Stress Echocardiography
Stress echocardiography is a combination of treadmill testing and
echocardiography utilized to detect and manage coronary atherosclerotic heart
disease. The principle behind the procedure is relatively straightforward: heart
muscle supplied by a significantly blocked artery may contract normally or
almost normally under sedentary conditions but when placed under a workload, the
heart muscle supplied by that same blocked artery may fail to contract properly.
The abnormal contraction may be detected by ultrasound imaging of the heart. In
other words, the heart has a clogged fuel line and its engine starts knocking!
Increase contractility is a normal response to exercise or with stimulation with
a drug known as Dobutamine. Dobutamine also increases heart rate and
contractility similarly to exercise.
A stress echocardiography study is performed by obtaining four standardized
views of the patient's heart at rest. The patient is prepared for a treadmill
study (or a pharmacological study utilizing Dobutamine stimulation). The patient
walks on a treadmill (or receives Dobutamine in increasing increments) to
increase the heart rate to a predetermined target level based upon the patient's
age or the development of symptoms. The patient then undergoes a second set up
echocardiographic imaging post-exercise (or post-Dobutamine stimulation) and the
pre-exercise images are compared to the post-exercise images looking for changes
in wall motion. The expected response is a hyperdynamic contractile state
post-exercise involving all cardiac segments. The failure of one or more
segments to increase contractility following exercise (or Dobutamine
stimulation) signifies abnormal heart muscle in that segment either due to poor
blood flow (known as ischemia) or some type of muscle dysfunction (possibly due
to a viral inflammation of the heart muscle known as a myocarditis or a primary
weakness of the heart muscle known as a cardiomyopathy).
By analyzing the images and understanding which segment(s) failed to increase
its contractility as well as armed with a knowledge of coronary artery anatomy,
a patient can be advised whether or not there is the potential for a significant
blockage to be present and further recommendations regarding management and
diagnosis can be made.
No special preparation is required prior to the performance of this study. The
patient will be informed of the results immediately following the procedure and
a written report will be forwarded to the referring physician generally by the
next business day.
See our Patient Brochure Page.
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