The anteroseptal STEMI ECG example below is good enough to call ... This MI involves ST segment elevation in the inferior leads II, III and aVF and only requires 1 mm in 2 contiguous leads.

Note that the first three account for almost 90% of ECG tracings with LAD. If the QRS is predominantly negative in lead I and positive in lead aVF, then the axis is rightward (right axis deviation).

She returns for a follow-up visit for palpitations, and a 12-lead ECG is obtained ... 0° and +90° (positive QRS complex in leads I and aVF). The QT/QTc intervals are normal (280/440 msec).

Figure 2: An ECG obtained from a beagle dog 21 days later, showing six rhythm strips simultaneously (leads I, II, III, aVR, aVL and aVF). VPCs are the most frequent type of abnormal rhythm in dogs ...