Chapter 6 Flashcards
What are atrial dysrhythmias caused by?
Ectopic impulses in either atria which affects the SA node and increases the heart rate
Ectopic impulses
Referes to an electrical impulse that comes from outside of the normal pacemaker site or electrical conduction pathway.
What dysrhythmias are caused by ectopic impulses?
Premature atrial complexes, atrial tachycardia, atrial flutter, and atrial fibrillation
Atrial dysrhythmias occur from conditions such as
Damage to the atria from MI, valvular problems, ot neurological influences
Which wave form is affected by the change in electrical activity within the atria?
P waves
What are premature atrial complexes (PAC)
Electrical impulses that originate in the atria and initiate an early impulse that interrupts the inherent regular rhythm. The atria do not achieve the maximum lood capacity prior to contraction, lack of blood causes low cardiac output and less volume in the ventricles prior to ventricular contraction.
PAC criteria for classification
A PAC is a cardiac complex that occurs too soon. It has a positively deflected P wave. Other than being “early”, this complex does not possess nay abnormal features
Biphasic
The waveform that has two phases; an equally positive (upward) and negative (downward) deflection on the ECG tracing
Trigeminy
Refers to a pattern in wich every third complex is a premature beat
How to determine a PAC
Determine the underlying rhythm of NSR, S.Brady, S.Tachy or S.Dys followed by a description of the PAC (ex: sinus rhythm with trigeminal PACs
Signs and sx’s
Those of low cardiac output, palpitations , depend on frequency of PACs
Wandering Atrial Pacemaker (WAP)
Rhythm in which the pacemaker site shifts between the SA node, atria, and/or the AV junction. P wave configuration changes in the same lead
When is WAP a normal finding?
WAP is a normal finding in children, older adults, and well-conditioned athletes
Signs and sx’s of WAP
None. May be related to some types of organic heart disease and drug toxicity
WAP criteria and classification
Has a changing P wave configuration with at least three variations in one lead. The rhythm may be irregular
Multifocal Atrial Tachycardia (MAT)
Has a P wave that changes from beat to beat and a heart rate of 101 to 150. It has the same characteristics as wandering atrial pacemaker (WAP), with the only difference being that the rate is in excess of 100.