EKG chapter 9

Junctional Rhythms arise from the

AV Junction

AV junction

the tissue located between the right atrium and ventricle surrounding the AV node

Antigrade

Forward, towards the ventricle

Retrograde

Backwards, toward the atria

What regions can the AV junctional area be divided into?

High, Mid, low

High junctional Rythms

inverted p wave before qrs

Mid junctional Rhythms

No visible P waves

Low junctional Rhythms

inverted p waves following the qrs

Junctional Rhythms are seen ___ often than sinus or atrial rhythms.

Less

AV inherent rate

40 - 60 bpm

Treatment is aimed toward alleviating the _____ of the junctional rhthym

cause

For Junctional rythms More active treatment is not necessary unless ______ _______

Symptoms develop

For junctional Rhythms the goal of treatment is...

to return the sinus node to control or to return heart rate to more normal levels

QRS in junctional Rhythms can be...

both positive or negative

Premature Junctional Complexes (PJC)

Premature beats that originate in the AV junction before the next sinus beat is due

What is the cause of PJC?

Irritable tissue in the AV junction firing and usurping the sinus node for that beat

PJC rate

can occur at any rate

PJC regularity

Regular but interrupted

Pwave of PJC

inverted before or after the QRS or hidden inside the QRS

PR Interval of PJC

less than 0.12 if the P wave precedes the QRS

PJC effect

Usually no ill effects

Treatment PJC

usually none except for removal of the cause

Junctional Bradycardia

A junctional rhythm with a heart rate slower than usual

In a Junctional Bradycardia a _____ pacemaker has failed and the __ ______ has to escape to save patients life.

higher, AV junction

Junctional Bradycardia rate

less than 40

Junctional Bradycardia Regularity

Regular

Junctional Bradycardia P waves

inverted before or after the QRS or hidden inside the QRS

Causes of Junctional Bradycardia

vagal stimulation, hypoxia, ischemia of sinus node, heart disease

Effects of Junctional Brady

Decreased cardiac output

Junctional Rhythm Regularity

Regular

Treatment of Junctional Rhythm

Transcutaneous pacing, atropine, dopamine etc

The location of the P wave of Junctional rhythm is dependant on...

the region of the AV junction in which thr impulse originates

Accelerated Junctional Rhythm

can occur because of escape or usurpation.

Accelerated Junctional Rhythm Rate

60-100

Accelerated Junctional Rhythm Regularity

Regular

Cause of Accelerated Junctional Rhythm

Heart disease, stimulant drugs, caffiene

Accelerated Junctional Rhythm Effects

usually none

Junctional Tachycardia

An irritable spot in the AV junction has taken over as the pacemaker and the heart rate is very rapid. usually a result of usurpation

Junctional Tachycardia is best called ___ if there are no visible - ---- .

SVT, P waves

Junctional Tachycardia rate

greater than 100

Junctional Tachycardia REGULARITY

regular

Junctional Tachycardia cayses

digitalis toxicity, heart disease, stimulants, sympathetic nervous system stimulation

Junctional Tachycardia effects

decreased cardiac output

Junctional Tachycardia treatment

beta blockers, calcium channel blockers etc