Echocardiography

Echocardiography uses high-frequency (ultrasound) waves bounced off internal structures to produce a moving image. It uses no x-rays. Echocardiography is one of the most widely used procedures for diagnosing heart disorders because it is noninvasive, harmless, relatively inexpensive, and widely available and because it provides excellent images.

Echocardiography can be used to detect abnormalities in heart wall motion and to measure the volume of blood being pumped from the heart with each beat. This procedure can also detect abnormalities in the heart’s structure, such as defective heart valves, birth defects, and enlargement of the heart’s walls or chambers, as occurs in people with heart failure or cardiomyopathy.

Echocardiography can also be used to detect pericardial effusion, in which fluid accumulates between the two layers of the sac that envelops the heart pericardium, and constrictive pericarditis, in which scar tissue forms throughout the pericardium.

The main types of Echo are M-mode, two-dimensional, Doppler, and color Doppler.  Two dimensional Echo which is the most  widely used technique, produces realistic two dimensional images in computer-generated  "slices." Stacking the slices together can recreate a three dimensional structure. Doppler Echo shows the direction and velocity of blood flow and thus can detect turbulent flow due to narrowing or blockage of blood vessels. Color Doppler echocardiography shows the different rates of blood flow in different colors. Doppler and color Doppler echocardiography are commonly used to show the direction and rate of blood  flow in the chambers and blood vessels of the  Heart and enable doctors to evaluate the  structure and function of these structures. For example, doctors can determine if the heart valves open and close properly, if and how much they leak when closed, and if blood flows normally. Abnormal connections between an artery and a vein or between heart chambers can also be detected.

The ultrasound waves are emitted by a handheld recording probe transducer. For echocardiography, the examiner places gel on the chest over the heart and moves the probe over that area. The probe is connected to a monitor that displays an image. The image is recorded on a videocassette, a computer disk, or paper. By varying the placement and angle of the probe, doctors can view the heart and nearby major blood vessels from various angles and thus get an accurate picture of heart structure and function.

Echocardiography is painless and takes 20 to 30 minutes. If doctors need to obtain greater clarity or to analyze the aorta or structures at the back of the heart {particularly the left atrium or left ventricle], transesophageal echocardiography can be used. For this procedure, a probe is passed down the person’s throat into the esophagus. The probe records signals from just behind the heart. Transesophageal echocardiography is also used when regular echocardiography is difficult to perform because of obesity, lung disorders, or other technical problems.

Exercise Echocardiogram

The exercise echocardiogram is another type of stress test. This test combines exercise and echocardiogram pictures to show the contraction of the heart. After a resting test is performed, the patient is asked to walk on a treadmill. The results of this test are compared with the resting echocardiogram. If segments of the heart are no longer contracting well, it can be concluded that these areas are not getting enough oxygenated blood. There may be a coronary artery blockage. If one is unable to exercise for whatever reason, drugs can be used to induce heart stress. Otherwise, the testing procedure remains the same. 

During the echo

You will remove any clothing above the waist and put on a hospital gown. You will be asked to lie on your left side. A nurse or technician will put a gel on your chest. The gel may feel cold. A small plastic device, called a transducer, will be placed on your chest, over your heart. The transducer sends and receives high frequency sound waves. As the sound waves bounce off different parts of your heart, they are picked up by the transducer and sent to a monitor. The monitor shows a picture of your beating heart. You may hear a “whooshing” sound, timed with your heart beat. This is the sound of blood moving through your heart.