Premature Atrial ectopic Beat

• The P wave occurs earlier than anticipated on the basis of observation of the preceding P-P intervals
• The P wave differs in morphology from the P wave of the Sinus Beat
• The P-R interval may be slightly longer or shorter than normal or can be entirely normal
• The QRS complex, S-T segment and T waves of the ectopic beats are similair of identical to those of the normal sinus beats
• The R-R interval immediately after the ectopic beat is slightly longer than the interval of the sinus beats unless there is a subtstantial reduction in the P-R interval of the ectopic beat. The increment length is not sufficient to be "compensatory"