Atrioventricular reentrant tachycardia

AVRT

Atrioventricular reentrant tachycardia (AVRT) is a type of supraventricular tachycardia (SVT) characterized by an abnormal electrical circuit in the heart that involves the atrioventricular node and an accessory pathway. This condition leads to episodes of rapid heart rate, which can cause symptoms such as palpitations, dizziness, and shortness of breath.

Pathophysiology

AVRT occurs due to the presence of an accessory pathway, which is an abnormal electrical connection between the atria and the ventricles. This pathway allows electrical impulses to bypass the normal conduction system of the heart, leading to a reentrant circuit. The most common type of AVRT is Wolff-Parkinson-White syndrome (WPW), where the accessory pathway is known as the Bundle of Kent.

Types

There are two main types of AVRT:

• Orthodromic AVRT: The electrical impulse travels down the atrioventricular node and returns to the atria via the accessory pathway.
• Antidromic AVRT: The electrical impulse travels down the accessory pathway and returns to the atria via the atrioventricular node.

Symptoms

Common symptoms of AVRT include:

• Palpitations
• Dizziness
• Shortness of breath
• Chest pain
• Syncope

Diagnosis

AVRT is typically diagnosed using an electrocardiogram (ECG), which can show characteristic findings such as a short PR interval and a delta wave in the case of WPW syndrome. Electrophysiological study (EPS) may also be performed to map the electrical pathways in the heart.

Treatment

Treatment options for AVRT include:

• Vagal maneuvers: Techniques such as the Valsalva maneuver or carotid sinus massage can help terminate the tachycardia.
• Medications: Antiarrhythmic drugs such as adenosine, beta-blockers, or calcium channel blockers may be used.
• Catheter ablation: A procedure that involves destroying the accessory pathway to prevent recurrence of the tachycardia.

Prognosis

The prognosis for individuals with AVRT is generally good, especially with appropriate treatment. Catheter ablation has a high success rate and can often cure the condition.

Related Pages

• Supraventricular tachycardia
• Wolff-Parkinson-White syndrome
• Atrioventricular node
• Electrocardiogram
• Catheter ablation