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Cardiac stress test (or
Cardiac diagnostic test) is a test used in medicine and cardiology
to measure the heart's ability to respond to external stress in a
controlled clinical environment.
The stress response is induced by exercise or drug stimulation.
Cardiac stress tests compare the coronary circulation while the
patient is at rest with the same patient's circulation observed
during maximum physical exertion, showing any abnormal blood flow to
the heart's muscle tissue (the myocardium).
The results can be
interpreted as a reflection on the general physical condition of the
test patient. This test can be used to diagnose ischemic heart
disease, and for patient prognosis after a heart attack (myocardial
infarction).
The cardiac stress test is done with heart stimulation, either by
exercise on a treadmill, pedalling a stationary exercise bicycle
ergometer or with intravenous pharmacological stimulation, with the
patient connected to an electrocardiogram (or ECG). People who
cannot use their legs may exercise with a bicycle-like crank that
they turn with their arms.
The level of mechanical stress is progressively increased by
adjusting the difficulty (steepness of the slope) and speed. The
test administrator or attending physician examines the symptoms and
blood pressure response. With use of ECG, the test is most commonly
called a cardiac stress test, but is known by other names, such as
exercise testing, stress testing treadmills, exercise tolerance
test, stress test or stress test ECG.
A stress test may be accompanied by echocardiography. The
echocardiography is performed both before and after the exercise so
that structural differences can be compared.
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