Junctional Rhythms (DM)

Junctional Rhythms

AV junction, will assume the role of pacing the heart

What is the main characterisitic of junctional rhythms

P waves are inverted or negative due to retrograde impulse from AV node

Premature Junctional Contraction (PJC)

A single site in the AV junction or bundle of His/Purkinje System contracts earlier than the next anticipated complex of the underlying rhythm

When does the pause in PJC occur

SA node is depolarized by ectopic beat, a noncompensatory pause occurs

Characteristics of PJCs (5-step)

1. Rate is underlying rhtyhm w/ the PJC

2. Usually regular, expect for PJC

3. Inverted or absent P wave that appear before or after QRS

4. PR interval is usually < 0.12 sec if preceding, absent if following QRS

5. QRS are uniform and < 0.12 sec

PJCs

Junctional Escape Rhythms

SA node may fail to generate an impulse, or if rate falls below that of the AV node, then AV node will assume the role of pacemaker

Series of junctional escape beats occur

Junctional escape beat

Isolated junctional beat occurs

Causes of Junctional Escape Rhythm

SA Node Disease

Hypoxia

Increased vagal tone

Cardiac Drugs

Complete Heart Block

Characteristics of Junctional Escape Rhythm (5-step)

Rate = 40-60 bpm

Rhythm is regular unless isolated junctional escape beat

Inverted or Absent P waves before or after QRS

PR is < 0.12 sec before QRS or absent if P is after QRS

QRS are uniform and < 0.12 sec

Junctional Escape Rhythm

What causes Accelerated Junctional Rhythm

Hypoxia

Digitalis

Inferior Wall MI

Rheuamtic Fever

Accelerated Junctional Rhythms

increased automaticity in AV junction, causes junction to discharge impulses at faster rate than its intrinsic rate

Characterisitcs of Acclerated Junction Rhythm

Rate = 60-100 bpm

Rhythm is regular unless isolated junctional escape beat

Inverted or Absent P waves before or after QRS

PR is < 0.12 sec before QRS or absent if P is after QRS

QRS are uniform and < 0.12 sec

Acclerated Junction Rhythm

Junctional Tachycardia Rhythm

Rhythm that arises from AV junctional tissue at a rate of 100 to 180 BPM

paroxysmal junctional tachycardia rhythm

Junctional Tachycardia Rhythm that starts and ends abrupty

Causes of Junctional Tachycardia

Underyling ischemia heart disease

Frequent ingestion of stimulatnts

Anxeity

Hypoxia

Digitialis

Rheumatic Heart Disease

Charcteristics of Hunctional Tachycardia

Rate = 100-180 bpm

Rhythm is regular unless isolated junctional escape beat

Inverted or Absent P waves before or after QRS

PR is < 0.12 sec before QRS or absent if P is after QRS

QRS are uniform and < 0.12 sec

Junctional Tachycardia