Accelerated idioventricular rhythm

Background

Results when rate of an ectopic ventricular pacemaker exceeds sinus node
Usually benign,self limiting
Terminology
- Idioventricular rhythm: 20-40 bpm
- Accelerated idoventricular rhythm: 40-120 bpm
- Ventricular tachycardia: >120 bpm

Causes

Reperfusion phase of acute myocardial infarction (most common cause)
Beta-sympathomimetics (isoprenaline or adrenaline)
Drug toxicity, especially digoxin, cocaine and volatile anaesthetics such as desflurane
Electrolyte abnormalities
Cardiomyopathy
congenital heart disease
myocarditis
Return of spontaneous circulation (ROSC) following cardiac arrest
Athletic heart

Clinical Features

Asymptomatic or palpitations

Differential Diagnosis

Wide-complex tachycardia

Assume any wide-complex tachycardia is ventricular tachycardia until proven otherwise (it is safer to incorrectly assume a ventricular dysrhythmia than supraventricular tachycardia with abberancy)

Regular
- Monomorphic ventricular tachycardia
- PSVT with aberrant conduction:
  - PSVT with bundle branch block^
  - PSVT with accessory pathway
  - Atrial flutter with bundle branch block^
- Sinus tachycardia with bundle branch block^
- Accelerated idioventricular rhythm (consider if less than or ~120 bpm)
- Metabolic
  - Hyperkalemia
  - Digoxin toxicity
  - Severe metabolic acidosis
Irregular
- Atrial fibrillation/atrial flutter with variable AV conduction AND bundle branch block^
- Atrial fibrillation/atrial flutter with variable AV conduction AND accessory pathway (e.g. WPW)
- Atrial fibrillation + hyperkalemia
- Polymorphic ventricular tachycardia
  - Torsades de pointes
  - Nonsustained ventricular tachycardia

^Fixed or rate-related

Palpitations

Arrhythmias:
Non-arrhythmic cardiac causes:
Psychiatric causes:
- Panic attack
- Anxiety
- Somatic Symptom Disorder
Drugs and Medications:
- Alcohol
- Caffeine
- Drugs of abuse (e.g. cocaine)
- Medications (e.g. digoxin, theophylline)
- Tobacco
Misc

Evaluation

ECG features

Regular rhythm
Rate 50-110 bpm
Three or more ventricular complexes
QRS complexes >120ms
Fusion and capture beats

Management

AIVR is a benign rhythm in most settings and does not usually require treatment
Self limiting and resolves when sinus rate exceeds that of the ventricular foci
Antiarrhythmics may cause precipitous haemodynamic deterioration and should be avoided
Treat the underlying cause: e.g. correct electrolytes, restore myocardial perfusion
Patients with low-cardiac-output states (e.g. severe biventricular failure) may benefit from restoration of AV synchrony to restore atrial kick – in this case atropine may be trialled to increase sinus rate and AV conduction

Disposition

Normally outpatient

External Links

http://lifeinthefastlane.com/ecg-library/aivr/

References

This article is issued from Wikem. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.