adjust your insulin dosage before the test.

• Avoid over-the-counter medications that contain caffeine for 24 hours before the test. You should tell your doctor all the medications you are currently taking to check if you need to stop taking them before the stress test.

• You may also have to stop taking certain heart and hypertension medications. Do consult your doctor before discontinuing any medications.

• Come in comfortable clothing and sports shoes as you will have to exercise during this test. Do not use any accessories as you will have to remove all of them before proceeding with the test.

Benefits vs. Risks of a Stress Test

The test itself is non-invasive and generally very safe and low-risk. This is why it’s very important for your cardiologist to have a detailed understanding of your symptoms, medical history and family’s medical history to adequately discern whether a stress test would be suitable.

If left untreated, the condition can be life-threatening so the benefits of identifying and quickly diagnosing your condition may outweigh the risks. Unless you have an underlying condition, the risks are minimal and the amount of data it can provide is crucial for your diagnosis and treatment.

Summary

A type of ECG, the exercise stress test is a non-invasive, safe, and highly available test to evaluate your heart’s response to increasing levels of activity and blood flow. It is useful in diagnosing coronary artery diseases and other blood flow-related heart conditions.

While there are some risks involved, its use in diagnosis and treatment planning makes it such a crucial tool. If you experience any heart-related symptoms such as chest pains, palpitations, shortness of breath, constant fatigue, fainting spells, etc. it is best to consult your doctor as soon as possible. A stress test, in combination with other diagnostic tests, might just save your life. It cannot be stressed enough: early diagnosis is the key to successful treatment.