This document discusses various dysrhythmias originating in the ventricles, including ventricular escape complexes/rhythms, accelerated idioventricular rhythm, premature ventricular contractions, ventricular tachycardia, torsades de pointes, ventricular fibrillation, asystole, and artificial pacemaker rhythm. For each dysrhythmia, the etiology, clinical significance, and treatment approach are summarized.

1. Dysrhythmias Originating
in the Ventricles
 Ventricular escape
complexes and
rhythms
 Accelerated
idioventricular rhythm
 Premature ventricular
contraction
 Ventricular tachycardia
 Torsades de pointes
 Ventricular fibrillation
 Asystole
 Artificial pacemaker
rhythm

2. Dysrhythmias Originating
in the Ventricles
>0.12 seconds, bizarreQRS
NonePRI
NoneP Waves
Ventricle
Pacemaker
Site
Escape complex, irregular;
escape rhythm, RegularRhythm
15–40Rate
Ventricular Escape Complexes
and Rhythms
Rules of Interpretation

3. Dysrhythmias Originating
in the Ventricles
 Ventricular Escape Complexes and Rhythms
 Etiology
 Safety mechanism to prevent cardiac standstill
 Results from failure of other foci or high-degreeAV block
 Clinical Significance
 Decreased cardiac output, possibly to life-threatening levels
 Treatment
 For perfusing rhythms, administer atropine and/orTCP
 For nonperfusing rhythms, follow pulseless electrical activity
(PEA) protocols

4. Dysrhythmias Originating
in the Ventricles
>0.12 seconds,
bizarre
QRS
NonePRI
NoneP Waves
Ventricle
Pacemaker
Site
Escape complex,
irregular;
escape rhythm, Regular
Rhythm
60-100Rate
Accelerated Idioventricular
Rhythm
Rules of Interpretation

5. Dysrhythmias Originating
in the Ventricles
 Accelerated Idioventricular Rhythm
 Etiology
 A subtype of ventricular escape rhythm that frequently occurs
with MI
 Ventricular escape rhythm with a rate of 60–110
 Clinical Significance
 May cause decreased cardiac output if the rate slows
 Treatment
 Does not usually require treatment unless the patient becomes
hemodynamically unstable
 Primary goal is to treat the underlying MI

6. Dysrhythmias Originating
in the Ventricles
>0.12 seconds, bizarreQRS
NonePRI
NoneP Waves
VentriclePacemaker Site
Interrupts regular
underlying rhythm
Rhythm
Underlying rhythmRate
Premature Ventricular Contractions
Rules of Interpretation

7. Dysrhythmias Originating
in the Ventricles
 PrematureVentricular Contractions
 Etiology
 Single ectopic impulse resulting from an irritable focus in
either ventricle
 Myocardial ischemia, increased sympathetic tone, hypoxia,
idiopathic causes, acid-base disturbances, electrolyte
imbalances, or as a normal variation of the ECG
 May occur in patterns
 Bigeminy, trigeminy, or quadrigeminy
 Couplets and triplets

8. Dysrhythmias Originating
in the Ventricles
 PrematureVentricular Contractions
 Clinical Significance
 Malignant PVCs
 More than 6/minute, R onT phenomenon, couplets or runs of
ventricular tachycardia, multifocal PVCs, or PVCs associated with
chest pain
 Ventricles do not adequately fill, causing decreased cardiac
output

9. Dysrhythmias Originating
in the Ventricles
 PrematureVentricular Contractions
 Treatment
 Nonmalignant PVCs do not usually require treatment in
patients without a cardiac history
 Cardiac patient with nonmalignant PVCs
 Administer oxygen and establish IV access
 Malignant PVCs:
 Lidocaine 1.0 –1.5 mg/kg IV bolus
 Repeat doses of 0.5-0.75 mg/kg to max dose of 3.0 mg/kg
 If PVCs are suppressed, administer lidocaine drip 2–4 mg/min
 Reduce the dose in patients with decreased output or decreased
hepatic function and patients >70 years old

10. Dysrhythmias Originating
in the Ventricles
>0.12 seconds,
bizarre
QRS
NonePRI
If present, not
associated with
QRS
P Waves
Ventricle
Pacemaker
Site
Usually regularRhythm
100–250Rate
Ventricular Tachycardia
Rules of Interpretation

11. Dysrhythmias Originating
in the Ventricles
 VentricularTachycardia
 Etiology
 3 or more ventricular complexes in succession at a rate of >100
 Causes include myocardial ischemia, increased sympathetic
tone, hypoxia, idiopathic causes, acid-base disturbances, or
electrolyte imbalances
 VT may appear monomorphic or polymorphic
 Torsade’s De Pointes
 Clinical Significance
 Decreased cardiac output, possibly to life-threatening levels
 May deteriorate into ventricular fibrillation

12. Dysrhythmias Originating
in the Ventricles
 Torsades de pointes
 PolymorphicVT

13. Dysrhythmias Originating
in the Ventricles
 Torsades de pointes
 Typically occurs in nonsustained bursts
 ProlongedQT interval during “breaks”
 QRS rates from 166–300
 RR interval highly variable
 Treatment
 Do not treat as standardVT
 Administer magnesium sulfate 1–2 g diluted in 100 ml D5W
over 1–2 minutes
 Overdrive pacing

14. Dysrhythmias Originating
in the Ventricles
NoneQRS
NonePRI
Usually absentP Waves
Numerous
ventricular foci
Pacemaker
Site
No organized
rhythm
Rhythm
No organized
rhythm
Rate
Ventricular Fibrillation
Rules of Interpretation

15. Dysrhythmias Originating
in the Ventricles
 Ventricular Fibrillation
 Etiology
 Wide variety of causes, often resulting from advanced
coronary artery disease
 Clinical Significance
 Lethal dysrhythmia with no cardiac output and no organized
electrical pattern

16. Dysrhythmias Originating
in the Ventricles
 Ventricular Fibrillation
 Treatment
 InitiateCPR
 Defibrillate with 200, 300 and 360 J (or biphasic equivalent)
 Control the airway and establish IV access
 Administer epinephrine 1:10,000 every 3–5 minutes
 Consider 40 IUVasopressin IV (one time only)
 Consider second-line drugs
 Amiodarone
 Lidocaine
 Provide continuous compressions

17. Dysrhythmias Originating
in the Ventricles
AbsentQRS
AbsentPRI
AbsentP Waves
No Electrical
Activity
Pacemaker
Site
No Electrical
Activity
Rhythm
No Electrical
Activity
Rate
Asystole
Rules of Interpretation

18. Dysrhythmias Originating
in the Ventricles
 Asystole
 Etiology
 Primary event in cardiac arrest, resulting from massive
myocardial infarction, ischemia, and necrosis
 Final outcome of ventricular fibrillation
 Clinical Significance
 Asystole results in cardiac arrest
 Poor prognosis for resuscitation

19. Dysrhythmias Originating
in the Ventricles
 Asystole
 Treatment
 Administer CPR and manage the airway
 Treat for ventricular fibrillation if there is any doubt about the
underlying rhythm
 Administer medications:
 Epinephrine

20. Dysrhythmias Originating
in the Ventricles
>0.12 seconds,
bizarre
QRS
If present, variesPRI
None produced by
ventricular pacemakers;
pacemaker spike
P Waves
Depends upon
electrode placement
Pacemaker
Site
May be regular or
irregular
Rhythm
Varies with
pacemaker
Rate
Artificial Pacemaker
Rules of Interpretation

21. Dysrhythmias Originating
in the Ventricles
 Artificial Pacemaker Rhythm
 Etiology
 Single vs. dual chamber pacemakers
 Fixed-rate vs. demand pacemakers
 Clinical Significance
 Used in patients with a chronic high-grade heart block, sick
sinus syndrome, or severe symptomatic bradycardia

22. Dysrhythmias Originating
in the Ventricles
 Artificial Pacemaker Rhythm
 Problems with Pacemakers
 Battery failure
 “Runaway” pacers
 Displaced leads
 Management Considerations
 Identify patients with pacemakers
 Treat the patient
 Use of a Magnet