Dr Reza Moazzeni | Cardiologist Sydney (Westmead)
What is stress echocardiogram or stress echo?
A stress echocardiogram is a diagnostic procedure that blends a stress test with an echocardiogram to enhance the accuracy of heart function evaluation. It involves treadmill exercise, followed by imaging using an ultrasound device, providing vital insights into your heart’s performance under stress.
Table of Contents
Stress echocardiogram is a non-invasive diagnostic procedure that combines a stress test with echocardiogram to evaluate the heart’s function under physical stress. Its purpose is to identify potential issues, such as reduced blood flow to the heart muscle (ischemia), which may be caused by narrowed or blocked coronary arteries. The test helps healthcare providers make informed decisions about a patient’s heart health, including the need for further testing or treatment and allows them to monitor the effectiveness of existing treatment plans.
Indications for stress echo (Why you might require stress echocardiogram)
- Diagnosing ischemia: A primary purpose of the test is to identify and evaluate limited blood flow to the heart muscle, usually due to narrowed coronary arteries. The test can detect ischemia sooner by putting the heart under stress through exercise and raising the heart rate. In the early stages of ischemia, chest pain occurs only during exercise and physical activity, not while resting.
- Direct assessment of patients’ complaints and other diagnoses: A stress test provides a valuable chance to observe patients’ concerns directly and evaluate their exercise capabilities. In many instances, the test can identify and distinguish lung-related conditions as the primary cause behind their complaints. Experiencing the issue first-hand is much more insightful than relying on descriptions alone.
- Assessing other heart conditions: Stress echo can evaluate the severity of some heart valve issues like Aortic Valve Stenosis (AS) or the ability of the heart to pump harder in cases of heart failure.
- Evaluating exercise tolerance: The test can help determine a patient’s ability to tolerate physical exertion, especially for those with known heart conditions or prior heart surgeries. It can also be used to establish a safe level of exercise for patients starting cardiac rehabilitation programs.
- Detecting abnormal heart rhythm: Stress echocardiograms can reveal exercise-induced arrhythmias or irregular heartbeats that may not be apparent at rest, which could indicate underlying heart issues.
- Assessing the effectiveness of treatments: The test can be used to monitor the progress of patients undergoing treatment for heart conditions, such as medications or interventions like angioplasty, and determine the need for further procedures or adjustments in their treatment plan.
- Preoperative assessment: In some cases, a stress echocardiogram may be performed before non-cardiac surgeries to evaluate the patient’s cardiac risk and ensure their heart can tolerate the stress of surgery.
How to prepare for stress echocardiogram
To ensure a smooth stress echocardiogram experience, follow these preparation tips:
- Clothing: Wear comfortable, loose-fitting clothes, such as athletic wear, that allow for easy movement during the test. Opt for supportive, non-slip shoes like sneakers or running shoes to ensure safety on the treadmill.
- Fasting: Generally, it’s recommended to avoid eating or drinking anything (except water) for at least 3-4 hours before the test. This helps prevent nausea or discomfort during the exercise portion of the procedure.
- Medications: Discuss any medications you are taking with your healthcare provider in advance.
- Caffeine and nicotine: Avoid consuming caffeine (coffee, tea, energy drinks, or chocolate) and nicotine (cigarettes, e-cigarettes, or nicotine patches) for at least 24 hours prior to the test, as these substances can interfere with the results.
- Alcohol: Refrain from drinking alcohol for at least 24 hours before the test, as it can affect your heart’s response to exercise.
- Personal items: Remove any jewellery, watches, or electronic devices before the test, as they may interfere with the echocardiogram equipment.
The Stress Echocardiogram Procedure: Step-by-Step
The stress echocardiogram procedure consists of several stages, including treadmill exercise, heart rate monitoring, and ultrasound imaging. Here’s a step-by-step breakdown of the process:
- Baseline echocardiogram: While you are at rest, the sonographer will perform an initial echocardiogram to obtain baseline images of your heart. This involves applying a gel on your chest and using an ultrasound probe to capture images of your heart’s chambers, valves, and overall function.
- Treadmill exercise: Next, you will begin the exercise portion of the test, which typically involves walking or running on a treadmill. The treadmill’s speed and incline will gradually increase to raise your heart rate and simulate physical exertion. Your healthcare provider will closely monitor your heart rate, blood pressure, and any symptoms you may experience during this stage.
- Post-exercise echocardiogram: As soon as you complete the treadmill exercise, the sonographer will quickly perform another echocardiogram to capture images of your heart while it’s still working hard. This allows them to compare the post-exercise images with the baseline images to assess how your heart responds to stress.
- Recovery monitoring: After the post-exercise echocardiogram, you will be given some time to rest and recover. We continue to monitor your heart rate, blood pressure, and symptoms until they return to normal levels.
- Result analysis: Once the test is complete, Cardiologist will analyze the echocardiogram images and other data collected during the test. He will then discuss the test results with you and, if necessary, recommend further testing or treatment options based on the findings.
Typical images of a stress echocardiogram
Normal Stress Echocardiogram: In the following video, we can see a normal stress echocardiogram. The two images on the left show the heart at rest, with a heart rate of about 70 beats per minute. The two images on the right show the same images after exercise with a heart rate of about 120 beats per minute. We can see an excellent contraction of the heart muscle post-exercise with no lagging in any section.
Abnormal Stress Echocardiogram: In this video, again on the left side, we can see the heart at rest and on the right, the heart after exercise. However, in this instance, there is an area of the heart that doesn’t contract properly after exercise, where the arrows are pointing. This is due to a severe blockage in one of the main arteries of the heart, the LAD, which was confirmed with a coronary angiogram.
Understanding the Results: What to Expect
The possible outcomes of a stress echocardiogram can vary, and they may impact your treatment plan differently depending on the findings. At Heartcare Sydney, the Cardiologist will discuss the results with the patient immediately after the test. Here are some possible results and their implications:
- Normal response: The test outcome is considered normal if your heart responds appropriately to exercise, with no signs of reduced blood flow or other abnormalities. In this case, you may not require further action or changes to your current treatment plan.
- Abnormal response: If the test reveals issues such as reduced blood flow to the heart muscle (ischemia), abnormal heart rhythms, or problems with the heart valves or chambers, the outcome is considered abnormal. Depending on the severity and specific findings, you may require additional tests or interventions, such as medications, lifestyle changes, angioplasty, or surgery.
- Inconclusive results: In some cases, the test results may be inconclusive or difficult to interpret. This could be due to factors such as poor image quality, an inadequate increase in heart rate, or inconclusive stress-induced changes. If this occurs, you may require alternative diagnostic tests, such as a nuclear stress test or a coronary CT angiogram, to obtain more definitive information.
Potential Risks and Complications of Stress Echocardiograms
While a stress echocardiogram is generally considered safe and non-invasive, there are some potential risks and complications associated with the test:
- Abnormal heart rhythms: During the exercise portion of the test, some individuals may experience abnormal heart rhythms (arrhythmias), such as an excessively fast or irregular heartbeat. These arrhythmias are usually short-lived and resolve spontaneously once the exercise is stopped. However, they may require medical attention in rare cases.
- Low blood pressure or dizziness: Exercise-induced changes in blood pressure might cause some patients to feel lightheaded or dizzy during the test. These symptoms typically resolve once the exercise is stopped.
- Chest pain or shortness of breath: Some patients may experience chest pain (angina) or shortness of breath during the test, especially if there is reduced blood flow to the heart muscle. We will stop the test and provide appropriate medical care if these symptoms occur.
- Heart attack: Though extremely rare, a heart attack can occur during a stress echocardiogram, particularly in individuals with significant underlying coronary artery disease. If a patient experiences severe chest pain or other signs of a heart attack, the test will be stopped immediately, and emergency medical care will be provided.
It’s important to note that the risks associated with stress echocardiograms are relatively low, and the test is generally considered safe. We will carefully monitor you throughout the test to ensure your safety and promptly address potential concerns.
What are the alternative tests to Stress Echocardiogram?
There are alternative diagnostic methods available for patients who cannot undergo the standard treadmill stress echocardiogram due to mobility issues, health limitations, or other concerns. One such option is the pharmacological stress test, which utilizes medication to simulate the effects of exercise on the heart:
Pharmacological nuclear stress testing
Instead of exercising on a treadmill, patients receive a medication—typically adenosine, dipyridamole, or regadenoson—that dilates their coronary arteries and increases blood flow to the heart, mimicking the effects of physical exertion. This method is particularly suitable for those with physical limitations, such as arthritis, disabilities, or severe lung diseases, that prevent them from exercising adequately. During a pharmacological stress test, the patient’s heart rate, blood pressure, and ECG are closely monitored, similar to a standard treadmill test. A nuclear imaging technique, such as SPECT (single-photon emission computed tomography) or PET (positron emission tomography), is performed at rest and during the peak effect of the medication to assess the heart’s response to stress.
Dobutamine stress echocardiography
Another alternative for patients who cannot exercise is the dobutamine stress echocardiography. Dobutamine – a medication that increases heart rate and contractility – is administered intravenously to stimulate the heart’s workload. Echocardiograms are taken at rest and during the peak effect of dobutamine to evaluate the heart’s function and blood flow.
These alternative methods allow us to assess a patient’s heart function and blood flow in response to stress, even when traditional exercise-based stress testing is not feasible. It’s essential to discuss your specific situation to determine the most appropriate diagnostic method for your needs.
Frequently Asked Questions about Stress Echocardiograms
Here are some common questions and concerns related to stress echocardiograms:
- Test duration: The entire stress echocardiogram process, including preparation, exercise, imaging, and recovery, typically takes between 45 minutes to an hour. The actual exercise portion of the test is usually short, lasting around 6-12 minutes, depending on your fitness level and the test protocol.
- Need for follow-up tests: The need for follow-up tests depends on the results of your stress echocardiogram. We may not recommend additional testing if the test results are normal and no significant concerns are identified. However, if the results are abnormal, inconclusive, or reveal issues that require further evaluation, we may recommend follow-up tests, such as a coronary angiogram, nuclear stress test, or coronary CT angiogram, to obtain more detailed information about your heart health.
- Test discomfort: Some patients may be concerned about the discomfort during the test. While the exercise portion can be physically demanding, we will closely monitor you and adjust the test protocol based on your individual needs and capabilities. If you experience any severe discomfort, chest pain, or other concerning symptoms, inform us immediately so we can stop the test and provide appropriate care.
- Radiation exposure: Unlike some other cardiac diagnostic tests, such as nuclear stress tests or CT scans, stress echocardiograms do not involve ionizing radiation. The test utilizes ultrasound technology, which is considered safe and non-invasive.
Stress echocardiograms play a crucial role in cardiac care by providing valuable insights into your heart’s function, response to stress, and blood flow. This non-invasive and safe diagnostic test can help identify and monitor numerous conditions such as ischemia, heart valve abnormalities, and exercise-induced arrhythmias. By detecting potential issues early, a stress echocardiogram can guide appropriate treatment strategies, including lifestyle changes, medications, or surgical interventions, ultimately improving heart health and overall well-being.
If you have concerns about your heart health or have been experiencing symptoms such as chest pain, shortness of breath, or unexplained fatigue, it’s essential to consult with your healthcare provider. Remember that proactive measures and open communication with your healthcare provider are vital to maintaining a healthy heart and enjoying a better quality of life.