Stress Dobutamine echo

What is an Echocardiogram?

An echocardiogram is a noninvasive radiological investigation that uses high-frequency ultrasound waves to assess the heart’s structure and function. These waves either pass through or bounce back after hitting on the heart, and the reflected signals are used to create images on a computer screen. We can then assess the structural defects, functional abnormalities, and the heart’s blood flow to identify diseases.

What is a Stress Echo?

Stress echo means doing this imaging while the heart is under stress, in other words, when the heart’s workload is increased [1]. This helps us uncover diseases that are not apparent whilst the heart is at rest or under minimum exertion. Stress dobutamine echo (SDE) can assess the degree of coronary artery disease, valvular heart disease, assess cardiac function before surgery, and know the limits of safe exercise after a heart attack. For this purpose, we can use either direct physical exercise or certain drugs to stress the heart.

Why use Dobutamine?

Dobutamine is one such drug that, when injected into a vein, will increase the increasing heart rate and blood pressure, in essence, the workload of the heart. As this does not require you to engage in any physical activity SDE becomes very useful in people who cannot and are not in a condition to perform .

Who Needs an SDE?

• Patients suffering from

1. 1. limb amputation
   2. bronchial asthma
   3. arthritis
   4. poor exercise capacity
   5. some conduction blocks in the heart
   6. with pacemakers

• An SDE can include different types of echocardiograms like,

1. 1. M mode echo – measures the size of the heart chambers and thickness of the walls.
   2. Doppler echo – measures the amount of blood pumped out of the chambers of the heart.
   3. Color Doppler – assess the direction of blood flow.
   4. 3D echo – capture the 3D structure of the heart.
   5. 2D echo – assess the structure and real-time motion of the heart.

How to prepare for an SDE

Patients have to stay fasting for 4 hours and should avoid smoking and caffeinated drinks for 24 hours. Also, some medications like beta-blockers, isosorbide mononitrate, nitroglycerin, and other over-the-counter medication should be stopped under medical advice. Therefore, you should review your medications as well as current health issues with your doctor before the test.

What happens during SDE

Each test takes about 15 minutes . Patients are advised to remove jewelry. Patients are asked to empty the bladder before the test. Then an IV line will be connected, and dobutamine infusion will be given while monitoring vital signs like heart rate, blood pressure, rate of breathing, and oxygen saturation. ECG tracing will be done simultaneously, and the reading and echocardiogram will be compared with each other. The rate of dobutamine infusion will be increased stepwise until the maximum dose of dobutamine or the target heart rate is achieved. With each increment of the infusion, blood pressure reading, ECG tracing, and echocardiogram will be recorded. Once the infusion is stopped, vitals will further be monitored for another 10-15 minutes until the baseline values are reached. Patients are advised to tell the health care team if any chest pain, sweating, or breathing difficulty develops, which suggests complications of the procedure.

Complications of SDE

Possible risks of the procedure include developing a heart attack due to increased activity of the heart when the overworked muscle is unable to tolerate its blood supply . Features that help to recognize heart attacks are chest pain, palpitations, dizziness, nausea, fatigue, and sweating. Some can develop severely high blood pressure.

After SDE, patients can go back to their regular diet and lifestyle unless abnormal findings are detected from the test, if so, they will have to be initiated on drug therapy and lifestyle modifications..

References

1. Dobutamine Stress Echocardiogram. Hopkinsmedicine.org. https://www.hopkinsmedicine.org/health/treatment-tests-and-therapies/dobutamine-stress-echocardiogram. Published 2021.
2. Dobutamine Stress Echocardiogram. Cleveland Clinic. https://my.clevelandclinic.org/health/diagnostics/16935-dobutamine-stress-echocardiogram. Published 2021.
3. Dobutamine (stress) echocardiogram | Royal Brompton & Harefield hospitals. Rbht.nhs.uk. https://www.rbht.nhs.uk/our-services/dobutamine-stress-echocardiogram. Published 2021.