Stress Echocardiography
Stress echocardiography combines an echocardiogram with a stress test — either exercise on a treadmill or bike, or a pharmacological stress with the drug dobutamine. Images of the heart are taken at rest and at peak stress, and compared. Areas of the heart that don’t behave normally under stress give important clues to coronary disease, valve disease and exercise tolerance.
What is stress echocardiography used for?
- Coronary artery disease — to look for areas of the heart muscle that don’t contract properly when oxygen demand increases. This points to a narrowed coronary artery supplying that part of the heart.
- Severe asymptomatic aortic stenosis — to provoke exertional changes in symptoms or pressure gradient that can guide the timing of intervention.
- Aortic regurgitation and mitral regurgitation — to clarify the haemodynamic significance and exercise tolerance.
- Mitral stenosis — to identify exercise-induced rises in pulmonary pressure.
- Low-flow low-gradient aortic stenosis — to confirm whether truly severe AS is present in patients with reduced left ventricular function.
- Unexplained breathlessness — to evaluate the cause when resting tests are inconclusive.
What can I expect?
You will be asked to wear loose, comfortable clothing and bring trainers if you are having an exercise stress echo. Eat lightly beforehand. The test usually lasts about 45 to 60 minutes.
For an exercise stress echo, you walk on a treadmill or pedal an exercise bike with the workload gradually increased. Echocardiographic images are taken at rest, immediately after stopping, and during recovery.
For a dobutamine stress echo (used when patients cannot exercise, or for specific clinical questions), the drug is given through a small cannula in the arm and gradually increased to raise the heart rate. Images are taken at each stage.
Throughout the test you are continuously monitored with an ECG and blood pressure cuff, and the test is supervised by a cardiologist. You can drive yourself home afterwards (unless you have had sedation).
Are there any risks?
Stress echocardiography is very safe. The risks of exercise stress are essentially the risks of vigorous exercise itself. Dobutamine stress carries a small risk of provoking an arrhythmia, which is why it is performed under cardiology supervision with continuous monitoring.