define left axis deviation and its causes
The four main causes of left axis deviation (LAD): 1  Left anterior fascicular block (LAFB): 2  Diagnostic criteria include: 3  Mean QRS axis from - 45 to - 90 (possibly. 4  A qR pattern in lead aVL, with the R-peak time, i.e., the onset of the Q wave to the peak of the R wave. 5  45 msec (slightly more than one small box wide).
Answer: Left Axis Deviation (LAD) refers to the pattern of electrical activation that occurs in the heart. LAD is an EKG-specific finding and not necessarily indicative of any specific cardiovascular condition. In fact, LAD is the most common EKG abnormality observed in adults, occurring in almost 10% of the adult population.