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Simple atrioventricular (AV) dissociation or AV dissociation caused by third degree AV block?

One of the most difficult decisions for many physicians and advanced practice providers occurs when having to distinguish between simple atrioventricular (AV ) dissociation and AV dissociation caused by a third degree AV block. Third degree AV block is only one cause of AV dissociation and it is a very infrequent cause. The majority of simple AV dissociations are caused by variations in the balance of sympathetic and parasympathetic inputs from the autonomic nervous system. All of us probably experience an occasional episode of simple AV dissociation while we are asleep. Treatment for simple AV dissociation may be as simple as having the patient get out of bed and walk around the room a few times,…

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Articles of Interest

AV Dissociation Is a Symptom, Not a Diagnosis And other tips for reading ECGs

You cannot diagnose third-degree AV block based on AV dissociation alone…there are too many other reasons for AV dissociation.

A Reappraisal of Atrioventricular Dissociation

FOR many years confusion has existed rgarding the precise definition and terminology of atrioventricular (A-V) dissociation. There are many publications relating to the subject. Cushny,1) in 1897, first demonstrated digitalis-induced A-V dissociation experimentally in the dog.

Atrioventricular Dissociation: An Overview

Atrioventricular dissociation or AV refers to a group of heart rhythm abnormalities called arrhythmias, where self-sufficient pacemakers take hold of atria and ventricles. The SA node, or the sinoatrial node, is the primitive location in the atrium that starts a heartbeat. The AV node, or the atrioventricular node, controls the electrical signals of the heart that pass from the atrium to the ventricles. The HPS or the His-Purkinje system is in charge of the electrical impulse conduction in the ventricles. Thus, a typical cardiac circuit is activated Interference in this pathway leads to dissociation of the impulse transmission of the atria and ventricles. When this happens, multiple cardiovascular conditions arise.

Inferior-posterior Wall M.I. and AV Dissociation

The rhythm is interesting and not uncommon in the setting of inferior wall M.I. The atrial rate is about 158 bpm and the P waves are regular. (Marked in red on accompanying rhythm strip). Some P waves are hidden in T waves or ST segments, but we can see fragments of them.

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StatPearls

Atrioventricular dissociation is usually transient unless it includes a complete heart block in its definition. The prognosis of AV dissociation is dependent on the cause of the insult, rather than the effect of the AV dissociation itself. Often with the elimination of the causative insult, there is a complete recovery in patients.