A stress echocardiogram is a diagnostic imaging procedure that evaluates heart function under increased demand. It combines an ultrasound of the heart with controlled physical or pharmacological stress. This test reveals issues not apparent at rest, providing insights into the heart’s performance when working harder.
What a Stress Echocardiogram Is
A stress echocardiogram integrates two components: an echocardiogram and a stress test. An echocardiogram uses sound waves to create moving images of the heart, showing its chambers, valves, and overall pumping action. The “stress” aspect involves safely increasing the heart’s workload, either through exercise or with medication.
This combined approach assesses how the heart muscle and its blood vessels respond to increased demand. Under stress, areas of the heart not receiving enough blood flow, often due to narrowed arteries, can show abnormalities not visible at rest. This test helps identify issues like reduced blood supply to the heart muscle.
How the Test is Conducted
The stress echocardiogram procedure involves several steps, beginning with preparation and leading into the stress phase. Patients are advised to avoid eating or drinking for a few hours before the test and to wear comfortable clothing and shoes. They may also be instructed to avoid caffeine for 24 hours prior, and sometimes certain medications. The entire test usually takes about 20 to 60 minutes.
Initially, a resting echocardiogram is performed. Electrodes are placed on the chest to monitor the heart’s electrical activity (ECG), and a blood pressure cuff measures blood pressure. A sonographer uses a transducer to capture ultrasound images of the heart while the patient lies still. These images establish a baseline of the heart’s function at rest.
Following the resting images, the stress phase begins. For an exercise stress echocardiogram, the patient walks on a treadmill or pedals a stationary bicycle. The speed and incline or resistance are gradually increased to elevate the heart rate to a target level. During this exercise, heart rate, blood pressure, and ECG are continuously monitored. Immediately after peak exertion, the patient returns to the imaging table for a second set of echocardiogram images, captured while the heart is still working hard.
If a patient is unable to exercise due to physical limitations, a pharmacological stress echocardiogram is performed. Medications, most commonly dobutamine, are administered intravenously to simulate exercise effects by increasing heart rate and pumping strength. Throughout the medication infusion, heart activity is monitored, and echocardiogram images are taken at various intervals as the heart rate increases, similar to the exercise protocol.
Reasons for the Test
Medical professionals recommend a stress echocardiogram primarily to evaluate the heart’s response to increased demand. It is frequently used to investigate symptoms suggesting coronary artery disease, a condition where the heart’s blood vessels become narrowed. These symptoms include chest pain (angina) or shortness of breath, especially when worsening with activity.
Beyond diagnosing blockages, the test assesses the impact of known heart conditions. It can determine how well the heart’s pumping chambers and valves function under stress. It is also used to evaluate heart muscle damage following a heart attack, guide treatment plans for existing heart conditions, or aid in risk assessment before non-cardiac surgeries.
Understanding Your Results
After a stress echocardiogram, a cardiologist analyzes the collected images and data. A “normal” or “negative” result indicates the heart muscle showed no significant issues or reduced blood flow under stress. This means all parts of the heart responded by pumping harder as expected, with no new wall motion abnormalities detected. Such a result suggests coronary arteries provide sufficient blood flow even when the heart is working intensely.
Conversely, an “abnormal” or “positive” result suggests certain heart muscle areas did not function as expected during stress. This can manifest as reduced blood flow to a specific region or as new or worsening wall motion abnormalities. These findings indicate narrowed or blocked coronary arteries, which limit blood supply to the heart muscle when needed most. An abnormal result can also point to issues with heart valve function or other structural problems.
Results are always interpreted in the context of a patient’s overall health, medical history, and symptoms. Based on these findings, medical professionals determine the next appropriate steps, which may include further diagnostic tests, medication adjustments, or lifestyle change recommendations.