An interesting cause of wide complex tachycardia: Ashman's phenomenon in atrial fibrillation.
BACKGROUND
Ashman's phenomenon is an aberrant intraventricular conduction abnormality that occurs in response to a change in QRS cycle length. In atrial fibrillation, Ashman's phenomenon will present as a long RR cycle followed by a short RR cycle, with the subsequent QRS complex manifesting a right bundle branch block morphology. This morphologic variation can create difficulty with electrocardiographic interpretation, and can alter management in patients with this dysrhythmia.


OBJECTIVE
This report presents a case, describes the Ashman's phenomenon in atrial fibrillation, and discusses interpretation of this electrocardiographic finding.


METHODS
This is a 27-year-old woman who presented with palpitations and chest pain. The patient was symptomatic with a heart rate >200 beats/min and a wide complex tachycardia on electrocardiogram.


CONCLUSIONS
Ashman's phenomenon should be suspected in atrial fibrillation when there is a long cycle followed by a short cycle, with the subsequent QRS complex manifesting a right bundle branch block pattern. Emergency physician awareness of this phenomenon may improve diagnostic certainty and have an impact on dysrhythmia management.
Department of Emergency Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania.
Richard A
RA
Harrigan
Manish
M
Garg
D000328:Adult; D001281:Atrial Fibrillation / Q000150:complications* / Q000503:physiopathology; D005117:Cardiac Complexes, Premature; D004562:Electrocardiography; D005260:Female; D006801:Humans; D013610:Tachycardia / Q000209:etiology* / Q000503:physiopathology
Ashman’s phenomenon; aberrant conduction; atrial fibrillation; electrocardiogram; right bundle branch block