Table of Contents
left axis deviation (LAD)
introduction
aetiology
left axis deviation (LAD)
see also:
The basics of reading an ECG
right axis deviation (RAD)
introduction
left axis deviation is an ECG finding where the mean frontal QRS axis is between -30 deg to - 90deg
the normal QRS axis is -30deg to +90deg
aetiology
left ventricular hypertrophy (LVH)
LAD is suggestive of LVH when other features of LVH are present, but is an insensitive indicator of LVH
Left Bundle Branch Block (LBBB)
presence of LAD in LBBB suggests more severe conduction system disease that involves both the fascicles and the main bundle branch
left anterior fascicular block
by definition, there must be LAD of -45deg to -90deg for left anterior fascicular block (LAFB) to exist
inferior MI
a dominant Q wave in the inferior leads can lead to LAD
mechanical shifts of the heart:
pneumothorax
ectopic ventricular rhythms
new LAD is suggestive of
ventricular tachycardia (VT)
in
broad complex tachycardias