Asystole Differential Diagnoses

Updated: Mar 31, 2020
  • Author: Sandy N Shah, DO, MBA, FACC, FACP, FACOI; Chief Editor: Barry E Brenner, MD, PhD, FACEP  more...
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Diagnostic Considerations

A bradyasystolic or asystolic arrest may be primary or secondary in a patient experiencing a myocardial infarction (MI). It may also be due to a failure of pacemaker generation or propagation directly because of ischemia to the sinoatrial (SA) node or the atrioventricular (AV) conducting system.

Many patients with myocardial infarction have some degree of autonomic disturbance (ie, high parasympathetic tone), resulting indirectly in bradydysrhythmias or heart block. A lack of responsiveness to sympathetic stimulation may also be present. Hypoxemia from pulmonary edema and/or poor tissue perfusion from cardiogenic shock could also lead to a secondary asystolic arrest.

Consider drug toxicity and hypoxia in the differential diagnosis. Also keep in mind that electrocardiograph (ECG) lead displacement may simulate asystole. Recheck the placement of all leads and check the patient's pulse to exclude this possibility.

Differential Diagnoses