What interferes with ST segment changes on exercise stress test?

For example, ST-Segment changes may be affected by abnormal resting ECG (bundle branch block, left ventricular hypertrophy, digitalis drug) so resting ECG responses should be examined carefully. Healthy subjects may have J-point depression and an enhanced T-wave at high intensities exercise and also recovery.

What happens to ST segment during exercise?

Normal trace during exercise The J point (the point of inflection at the junction of the S wave and ST segment) becomes depressed during exercise, with maximum depression at peak exercise. The normal ST segment during exercise therefore slopes sharply upwards.

What is St in stress test?

Objective: The electrocardiogram (ECG) obtained during stress testing often shows a typical pattern of primary ST depression. A similar pattern can occur in unstable angina. Current textbooks consider ST depression as a direct result of partial occlusion of a coronary artery.

Can stress cause ST elevation?

Several other case reports also found rare cases of ST elevations in non-Q wave leads during exercise stress testing that accurately predicted the presence of coronary stenoses (9–11).

What does ST segment depression indicate?

ST depression occurs when the J point is displaced below baseline. Just like ST elevation, not all ST depression represents myocardial ischemia or an emergent condition. There are multiple conditions associated with ST depression. Some of these include hypokalemia, cardiac ischemia, and medications such as digitalis.

What does ST depression mean during a stress test?

In a cardiac stress test, an ST depression of at least 1 mm after adenosine administration indicates a reversible ischaemia, while an exercise stress test requires an ST depression of at least 2 mm to significantly indicate reversible ischaemia.

What is the normal ST segment?

The ST segment is the interval between the end of the QRS complex (J point, or ST junction) and the beginning of the T wave. In the limb leads, the ST segment is isoelectric in about 75 percent of normal adults. ST segment elevation or depression up to 0.1 mV generally is considered within normal limits.

Is ST depression normal during stress test?

Interpretation of the treadmill ECG stress test A treadmill ECG stress test is considered abnormal when there is a horizontal or down-sloping ST-segment depression ≥ 1 mm at 60–80 ms after the J point. (9) Exercise ECGs with up-sloping ST-segment depressions are typically reported as an ‘equivocal’ test.

What are the causes of ST elevation?

Causes of ST Segment Elevation

• Acute myocardial infarction.
• Coronary vasospasm (Printzmetal’s angina)
• Pericarditis.
• Benign early repolarization.
• Left bundle branch block.
• Left ventricular hypertrophy.
• Ventricular aneurysm.
• Brugada syndrome.

What does ST elevation mean in ECG?

ST elevation refers to a finding on an electrocardiogram wherein the trace in the ST segment is abnormally high above the baseline.

Can ST segment depression be normal?

ST segment depression of 1 mm or more, lasting 0.08 second or more, is generally considered a positive (abnormal) response. False-negative (normal) results can occur, however, in patients with ischemic heart disease and false-positive results can occur in normal people.

Why does ST segment depression occur?

ST segment depression occurs because when the ventricle is at rest and therefore repolarized, the depolarized ischemic subendocardium generates electrical currents that are recorded by an overlying electrode.

How does the ST segment change with stress?

ECG at peak stress showed sinus tachycardia at a rate of 146 bpm. There were new horizontal and up-sloping ST-segment depressions in leads II, III, aVF and V4–6, which were suggestive of myocardial ischaemia. In addition, there was an isolated 1-mm ST-segment elevation in lead aVL.

When does a treadmill stress test show abnormal ST segments?

ST-segment changes indicative of obstructive CAD. A treadmill ECG stress test is considered abnormal when there is a horizontal or down-sloping ST-segment depression ≥ 1 mm at 60–80 ms after the J point.(9) Exercise ECGs with up-sloping ST-segment depressions are typically reported as an ‘equivocal’ test.

What does stsegment mean on a stress test?

Abstract The treadmill electrocardiogram (ECG) stress test is widely used to screen for obstructive coronary artery disease (CAD). The presence of STsegment changes, either depression or elevation, on the ECG during the treadmill test often suggests presence of CAD and warrants further management.

When to use exercise stress test for ST segment depression?

Both clinical and exercise data of patients are entered into an electronic database. Among patients who underwent an exercise stress test from 1992 to 1999, we selected those who developed significant ST segment depression (see below) during a symptom limited exercise test and who underwent coronary angiography within six months of the test.