Cardiology In Critical Care

Arrhythmia Recognition

Atrial Premature Beat (APB)

The impulse is discharged prematurely by some irritable focus in the atria giving rise to a distorted P wave (wide, narrow, notched, inverted or superimposed on the preceding T wave).  The further from the SA node the ectopic focus is, the more abnormal will be P' configuration.  PR interval normal or slightly prolonged.  Premature P followed by QRS less than 0.11 sec except when very premature P is not conducted; occasionally QRS may be wide with RBBB configuration due to aberrancy.  The pause between APB and the next sinus beat is usually noncompensatory, i.e., the RR interval between two QRS enclosing APB is less than twice the normal RR interval.

There have been Visitors to this website.

Return to Nurse Bob's™ Page