Atrioventricular Block During Upright Tilt Table Test

Abstract

Patients with a cardioinhibitory response (asystole or atrioventricular block [AVB]) during upright tilt table test (UTT) constitute a therapeutic challenge. Our present knowledge is partial and in those who experience AVB is absent. Furthermore, we ignore if there is any difference between both groups, particularly pacemaker indication. We aimed to study patients with a cardioinhibitory response during UTT and incidence of AVB during UTT, compared to asystole; plus the outcome during prolonged follow-up. Of 867 patients who underwent UTT, 172 were positive for a neurally mediated response, all with normal neurocardiovascular evaluation. Of the 172 patients, 6 (3.4%) developed AV block (group A), and 26 (15.1%) experienced asystole (group B). Group A included 6 women (100%), mean age 21 +/- 12 years. All patients in group A had sinus rate deceleration during AVB. Group B included 10 women (38%), mean age 28 +/- 17 years, and a mean pause of 15 +/- 9 seconds. We contacted 30 of 32 patients, mean follow-up of 45 +/- 38 months. Seven patients in group B had syncopal recurrences; five had 2 or more episodes. One patient from group B received a DDD pacemaker. In group A, one had one recurrence. No deaths were observed. AVB during UTT is rare, occurs in young women, and is always associated with sinus rate deceleration. Medium- to long-term prognosis is good, and equivalent to patients with asystole. There is no evidence that patients with AVB during UTT require a pacemaker implant.

A Review on Advanced Atrioventricular Block in Young or Middle‐Aged Adults

“…AV block provoked by tilt test represents the cardioinhibitory component of the neurocardiogenic reflex which is less frequent than sinus arrest, sinoatrial block, or sinus bradycardia (vagal stimulation on sinoatrial node usually predominates). Zysko et al reported an incidence of 5.2% of complete AV block in patients with positive tilt test, 77 similar to what had been previously found 78 . Sinus rhythm slowing or irregular sinus rhythm observed during (and sometimes preceding) the AV block due to neurocardiogenic reflex indicate its vagal origin.…”

Potential usage of cardioneuroablation in vagally mediated functional atrioventricular block

“…In another study, AVB was seen in 3.4% of patients with a neurally mediated response to tilt testing, mean age 21 ± 12 years. 10 A female predominance (74% and 100%, respectively) was detected in both studies. 9,10 Considering that up to 40% of the general population has experienced at least one episode of syncope in their lifetime and about 20% of all syncopes are reflex syncope, it may be speculated that vagally mediated functional AVB is not an uncommon but is an under-diagnosed clinical entity.…”

“…10 A female predominance (74% and 100%, respectively) was detected in both studies. 9,10 Considering that up to 40% of the general population has experienced at least one episode of syncope in their lifetime and about 20% of all syncopes are reflex syncope, it may be speculated that vagally mediated functional AVB is not an uncommon but is an under-diagnosed clinical entity. 1,11 Intrinsic and extrinsic idiopathic forms are usually characterized by recurrent syncope episodes with a duration of prodromal symptoms of ⩽5 s. 12,13 However, vagally mediated form is associated with well characterized prodromal symptoms such as nausea, feeling warm, a cold-clammy sweat, blurred vision, or lightheadedness prior to syncope which last longer than 5 s. 12,14 In reflex syncope, a potential trigger such as emotional stress, painful stimuli, or standing for long periods can be identified in the great majority of cases.…”

Atrioventricular conduction disturbances immediately after hepatic graft reperfusion and their outcomes in patients undergoing liver transplantation

“…The detailed ECG criteria included simultaneous slowing of the sinus rate with longer PP intervals; a blocked P wave generally preceded by a prolongation of the PR interval in 1 or more beats; possible ventricular asystole; and significant PR prolongation or Mobitz type 1 AV block before initiation of complete AV block . In the literature, vagally mediated AV block has been fortuitously seen during typical situations characterized by paroxysmal vagal overactivity, such as carotid sinus massage, tilt‐induced syncope, and spontaneous neurally mediated syncope . The typical feature of AV block related to the neurocardiogenic reflex provoked by the tilt test was a substantial slowing of the sinus rhythm and PR interval prolongation .…”