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How to Measure the ST Segment of an ECG


Published: 02 June 2019

Cover image for article: How to Measure the ST Segment of an ECG

Ausmed Explains... How to Measure the ST Segment of an ECG

To determine the ST elevation, it is important to know where to measure the ST segment from.

For that, you need to find the J point. If you follow the QRS complex on your ECG, you will see that they are usually sharp-pointed.

If you go down with the Q wave, up with the R wave, down the S wave and follow the S wave back to the baseline, it will usually pass the baseline.

The moment that line goes horizontal, that is where your J point is.

You need to find the J point and then measure the distance between the baseline and the J point.

If that distance is more than two little blocks in the precordial leads (in other words, two millimetres) - or more than one little block in the limb leads (in other words, one millimetre) - then we say the ST segment is elevated.

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5 Total Rating(s)

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Melissa Boehme
08 Sep 2019


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Russell Stanistreet
05 Jul 2019

Excellent resource and one that compliments many articles that allow one to discuss openly with peers to further enhance and evaluate present and new knowledge.

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Gurmeet Albail singh
08 Jun 2019

Great short video to reinforce st segment identification and measurement

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Grazina Van Gaans
07 Jun 2019

Good basic information re cardiac monitoring.

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Rincy Sijo
06 Jun 2019