ST Elevation

ECG Features

Figure 1: ECG Strip[1]

ST elevation and ST depression 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 elevation occurs when the ST segment is elevated in comparison to the PR segment. Specifically, the ST segment represents "the interval between ventricular depolarization and repolarization.''[2]

Clinical Significance[3]

  • 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:
    • Drugs
    • 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

ECM Features

See ST Segment Abnormalities for Figure 2 format explanation

Figure 2: ECM Analysis, Record e0114, Lead V4[4][5] The ST segment is a lighter shade of blue than the PR segment on the ECM, indicating more positive amplitude and the presence of ST elevation.

ECM Examples

Additional Information

References

  1. Silvey, N. (n.d.). Elevation of the ST segment [Online image]. Retrieved July 20, 2016, from http://www.nataliescasebook.com/tag/s-t-elevation
  2. The ST Segment. (n.d.). Retrieved July 27, 2016, from http://lifeinthefastlane.com/ecg-library/st-segment/
  3. ST Segment Abnormalities. (n.d.). Retrieved August 05, 2016, from http://ecg.utah.edu/lesson/10
  4. European ST-T Database. (1992). Retrieved July, 2016, from https://physionet.org/physiobank/database/edb/
  5. Goldberger AL, Amaral LAN, Glass L, Hausdorff JM, Ivanov PCh, Mark RG, Mietus JE, Moody GB, Peng C-K, Stanley HE. PhysioBank, PhysioToolkit, and PhysioNet: Components of a New Research Resource for Complex Physiologic Signals. Circulation101(23):e215-e220 [Circulation Electronic Pages;http://circ.ahajournals.org/cgi/content/full/101/23/e215]; 2000 (June 13).