eMedicine Specialties > Cardiology > Arrhythmias

Ashman Phenomenon: Differential Diagnoses & Workup

Author: Ram C Sharma, MD, MRCP, Assistant Professor of Medicine, Division of Cardiovascular Medicine, Department of Internal Medicine, University of Louisville
Coauthor(s): Roger Freedman, MD, Director of Clinical Cardiology, Professor, Department of Internal Medicine, Division of Cardiology, University of Utah School of Medicine
Contributor Information and Disclosures

Updated: May 29, 2009

Differential Diagnoses

Ventricular Premature Complexes
Ventricular Tachycardia

Other Problems to Be Considered

Understanding Ashman phenomenon is useful in differentiating wide complex arrhythmias of ventricular origin from supraventricular arrhythmias with aberrancy because the prognosis and treatment of these conditions are different.

A supraventricular impulse with aberrant conduction is confused with a PVC, and a series of consecutive aberrantly conducted supraventricular impulses may appear to be ventricular tachycardia.

Intermittent ventricular preexcitation, as in Wolf-Parkinson-White syndrome, should also be considered in the differential diagnosis of Ashman phenomenon.

Workup

Other Tests

  • Ashman phenomenon is diagnosed using a surface ECG (all 12 leads are best). In difficult cases, electrophysiological studies are required to establish whether the arrhythmia is of supraventricular or ventricular origin.
  • Fisch2 criteria for the diagnosis of Ashman phenomenon are as follows:
    • A relatively long cycle immediately preceding the cycle terminated by the aberrant QRS complex: A short-long-short interval is even more likely to initiate aberration. Aberration can be LBBB and RBBB, and both patterns may be observed even in the same patient.
    • RBBB-form aberrancy with normal orientation of the initial QRS vector: Concealed perpetuation of aberration is possible, such that a series of wide QRS supraventricular beats is possible.
    • Irregular coupling of aberrant QRS complexes
    • Lack of a fully compensatory pause (never seen in atrial fibrillation)
  • QRS morphology is the most helpful clue in differentiating between a supraventricular and ventricular origin of wide QRS complexes. The morphologic features that favor ventricular origin of wide complexes include the following:
    • LBBB morphology with slurred or notched downstroke in leads V1 or V2
    • RBBB morphology with monophasic R, biphasic QRS, or rSR' (ie, "rabbit ear") pattern in V1
    • QS pattern in V6
    • QRS duration longer than 140 milliseconds in RBBB morphology and QRS duration longer than 160 milliseconds in LBBB morphology
    • R-to-S interval longer than 100 milliseconds in a precordial lead
    • Marked left axis (between -90° and 180°)
  • Several studies by Marriott et al3 and Gulamhusein et al4 have analyzed His electrogram findings with simultaneous surface ECG findings and found low sensitivity and specificity of Ashman phenomenon for helping diagnose aberrancy versus ventricular rhythm.
  • Aberration may also be a sign of intermittent ventricular preexcitation via an accessory pathway, as may occur with Wolff-Parkinson-White syndrome.

More on Ashman Phenomenon

Overview: Ashman Phenomenon
Differential Diagnoses & Workup: Ashman Phenomenon
Treatment & Medication: Ashman Phenomenon
Follow-up: Ashman Phenomenon
Multimedia: Ashman Phenomenon
References
Further Reading
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References

  1. Gouaux JL, Ashman R. Auricular fibrillation with aberration stimulating ventricular paroxysmal tachycardia. Am Heart J. 1947;34:366.

  2. Fisch C. Electrocardiography of arrhythmias: from deductive analysis to laboratory confirmation--twenty-five years of progress. J Am Coll Cardiol. Jan 1983;1(1):306-16. [Medline].

  3. Marriott HJL, Sandler JA. Criteria, old and new, for differentiating between ectopic ventricular beats and aberrant ventricular conduction in the presence of atrial fibrillation. Prog Cardiovasc Dis. 1966;9:18.

  4. Gulamhusein S, Yee R, Ko PT, Klein GJ. Electrocardiographic criteria for differentiating aberrancy and ventricular extrasystole in chronic atrial fibrillation: validation by intracardiac recordings. J Electrocardiol. Jan 1985;18(1):41-50. [Medline].

  5. Adelstein EC, Saba S. Usefulness of baseline electrocardiographic QRS complex pattern to predict response to cardiac resynchronization. Am J Cardiol. Jan 15 2009;103(2):238-42. [Medline].

  6. Antunes E, Brugada J, Steurer G, et al. The differential diagnosis of a regular tachycardia with a wide QRS complex on the 12-lead ECG: ventricular tachycardia, supraventricular tachycardia with aberrant intraventricular conduction, and supraventricular tachycardia with anterograde conducti. Pacing Clin Electrophysiol. Sep 1994;17(9):1515-24. [Medline].

  7. Chaudry II, Ramsaran EK, Spodick DH. Observations on the reliability of the Ashman phenomenon. Am Heart J. Jul 1994;128(1):205-9. [Medline].

  8. Strabuzynska-Migaj E, Szyszka A, Cieslinski A. Prolonged QRS duration in patients with heart failure: relation to exercise tolerance, diastolic function and aetiology. Kardiol Pol. Dec 2008;66(12):1251-7. [Medline].

  9. Wagner GS. Ashman phenomenon. In: Wagner GS, Marriott HJ, eds. Marriott's Practical Electrocardiography. 9th ed. Baltimore, Md: Williams & Wilkins; 1994:340.

  10. Wellens HJ. The QRS configuration during bundle branch block. What has rate got to do with it?. Eur Heart J. Oct 2008;29(19):2319-20. [Medline].

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Keywords

aberrant ventricular conduction, aberrant conduction, right bundle-branch block morphology, RBBB morphology, intraventricular conduction abnormality, premature ventricular complexes, PVCs

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Contributor Information and Disclosures

Author

Ram C Sharma, MD, MRCP, Assistant Professor of Medicine, Division of Cardiovascular Medicine, Department of Internal Medicine, University of Louisville
Ram C Sharma, MD, MRCP is a member of the following medical societies: American Academy of Sleep Medicine, American College of Cardiology, and Royal College of Physicians of the United Kingdom
Disclosure: Nothing to disclose.

Coauthor(s)

Roger Freedman, MD, Director of Clinical Cardiology, Professor, Department of Internal Medicine, Division of Cardiology, University of Utah School of Medicine
Roger Freedman, MD is a member of the following medical societies: American College of Cardiology, American College of Physicians, American Heart Association, Heart Rhythm Society, Phi Beta Kappa, and Sigma Xi
Disclosure: St. Jude Medical Grant/research funds Other; St. Jude Medical Consulting fee Consulting; St. Jude Medical Ownership interest Other; Boston Scientific Grant/research funds Other; Boston Scientific Consulting fee Consulting; Medtronic Grant/research funds Other; Medtronic  Consulting; Sorin Consulting fee Consulting

Medical Editor

Russell F Kelly, MD, Program Director, Assistant Professor, Department of Internal Medicine, Division of Cardiology, Cook County Hospital, Rush Medical College
Russell F Kelly, MD is a member of the following medical societies: American College of Cardiology
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: Nothing to disclose.

Managing Editor

Brian Olshansky, MD, Professor of Medicine, Department of Internal Medicine, University of Iowa College of Medicine
Brian Olshansky, MD is a member of the following medical societies: American Autonomic Society, American College of Cardiology, American College of Chest Physicians, American College of Physicians, American College of Sports Medicine, American Federation for Clinical Research, American Heart Association, Cardiac Electrophysiology Society, Heart Rhythm Society, and New York Academy of Sciences
Disclosure: Guidant/Boston Scientific Honoraria Speaking and teaching; Medtronic Honoraria Speaking and teaching; Guidant/Boston Scientific Consulting fee Consulting; Reliant Grant/research funds Other; Novartis Honoraria Speaking and teaching; Novartis Consulting fee Consulting

CME Editor

Amer Suleman, MD, Consultant in Electrophysiology and Cardiovascular Medicine, Department of Internal Medicine, Division of Cardiology, Medical City Dallas Hospital
Amer Suleman, MD is a member of the following medical societies: American College of Physicians, American Heart Association, American Institute of Stress, American Society of Hypertension, Federation of American Societies for Experimental Biology, Royal Society of Medicine, and Society of Cardiac Angiography and Interventions
Disclosure: Nothing to disclose.

Chief Editor

Jeffrey N Rottman, MD, Professor of Medicine and Pharmacology, Director, Clinical Cardiac Electrophysiology Fellowship Program, Vanderbilt University School of Medicine; Chief, Department of Cardiology, Nashville Veterans Affairs Medical Center
Jeffrey N Rottman, MD is a member of the following medical societies: American Heart Association and North American Society of Pacing and Electrophysiology (NASPE)
Disclosure: Nothing to disclose.

 
 
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