Chapter 7 Flashcards
Junctional Dysrhythmias
Involves the AV junction/node/tissue. Abnormal. AV node rate of 40-60 bpm. Junctional rhythms are a result of electrical impulses coming fromt the AV node rather than form the SA node. As a result of the electrical activity coming formt he AV node or junction, the electrical impulses causing depolarization of the atria are flowing retrograde, or backward.
What is unique in the ECG of junctional dysrhythmias
An inverted O wave morphology
What is suggestive in junctional dysrhythmias
More serious conditions with electrical conduction system
Premature Junctional Complex (PJC)
A single early electrical impulse that originates in the atrioventricular junction. It occurs before the next expected sinus impulse, causing an irregularity in the underlying rhythm
PJC criteria for classification
PJC will cause the rhythm to be irregular, and the P wave may appear before, during, r after the QRS complex. Regardless of location, if the P wave is seen, it will be inverted.
Signs and sx’s of PJCs
When a pt is healthy there are none, when it occurs more that four to six per minute, this warns of amore serious condition and the pt may experience hypotension due to low cardiac input
Junctional Escape Rhythm
Also called junctional rhythm, originates at AV junctional tissue (not the SA node), producing retrograde depolarization of atrial tissue, and at the same time, stimulates the depolarization of ventricles.
Junctional escape rhythm criteria for classification
The P wave may occur before, during (buried), or after the QRS. If the P wave is seen, it will be inverted. The hr is between 40-60 bpm
Signs and sx’s of junctional escape rhythm
Slow hr than nl, loses the atrial kick due to the shortening of the interval between the atrial depolarization and ventricular depolarization. Hypotension, AMS, confusion, disorientation.
Junctional Tachycardia
Share the same unique morphology as junctional escape rhythm and accelerated junctional rhythm, the only difference again being the hr is FASTER in junctional tachy
Junctional Tachycardia criteria for classification
May have an inverted or absent P wave or P wave that follows the QRS complex. Hr is between 100 and 150 bpm
Signs and sx’s of pt with junctional tachycardia
Depend on the rate. Sx’s of low cardiac output, palpitations, if pt has a hx of similar heart conditions, this is more serious.
Tx for junctional tachycardia
Monitoring of ECT tracings, medication to treat dysrhythmias
Supraventricular Tachycardia (SVT)
Classification of rapid heartbeats occurring at a rate greater than 150 bpm. Not specifically a junctional dysrhythmia, but the origin causing the rapid heart rhythm may come from any location “above the ventricles”. NON SPECIFIC, electrical impulse may come form the sinus node, atria or AV junction. Atria contract as soon as the ventricles are relaxing.
P wave in SVT
Difficult to identify, (atrial contraction) they occur at the same time as the QRS or T waves (ventricle relaxation).
Dysrhythmias associated with SVTs (re-entry dysrhythmias)
Sinus tachycardia: Sinus node
Atrial flutter and Atrial fibrillation: Atrium
Junctional tachycardia: Junctional
What can we do to make it easier to identify the type of re-entry dysrhythmia
Sleep up the paper of the ECG, it will help determine the P wave and the origine of the dysrhythmia
SVT criteria for classification
Normal-narrow-appearing QRS complex and a rate of greater than 150 bpm
Signs and sx’s in SVT
The stable pt may only complain of palpitations.
The unstable pt may experience sx’s of low cardiac output which are reflective of the heart not pumping effectively to other body systems
Tx for SVTs
SVT increases myocardial oxygen demand, pt should be given oxygen asap.
Identify premature junctional complex using the criteria for classification, and explain how the rhythm may affect the pt, including basic pt care and tx
A premature junctional complex (PJC) is a single early electrical impulse that originates in the AV junction. It occurs before the next expected sinus impulse, causing an irregularity in the rhythm
Identify junctional escape rhythm using the criteria for classification, and explain how the rhythm may affect the pt, including basic pt care and tx
Junctional rhythm, also known as junctional escape rhythm, originates at AV junctional tissue, producing retrograde depolarization of atrial tissue, and at the same time, stimulates the depolarization of ventricles
Identify accelerated junctional rhythm using the criteria for classification, and explain how the rhythm may affect the pt, including basic pt care and tx
Accelerated junctional rhythm shares the same unique morphology as junctional escape rhythm, with the distinguishing difference being the hr, which is between 60-100 bpm for accelerated junctional rhythm
Identify junctional tachycardia using the criteria for classification, and explain how the rhythm may affect the pt, including basic pt care and tx
Junctional tachycardia rhythm shares the same unique morphology as junctional escape rhythm and accelerated junctional rhythm, the only difference again being the hr exceeds 100 bpm
