Left bundle branch block and private pilot licensing.

Three otherwise healthy private pilots were licensed with the restriction to fly "as or with safety pilot" because of a left bundle branch block (LBBB). Whether a pilot with this conduction disturbance is allowed to fly unrestricted depends on invasive diagnostic procedures. Above age 40, cardiovascular risk in subjects with LBBB becomes high enough that a flying license should be withheld. A protocol for licensing in LBBB cases under age 40 is given, relying on non-invasive diagnostic procedures, taking into account intermittent occurrence, electrical axis, and duration of QRS complex.