The Three Fates Of PAC's-KH
Frank Yanowitz
Copyright 1996
As illustrated,PAC's can have three fates: PAC-1
enters the ventricles and encounters no conduction
delays, therefore causing a narrow QRS; PAC-2 occurs
a little earlier and can't get through the AV junction,
therefore being "nonconducted"; PAC-3 seen in
lead V1 makes it into the ventricles but
encounters the right bundle refractory period, therefore
conducting with a RBBB morphology; i.e. aberrant
conduction.