Does AVNRT have an accessory pathway?

People with AVNRT have episodes of an irregularly fast heartbeat (more than 100 beats per minute) that often start and end suddenly. The episodes are due to an extra pathway — called a reentrant circuit — located in or near the AV node that causes the heart to beat prematurely.

What is bystander accessory pathway?

An accessory pathway (AP) is an abnormal muscular connection between the atrium (A) and the ventricle (V). Its manifestations depend on several anatomic and electrophysiological factors. During sinus rhythm (SR) only AP able to preexcite the V will be manifested in the typical Wolff-Parkinson-White pattern (WPW).

Which pathway is ablated in AVNRT?

the slow pathway
Ablation of the slow pathway (SP) has become a simple procedure used to cure atrioventricular nodal re-entrant tachycardia (AVNRT). [1] This can usually be achieved by radiofrequency ablation of the SP region, anterior to the ostium of the coronary sinus, at the base of the triangle of Koch.

What is the slow pathway in AVNRT?

In the majority of cases of slow/fast AVNRT, which occurs in ≈90% of the patients, the anterograde slow pathway is formed by the rightward inferior extension of the atrioventricular node, which can be targeted for ablation with a low risk of atrioventricular block at the inferior triangle of Koch (between the tricuspid …

What is the difference between SVT and AVNRT?

Atrioventricular nodal reentrant tachycardia (AVNRT) is a regular supraventricular tachycardia (SVT) that results from the formation of a reentry circuit confined to the AV node and perinodal atrial tissue. Because of its abrupt onset and termination, AVNRT is categorized as a paroxysmal SVT (PSVT).

How can you tell the difference between AVRT and AVNRT?

In typical AVNRT, retrograde P waves occur early, so we either don’t see them (buried in QRS) or partially see them (pseudo R’ wave at terminal portion of QRS complex) In AVRT, retrograde P waves occur later, with a long RP interval > 70 msec.

What causes an accessory pathway?

Accessory pathways are a consequence of incomplete embryologic development of the AV annulus and sometimes may be genetic. Atrioventricular reentrant tachycardia (AVRT) is caused by macroreentry using a circuit that includes the atria, AV node, His-Purkinje conduction system, ventricles, and an accessory pathway.

What is accessory pathway tachycardia?

Patients who have an accessory pathway (AP) of atrioventricular (AV) conduction may develop circus movement tachycardia otherwise known as atrioventricular re-entrant tachycardia (AVRT). Orthodromic AVRT is the most common form.

What is more common AVRT or AVNRT?

Although AVNRT is the most common SVT in adults (approximately 50 to 60 percent),4 AVRT is most common in children (accounts for approximately 30 percent of all SVTs).