Echocardiography
Echocardiography, or cardiovascular ultrasound, is the most widely performed cardiac imaging test to assess the heart’s structure and function. This low-cost, portable technology doesn’t expose patients to radiation and lets us capture both still images and moving images.
During a transthoracic echocardiogram, the patient lies down while a sonographer places a handheld transducer in various locations on the patient’s chest. The transducer emits high-pitched sound waves directed at the heart and surrounding structures and captures the waves as they bounce back to form images of the heart. Sound waves cannot travel through air, so we apply a clear, gel-like substance to the chest and the transducer to enhance the soundwaves.
In some cases, a transthoracic echocardiogram can’t capture the images we need. A transesophageal echocardiogram uses a small ultrasound probe inserted through the esophagus. Patients don’t experience discomfort during this 10- to 15-minute test. Transesophageal echocardiography is ideal for obtaining images in patients with prosthetic heart valves, thrombus (blood clot) within the heart, and some forms of congenital heart disease.
Stress echocardiography
Stress echocardiography is a modification of a standard exercise treadmill test used to diagnose coronary artery disease. A resting echocardiogram will be done first. While you lie on your left side with your left arm out, a small device called a transducer is held against your chest. A special gel is used to help the ultrasound waves get to your heart.
Most people will walk on a treadmill (or pedal on an exercise bicycle). Slowly, usually every 3 minutes, you will be asked to walk (or pedal) faster and on an incline. It is like being asked to walk fast or jog up a hill.
Usually, you will need to walk or pedal for around 5 to 10 minutes. Your doctor will ask you to stop:
- When your heart is beating at the target rate
- When you are too tired to continue
- If you are having chest pain or a change in your blood pressure that worries your doctor
If you are not able to exercise, you will get a medication such as dobutamine through a vein (intravenous line). This medicine will make your heart beat faster and harder, similar to when you exercise.
Your blood pressure and heart rhythm (ECG) will be monitored throughout the procedure.
More echocardiogram images will be taken while your heart rate is increasing or when it reaches its peak. The images will show whether any parts of the heart muscle do not work as well as your heart rate increases. This is a sign that part of the heart may not be getting enough blood or oxygen because of narrowed or blocked arteries.