Step 9: Assess ST segments and T waves

Analysis and Interpretation of the Electrocardiogram

How to use this module

The 12 lead ECG

Waves and complexes

Intervals and segments

Approach to the ECG

Step 1: Determine the heart rate

Step 2: Measure important intervals

Step 3a: Calculate the electrical axis

Step 3b: Calculate the electrical axis

Step 3c: Calculate the electrical axis

Step 4: Evaluate the cardiac rhythm

Step 5: Inspect P waves for atrial enlargement

Step 6: Inspect QRS complexes for ventricular hypertrophy or low voltage

Step 7a: Inspect QRS complexes for bundle branch block or fascicular block

Step 7b: Inspect QRS complexes for bundle branch block or fascicular block

Step 7c: Inspect QRS complexes for bundle branch block or fascicular block

Step 7d: Inspect QRS complexes for bundle branch block or fascicular block

Step 7e: Inspect QRS complexes for bundle branch block or fascicular block

Step 8: Assess Q waves and determine significance

Step 9: Assess ST segments and T waves

Step 10: Measure QT interval for specific diagnoses

Printable version

Step 9: Assess ST segments and T waves

Assess the ST segment for the presence of elevations or depressions, together with T wave abnormalities. ST elevation can indicate the presence of conditions such as acute myocardial injury, Prinzmetal's (variant) angina, pericarditis, ventricular aneurysm or myocardial ischemia.

This ECG is from a patient with an acute inferior MI. Note the ST elevation in the inferior leads (II, III and aVF). The ECG also shows ST depression in leads V1, V2 and V3 - likely a result of reciprocal changes associated with the MI.

« Previous | Next »