Atrioventricular Nodal Reentry Tachycardia (AVNRT)

Author: Brian Olshansky, MD; Chief Editor: Jeffrey N Rottman, MD more...

Updated: Feb 28, 2012

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Background
Pathophysiology
Epidemiology
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Background

Atrioventricular nodal reentry tachycardia (AVNRT) is the most common type of reentrant supraventricular tachycardia (SVT). Because of the abrupt onset and termination of the reentrant SVT, the nonspecific term paroxysmal supraventricular tachycardia (or even the misleading term paroxysmal atrial tachycardia [PAT]) has been used to refer to these tachyarrhythmias. With improved knowledge of the electrophysiology of reentrant SVT, more specific nomenclature based on the mechanism of reentry helps in better classifying these arrhythmias and thus helps in choosing appropriate therapies.

Pathophysiology

The substrate for AVNRT may be functional rather than anatomic. These arrhythmias occur in young, healthy patients and in those with chronic heart disease.

In patients with atrioventricular (AV) nodal reentry, the AV node is functionally divided into 2 longitudinal pathways that form the reentrant circuit. In the majority of patients, during AVNRT, antegrade conduction occurs to the ventricle over the slow (alpha) pathway and retrograde conduction occurs over the fast (beta) pathway (see image below). In most patients with this arrhythmia, the tachycardia is initiated when an atrial premature complex is blocked in the fast pathway with a longer refractory period and conducts in the slow pathway with a shorter refractory period (see image below). While the impulse conducts to the ventricle in the slow pathway (antegrade conduction), the fast pathway recovers so that the impulse can conduct retrograde up the fast pathway to the atrium and the atrial end of the slow pathway (retrograde conduction).

Electrophysiological mechanism of atrioventricular nodal reentry tachycardia.

In approximately one third of patients, AVNRT is induced by premature ventricular stimulation. In addition to the typical mechanism of AV nodal reentry described above, atypical AV nodal reentry can occur in the opposite direction, with antegrade conduction in the fast pathway and retrograde conduction in the slow pathway. Less commonly, the reentrant circuit can be over 2 slow pathways, the so-called slow-slow AV nodal reentry.

Atypical atrioventricular nodal reentry tachycardia.

Typical atrioventricular nodal reentry tachycardia.

Frequency

United States

AVNRT occurs in 60% of patients (with a female predominance) presenting with paroxysmal SVT. The prevalence of SVT in the general population is likely several cases per thousand persons.

International

Frequency is similar to that in the United States.

Mortality/Morbidity

AVNRT is usually well tolerated; it often occurs in patients with no structural heart disease. In patients with coronary artery disease, AVNRT may cause angina or myocardial infarction. Prognosis for patients without heart disease is usually good.

Race

No known racial predilection exists.

Sex

More women than men have AVNRT.

Age

AVNRT may occur in persons of any age. It is common in young adults.

Proceed to Clinical Presentation

Contributor Information and Disclosures

Author

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 College of Cardiology, American Heart Association, Cardiac Electrophysiology Society, and Heart Rhythm Society

Disclosure: Guidant/Boston Scientific Honoraria Speaking and teaching; Medtronic Honoraria Speaking and teaching; Guidant/Boston Scientific Consulting fee Consulting

Coauthor(s)

Renee M Sullivan, MD Fellow, Division of Cardiovascular Medicine, University of Iowa Hospitals and Clinics

Renee M Sullivan, MD is a member of the following medical societies: American College of Cardiology, American College of Physicians, and American Medical Association

Disclosure: Nothing to disclose.

Specialty Editor Board

Russell F Kelly MD, Assistant Professor, Department of Internal Medicine, Rush Medical College; Chairman of Adult Cardiology and Director of the Fellowship Program, Cook County Hospital

Russell F Kelly is a member of the following medical societies: American College of Cardiology

Disclosure: Nothing to disclose.

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Medscape Salary Employment

Marschall S Runge, MD, PhD Charles and Anne Sanders Distinguished Professor of Medicine, Chairman, Department of Medicine, Vice Dean for Clinical Affairs, University of North Carolina at Chapel Hill School of Medicine

Marschall S Runge, MD, PhD is a member of the following medical societies: American Association for the Advancement of Science, American College of Cardiology, American College of Physicians-American Society of Internal Medicine, American Federation for Clinical Research, American Federation for Medical Research, American Heart Association, American Physiological Society, American Society for Clinical Investigation, American Society for Investigative Pathology, Association of American Physicians, Association of Professors of Cardiology, Association of Professors of Medicine, Southern Society for Clinical Investigation, and Texas Medical Association

Disclosure: Pfizer Honoraria Speaking and teaching; Merck Honoraria Speaking and teaching; Orthoclinica Diagnostica Consulting fee Consulting

Amer Suleman, MD Private Practice

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, 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.

Additional Contributors

The authors and editors of Medscape Reference gratefully acknowledge the contributions of previous coauthors Shamila Garg, MD, and Marina Hannen, MD, Chirag M Sandesara, MD, Mukesh Garg, MD, MRCP, Annette Quick, MD, and Marco A Barzallo, MD to the development and writing of this article.

References

Jackman WM, Beckman KJ, McClelland JH, et al. Treatment of supraventricular tachycardia due to atrioventricular nodal reentry, by radiofrequency catheter ablation of slow-pathway conduction. N Engl J Med. Jul 30 1992;327(5):313-8. [Medline].
Braunwald E, ed. Heart Disease: A Textbook of Cardiovascular Medicine. 7^th ed. Philadelphia, Pa: WB Saunders; 2004.
Fogoros RN. Electrophysiologic Testing (Practical Cardiac Diagnosis). 3^rd ed. London, UK: Blackwell Science; 1999.
Gursoy S, Steurer G, Brugada J, et al. Brief report: the hemodynamic mechanism of pounding in the neck in atrioventricular nodal reentrant tachycardia. N Engl J Med. Sep 10 1992;327(11):772-4. [Medline].
Janse MJ, Anderson RH, McGuire MA, Ho SY. "AV nodal" reentry: Part I: "AV nodal" reentry revisited. J Cardiovasc Electrophysiol. Oct 1993;4(5):561-72. [Medline].