AVNRT and AVRT Supraventricular Tachycardias
A patient guide to AVNRT and AVRT, including symptoms, ECG documentation, acute treatment and catheter ablation.
AVNRT and AVRT are regular, usually sudden-onset supraventricular tachycardias caused by an electrical re-entry circuit. AVNRT commonly uses two pathways within or close to the AV node. AVRT uses an additional electrical connection between the atria and ventricles.
Symptoms and Assessment
Episodes may cause a rapid regular heartbeat, chest discomfort, breathlessness, dizziness or, less commonly, fainting. A 12-lead ECG recorded during symptoms is particularly valuable. Intermittent episodes may require Holter or event monitoring. Structural heart disease and reversible triggers are assessed when clinically relevant.
Treatment and Follow-up
Stable episodes may terminate with clinician-taught vagal manoeuvres; urgent medical treatment is required when symptoms are severe or circulation is compromised. Catheter ablation can offer definitive treatment for recurrent or troublesome episodes. The pathway location, procedural benefit and small risk of injury to the normal conduction system are discussed individually.
Seek emergency help for persistent tachycardia with fainting, severe chest pain, marked breathlessness or signs of poor circulation.
Clinical Depth and Risk Assessment
Risk is not defined by the diagnostic label alone. Symptoms, ECG and rhythm findings, ventricular function, myocardial scar or structural change, family history, associated disease and previous events are integrated. Genetic results, when relevant, require expert interpretation; a variant of uncertain significance is not equivalent to a diagnosis.
Diagnostic Strategy and Limitations
Testing is selected to answer a specific question. ECG, ambulatory monitoring, echocardiography, cardiac MRI, CT, laboratory testing, exercise assessment or invasive evaluation have complementary roles. A normal test may not exclude an intermittent disorder, while an abnormal measurement must be checked against technical quality and clinical probability.
Treatment Decision Framework
Treatment may combine risk-factor control, condition-specific medicines, rhythm or heart-failure therapy, catheter procedures, surgery and implanted devices. These options address different mechanisms and are not automatically substitutes for one another. Expected benefit, uncertainty, procedural burden and the patient’s informed preferences should be discussed explicitly.
Long-Term Follow-up
Follow-up assesses symptoms, exercise capacity, rhythm burden, ventricular function and treatment tolerance over time. Family screening may be appropriate in inherited or suspected inherited disease. New fainting, sustained rapid rhythm, chest pain, neurological symptoms or rapidly worsening breathlessness requires urgent assessment.
Questions to Discuss With the Cardiology Team
- Which finding has the greatest influence on my present risk?
- Which test or treatment would genuinely change management?
- What symptoms should lead to an earlier appointment or emergency care?
- Do relatives need clinical or genetic assessment?
Medical Information Note
This page supports an informed discussion with the clinical team. It does not provide a personal diagnosis, medicine dose or sports-clearance decision.