left anterior fascicular block
An EKG/ECG finding (see above) defined as a QRS axis between –45º and –90º and a QRS duration of < 0.12 seconds in absence of left ventricular hypertrophy, inferior wall myocardial infarction and ventricular preexcitation of the baseline EKG. It is seen in about 4% of acute myocardial infarcts.
While LAFB has been considered a benign EKG finding, epidemiologic data suggest that it may be associated with an increased risk of atrial fibrillation, congestive heart failure, hypertensive heart disease, aortic valve disease, cardiomyopathies, myocardial fibrosis and death.
References JAMA 2013; 309:1587-1588