University:
West Coast University
Course:
NURS 110 | Introduction to Professional Nursing
Academic year:

2021
Views:

158

Pages:

1
Author:

Corey Garrison

Junctional Rhythm Rate: 40-60 BPM PRI: Absent or variable QRS: Usually < .12 may be wider depending on pacer site. QT: < .40 may be prolonged with slower heart rates Rhythm: Regular Source of pacer: AV Node/Junction/Bundle of HIS Characteristics: The AV node is a group of specialized cells and its main function is to delay impulses coming from the atria to ventricles, thereby allowing the atria more time to completely contract. Between the AV node and the right and left bundle branches lies the Bundle of His. The area around the Bundle of His is also called the AV junction (where the AV node and the bundles junction together). This AV junction can function as a pacemaker. It initiates impulses at a rate of 40 to 60 beats per minute. Under normal circumstances, the sinus node pacemaker is faster and predominates. If the AV node is not depolarized by the arrival of a sinus impulse within approximately 1.0 to 1.5 seconds, it will initiate an impulse of its own from this junctional area. This is called a junctional escape complex. It occurs because of failure of the sinus node to initiate an appropriately timed impulse or because of a conduction problem between the sinus node and the AV junction. A repeated series of such impulses is referred to as a junctional escape rhythm. Unusual or Absent P waves: If the AV junction paces the heart, the atria may or may not be stimulated. The electrical impulse must travel in a backward (retrograde) direction to activate the atria. In Leads II, III, and aVF, the P wave will be negative (inverted) if the atria are stimulated. Depending on how the atria responds to the junctional pacemaker, the patient could have a) no P waves; b) an inverted P wave (upside down just preceding the QRS); or c) an inverted P wave after the QRS (if atrial depolarization occurs after the QRS).. Causes: Electrolyte imbalance, sick sinus syndrome, digitalis toxicity, interior-wall MI, rheumatic heart disease, hypoxemia. Nursing Priorities: Check your patient’s blood pressure, assess for syncope, palpitations, or SOB. Lower blood pressure may result from loss of atrial kick and bradycardic Potential Treatments: Observation, Find and treat reversible causes, temporary or permanent pacer, atropine 0.5 – 1.0mg may cause the SA Node to overdrive the AV Node and increase the heart rate. Treatment is only needed if the patient is hypotensive or presents with hemodynamic instability.