Following the previous article about having heart attacks at a younger age where I explained that we are seeing more and more incidences of heart attacks in younger people, let’s further discuss this and bring some light onto the various cardiac screening and diagnostic tools; namely the exercise stress test.
So in this article, I’ll try and further explain the need for an Exercise Stress Test, how it’s done and how you should prepare for this.
In essence, this is a screening tool used to identify if there are any issues with heart circulation and if any are picked up, to allow a more qualitative assessment into the situation. We use this as a tool to assess the functional capacity of the heart.
We’d tend to recommend these things if you have had any incidences of chest pains, difficulty breathing, the short onset of dizziness/vertigo, reduced effort tolerance and similar symptoms. All of these may indicate a deeper heart circulatory issue that should be investigated.
Introduction
We know that a heart attack is brought on in conditions where the heart, for whatever reason, cannot pump enough blood through its vessels to maintain a good state of perfusion and circulation around the organ. With the lack of blood supply (ischemia), the heart cells will lose its nutrients (that are carried along in the blood) and therefore be drained of its power to contract. When a significant enough number of heart cells (myocytes) eventually die from this draught, the heart will be immediately paralysed.
When we say immediately, it’s worth noting that that entire process of cell death can happen within minutes.
When this happens, this is called a heart attack aka a myocardial infarction. Literally translated, myocardial infarction is a fancy term for when the heart cells lack perfusion which causes them to die.
Therefore when it comes to screening processes to find out the status of heart health, we always try and perform tests that allow us to concretely measure the efficiency of the heart muscle. This can be done without load or with the load. Meaning, we can either stress the heart via exercise or scan the heart parameters while you’re at rest.
Is the Exercise Stress Test the only way to know my heart health?
Well, not really. We can perform a number of tests can be done to achieve this effect. In this article, we’re going to focus more on EST (Exercise Stress Test) but you should also know that we can do ECG (electrocardiogram) or echocardiography of the heart to assist in this as well.
An ECG is basically where we attach electrodes capable of measuring the electrical currents (the heart doesn’t run on electricity – no worries) running through the heart and translating that into a series of graphs (or wave patterns, if you’d like) onto a paper for us to interpret.
This allows us to determine the rate and rhythm of your heart. Basically, a rate of between 60 to 100 beats per minute is fairly normal and there should be any abnormal beats (arrhythmia). Arrhythmias can be lethal at times. That’s not ideal to pick up during a routine screening test.
An echocardiography (ECHO) on the other hand is a more comprehensive screening tool where we use sound waves (like sonar or scanning for a baby in a pregnant woman) to visualise the heart, its chambers and valves and from there determine if it is contracting at a healthy enough rate to maintain the body’s daily functions.
Apart from running these sort of physical tests, we can also determine general health and to a certain extent, heart health from physical examinations and blood tests for cholesterol levels, sugar levels and for high blood pressure issues. All these tests done in tandem will give us a pretty good idea of your cardiac status.
What is Exercise Stress Testing (EST)?
Exercise Stress Testing (EST) is a cardiovascular stress test that uses treadmill exercise with electrocardiography (ECG) and blood pressure monitoring. Basically, we continuously monitor your heart rhythm and activity while we put it under load – this is where the exercise (running) comes in.
As your body works harder during the test, it requires more oxygen, so the heart must pump more blood. The test can show if the blood supply is reduced in the arteries that supply the heart.
This will let us know the overall contractility of the heart and the rate of perfusion of the heart under extreme stress. The better your heart vessels are at adapting to being worked out, the better the blood flow will be to the heart and therefore with no shortage of blood supply, there will be less risk of you developing a heart attack under normal circumstances.
How is Exercise Stress Testing (EST) done?
The test is usually done by a doctor or cardiac technician. Prior to the test, we’d ask you about your previous medical history, review your previous medication and perform a simple physical examination that includes blood pressure monitoring.
Once that is done, you’d be recommended to change into your exercise clothes and we’ll begin the test preparation proper.
First, we’ll hook you up to the equipment. This is where we’ll attach a myriad of wires connected to electrodes (similar to an ECG) to your chest and body. This entire wiring harness is connected to a computer that modulates the treadmill.
There’s also a printer in there somewhere to help with the report printing but that’s just some nice-to-know information.
Your personal data will then be put into the system and we’ll begin the test.
The treadmill will start at a slow walking pace (the warm-up) and gradually work its way up to jogging then running pace. Each of these steps is regulated in stages where each stage lasts three minutes.
We’ll end the test with a cool down phase and get you settled back into your routine daily rhythm.
Throughout the procedure, we will monitor your heart rate, breathing, blood pressure, electrocardiogram (ECG or EKG), and how tired you feel are monitored during the test.
If at any time during the test, you become uncomfortable, breathless, develop chest pains or feel unable to continue for whatever reason, all you have to do is inform the doctor and we’ll stop the test and examine the results.
Once the test is done, a report will be printed out and your physician will explain it to you.
Why is Exercise Stress Testing (EST) done?
Trust me, it’s really not so that we can have a chuckle while looking at you all dressed up like Dr Frankenstein’s creation.
As aforementioned, these tests are done in conjunction with other tests such as a proper physical examination, blood investigations and other tests to get a better understanding of the coronary (heart) health. The Exercise Stress Test is a simple but effective tool to:
Diagnose a coronary artery disease
- Identify a possible heart-related cause of symptoms such as chest pain, shortness of breath or lightheadedness.
- Determine a safe level of exercise per individual.
- Check the effectiveness of procedures done to improve coronary artery circulation in patients with coronary artery disease
- Predict risk of dangerous heart-related conditions such as a heart attack (risk stratification)
Can I get an Exercise Stress Testing (EST) done?
Basically yes. There are, however, a few situations where we’d advise against EST but suggest an alternative screening method.
These include people who are already having chest pains or having difficulty breathing. No need to stress an already stressed person, right?
Also, if you already have heart disease (such as diagnosed heart failure), we might take more precautions into getting this test done. If we already know the stage of heart failure, then this test will offer no further benefit. If you have recently done some sort of stenting procedure for a heart attack, you should inform the doctor as well. It’s not likely that we will continue on with this.
If it has been about a year since the stenting was done, we would have better reasoning to proceed with the EST.
Of course, if you already have an astronomically high blood pressure reading prior to starting the test, we’d probably skip the test as well.
Lastly, if you have just suffered a stroke or physically impaired in any way, we certainly would not subject you to such an exertive activity.
So there you have it. Hopefully reading this article provides you with a little insight into the mind of a physician such as myself into why we choose to do the test in some people and not in other people. Perhaps, you’d have also understood a little more about heart health and why it’s such a complicated and sometimes a necessary expense to get to know your heart better.
Take care.
