Accelerated idioventricular rhythm

A type of cardiac arrhythmia

Accelerated idioventricular rhythm (AIVR) is a type of cardiac arrhythmia characterized by a ventricular rate that is faster than the normal intrinsic rate of the ventricles but slower than ventricular tachycardia. It is often considered a benign rhythm and is commonly observed in certain clinical situations.

Pathophysiology

AIVR occurs when the ventricular myocardium generates electrical impulses at a rate faster than the normal sinus rhythm but slower than ventricular tachycardia. This can happen due to enhanced automaticity of the ventricular pacemaker cells or due to a reentrant circuit within the ventricles. The typical rate of AIVR is between 50 and 110 beats per minute.

Clinical Significance

AIVR is often seen in the setting of myocardial infarction, particularly during the reperfusion phase following thrombolytic therapy or percutaneous coronary intervention. It can also occur in patients with digitalis toxicity, after cardiac surgery, or in association with other cardiac conditions.

Diagnosis

The diagnosis of AIVR is made using an electrocardiogram (ECG). The ECG will show a regular rhythm with wide QRS complexes, typically without preceding P waves. The rate is usually between 50 and 110 beats per minute, distinguishing it from ventricular tachycardia, which has a rate greater than 120 beats per minute.

Management

In most cases, AIVR is a self-limiting arrhythmia that does not require treatment. It often resolves spontaneously as the underlying condition improves. However, if AIVR is associated with hemodynamic instability or symptoms, treatment may be necessary. This can include the use of antiarrhythmic drugs or addressing the underlying cause of the arrhythmia.

Prognosis

The prognosis for patients with AIVR is generally good, especially when it occurs in the context of myocardial reperfusion. It is usually a transient phenomenon and does not typically lead to significant complications.

Related pages

• Ventricular tachycardia
• Myocardial infarction
• Electrocardiogram
• Cardiac arrhythmia

Gallery

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  Accelerated idioventricular rhythm from the left ventricle

Accelerated idioventricular rhythm

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  AIVR from the LV