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Cardiology

Reentry Arrhythmia (Archived)

Reentry describes a self-sustaining cardiac rhythm abnormality. In reentry, the action potential propagates in a circus-like closed loop manner. It is a disorder of impulse conduction and thus describes one kind of arrhythmogenesis and is differentiated from disorders of impulse generation such as automaticity and triggered activity. First studies investigating reentry are over 100 years old and go back to Mines and Garrey. Dysrhythmias based on the reentry mechanism include atrial tachyarrhythm

v1 · Reviewed Nov 7, 2026 by Automated Clinical Reviewer (Strict Verbatim v1)
  • Ventricular tachyarrhythmias can cause sudden death in patients suffering from chronic heart failure.
  • Atrial fibrillation is associated with increased mortality due to three problems: thromboembolism causing stroke, decreased cardiac output due to atrioventricular synchrony, and irregular heartbeat.
  • If these fail or the patient is hemodynamically unstable cardioversion should be performed.
  • To evaluate arrhythmias, different types of ECG (surface 12-lead, Holter, event recorder, intracardiac) and finally electrophysiologic studies using targeted stimuli are available.
  • There are helpful ECG features to distinguish between AVNRT and AVRT.
  • The entrainment technique is required to diagnose reentry.
  • Mapping allows for identification of reentry circuit elements such as entry, exit, conduction barriers, bystanders, inner and outer loop, isthmus site, and zone of slow conduction (SCZ).
  • Electrophysiologic studies are indicated for supraventricular or ventricular tachycardias.
  • The A-H jump, which is a sudden increase of the atrial-hisian interval to more than 50ms with a prior stimulus, indicates dual AV node physiology and together with inducible tachycardia suggest AVNRT.
  • Antegrade AP conduction manifests in the ECG as Delta wave, short PQ interval, and QRS prolongation.
  • The surface ECG algorithm helps to localize the accessory pathway.
Brugada algorithm
using the QRS morphology in the precordial leads
Vereckei algorithm
based on QRS changes in lead aVR
  • Regular SVT should be treated with Valsalva maneuver and if unsuccessful with adenosine.
  • First-line therapy is the vagal maneuver.
  • Drugs of choice include adenosine, beta blockers such as esmolol, and calcium channel blockers such as verapamil or diltiazem.
Adenosine
Not specified in source
Adult
Not specified in source
Renal
Not specified in source
Duration
Not specified in source
  • If these fail or the patient is hemodynamically unstable cardioversion should be performed.
  • Ongoing treatment includes beta blocker, calcium channel blockers, and sodium channel blockers, amiodarone or digoxin depending on the kind of SVT.
  • The only curative treatment is ablation.
  • To target the fast pathway sodium channel blockers and amiodarone can be used.
  • If the reentry is associated with a short excitable gap, potassium channel blocking agents such as amiodarone can be used to lengthen the refractory period of the accessory pathway.
  • If the reentry is associated with a long excitable gap a sodium channel blocker may be chosen.
  • Otherwise, ablation of a narrow part of the reentry pathway such as the cavotricuspid isthmus (CTI) can erase the reentry arrhythmia.
  • Radiofrequency ablation has success rates of 97 to 100% to eradicate accessory pathways in AVRT.
  • Complications include inadvertent AV block and recurrence of arrhythmia.
  • Once ablation of CFAE is complete, proper conduction pattern can reorganize.
  • Reports of the long-term success of PVI are 50 to 60% in paroxysmal AF and less in persistent and permanent AF.
  • review
    Reentry Arrhythmia (Archived). StatPearls [Internet] — Amandeep Goyal, Hajira Basit, Poonam Bhyan, Roman Zeltser — StatPearls Publishing, 2023

Decision support only. Verify against local protocols and current labeling. Source: www.ncbi.nlm.nih.gov