The screening mantra for waves of infarction: a quick and simple method for learning the widths of pathologic Q or R waves.
The 12-lead ECG shown below contains numbers corresponding to pathologic widths for Q waves and R waves for selected leads.
One can memorize the criteria above by using a simple scheme whose numbers represent the durations of Q waves or R waves which, if present, denote a pathologic wave (Q or R). Begin with lead V 1 and repeat the numbers in the box below in the following order. The numbers increase from "any" to 50.
| Q wave in lead V1, for anterior MI | |
| Q wave in lead V2, for anterior MI | |
| Q wave in lead V3, for anterior MI | |
| Q wave > 20 msec in lead V4, for anterior MI | |
| Q wave > 20 msec in lead V5, for apical MI | |
| Q wave > 20 msec in lead V6, for apical MI | |
| Q wave > 30 msec in lead I, for lateral MI | |
| Q wave > 30 msec in lead aVL, for lateral MI | |
| Q wave > 30 msec in lead II, for inferior MI | |
| Q wave > 30 msec in lead aVF, for inferior MI | |
| R wave > 40 msec in lead v1, for posterior MI | |
| R wave > 50 msec in lead v2, for posterior MI | |
Notice that leads III and aVR are not listed. This is because lead III may normally have Q waves that are both wide and deep and lead aVR may commonly have a wide Q wave.
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