The deviation of ECG axis is generally affected by the anatomical position of the heart in the chest cavity, the mass ratio of the two ventricles, the function of the conduction system in the ventricle, the excessive conduction speed of excitement in the ventricle, age, body shape and other factors.
Left ventricular hypertrophy, left posterior branch block, etc. It can make the ECG axis shift to the left, and lanky people generally have left deviation.
The left deviation of ECG axis is not as significant as the right deviation.