Figure 1: ECG Strip
ST depression and ST elevation are forms of ST segment abnormalities caused by myocardial ischaemia or infarction. The ST segment is the section of the ECG between the end of the S-wave and the beginning of the T-wave. ST depression occurs when the ST segment is depressed in comparison to the PR segment. Specifically, the ST segment represents "the interval between ventricular depolarization and repolarization.''
- Clinical circumstances surrounding ECG changes are crucial in diagnosing the specificity of ST segment abnormalities.
- Various factors, in addition to myocardial disease, can affect ST segment configuration:
- Electrolyte abnormalities of potassium, magnesium, and calcium
- Neurogenic factors, such as hypoglycemia and hyperventilation
- Atrial repolarization
- Ventricular conduction abnormalities and rhythms beginning in the ventricles
Figure 2: ECM Analysis, Record e0106, Lead V3 The ST segment is a darker shade of blue than the PR segment on the ECM, indicating more negative amplitude and the presence of ST depression.
- Klabunde, R. E. (2016). Electrocardiogram ST segment changes [Online image]. Retrieved July 20, 2016, from http://www.cvphysiology.com/CAD/CAD012.htm
- The ST Segment. (n.d.). Retrieved July 27, 2016, from http://lifeinthefastlane.com/ecg-library/st-segment/
- ST Segment Abnormalities. (n.d.). Retrieved August 05, 2016, from http://ecg.utah.edu/lesson/10
- European ST-T Database. (1992). Retrieved July, 2016, from https://physionet.org/physiobank/database/edb/
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