• Left axis deviation (³ -30 degrees) is the most common "abnormality" in adults occurring in over 8%. It can be part of the criteria for LVH but in isolation it has little significance.

• Marked LAD (³ -45 degrees) is called left anterior hemiblock or left anterior fascicular block.

If left axis deviation is present, make sure that the patient does not have hypertension in multiple clinical circumstances including under stress. If noted to be borderline, this may prove to be an indication for ambulatory BP monitoring. Also, check for borderline indicators of LVH (i.e., the voltage criteria and left atrial enlargement). Note whether diagnostic inferior Q waves are present since an inferior MI can cause LAD.