A 42 y/o male presents c/o palpitations.
Q1. What does the EKG demonstrate?
A1. Sinus rhythm with PJC's
Premature junctional contractions (PJCs) are due to an ectopic pacemaker within the AV node or common AV bundle. The ECG characteristics of PJCs are:
- Ectopic P wave has a different shape and direction (usually inverted in leads II, III, and aVF)
- Ectopic P wave may occur before or after the QRS complex
- Shorter than normal PR interval
- Premature ectopic QRS complex
- Normal-shaped QRS complete
Because the sinus node is usually affected, the postectopic pause is not fully compensatory. A compensatory pause is seen if the PJCs do not conduct retrogradely. PJCs may be isolated, multiple (as in bigeminy or trigeminy), or multifocal. PJCs are uncommon in healthy hearts. They occur in CHF, digoxin toxicity, ischemic heart disease, and AMI (especially of the inferior wall). No specific treatment is usually required. Treat the underlying disorder.
(Piktel, Cardiac Rhythm Disturbances. In Tintinalli’s Emergency Medicine, 7th Ed. Ch. 22)