Variable Clinical Features and Ablation of Manifest Nodofascicular/Ventricular Pathways

Hoffmayer, Kurt S.; Lee, Byron K.; Vedantham, Vasanth; Bhimani, Ashish A.; Cakulev, Ivan; Mackall, Judith A.; Sahadevan, Jayakumar; Rho, Robert W.; Scheinman, Melvin M.

doi:10.1161/circep.114.001924

Cited by 37 publications

(42 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Only programmed atrial stimulation at shorter S1-S2 intervals could dissociate the anterograde conduction over the AP and AV node and consequently demonstrate the change in preexcitation degree, strongly supporting the presence of a NV fiber. 1,3 Besides, RV apical activation did not precede δ-wave onset, ruling out an atriofascicular type Mahaim fiber. 2 A preexcited junctional beat excluded all AV bypass tracts, including atriofascicular pathways.…”

Section: Nature Of Anterograde Preexcitationmentioning

confidence: 91%

Innocent Bystander or the Heel of Achilles

Nayyar

Nair

Chauhan

2016

Circ: Arrhythmia and Electrophysiology

View full text Add to dashboard Cite

A 29-year-old male presented with palpitations without a documented tachycardia. ECG showed minimal preexcitation ( Figure 1A), and echo confirmed a normal heart. At electrophysiological study in the drug-free state, the HV interval was 13 ms in sinus rhythm, and ventricular (V) activation in the right paraHisian region preceded the surface delta wave (Figure 2A). Programmed stimulation from the septal right atrium (A) increased preexcitation at shorter S1-S2 intervals (below 600-360 ms), as evidenced by a subtle loss of physiological left-to-right ventricular (RV) septal activation (loss of r wave in V1 and q waves in I, aVL) and an increasingly negative HV interval. The S2-δ interval also prolonged with progressive preexcitation. Figures 1B and 2B show increased preexcitation elicited at an S1-S2 interval of 220 ms. Atrioventricular (AV) effective refractory period was shorter than 600-220 ms, and dual AV nodal physiology was absent. These features along with the existence of escape junctional preexcited beat ( Figure 1C and 2C) supported the presence of a right-sided manifest nodoventricular (NV) pathway bypassing a portion of the AV node, and ruled against typical anterograde AV bypass tracts, Mahaim fibers from AV ring, and fasciculoventricular pathways. See Editor's Perspective by Asirvatham and StevensonRetrograde conduction was through a concealed left lateral accessory pathway (AP) that had slow decremental conduction and a long ventriculoatrial (VA) effective refractory period of 600-340 ms. Despite multiple atrial and ventricular programmed or burst stimulation attempts, no tachycardia was induced. However, coincidental with decrement in retrograde AP conduction (VA interval increasing from 112 to 136 ms), single reciprocating ventricular echo beats were easily reproducible, even during fixed RV pacing at rates moderately faster than the sinus rate (Figure 3). After intravenous adenosine 12-mg, VA block developed during RV pacing (cycle length: 550 ms) consistent with the decremental nature of VA conduction and the lack of typical retrograde bypass tracts ( Figure 1A in the Data Supplement). Soon after recovery of VA block, during ongoing RV pacing, a nonsustained 1:1 VA reciprocating tachycardia (cycle length: 310-345 ms) was induced (lasting 35 s) with an atrial activation pattern identical to that of the ventricular echo beats ( Figure 4A; Figure 1B in the Data Supplement). An His-refractory RV pacing stimulus advanced the subsequent A with resetting of the tachycardia without change in atrial activation ( Figure 4B), thereby confirming participation of the left lateral AP in the tachycardia. The QRS morphology of the ventricular echo beats, the tachycardia and the beat subsequent to the atrial advancement brought by the His-refractory extrastimulus represented variably fused anterograde NV fiber and AV nodal conduction (Figures 3 and 4).In light of these features: (1) Why was the induction and maintenance of tachycardia so difficult, despite easily provoked ventricular echo beats? (2) What was the...

show abstract

Section: Nature Of Anterograde Preexcitationmentioning

confidence: 91%

Innocent Bystander or the Heel of Achilles

Nayyar

Nair

Chauhan

2016

Circ: Arrhythmia and Electrophysiology

View full text Add to dashboard Cite

show abstract

“…1 However, a junctional beat originating proximally may replicate the preexcitation morphology over a nodoventricular pathway as well. 2 Moreover, nonpreexcited junctional beats, as in the presented case, do not exclude the diagnosis of an FVP. This may depend on the electrophysiological properties of the FVP, and the anatomic relation between the junctional focus and the emergence level of this pathway from the specialized HisPurkinje system.…”

mentioning

confidence: 58%

Discordant Junctional Beats and Preexcitation

Ali

Sorgente

Lupo

et al. 2015

Circ: Arrhythmia and Electrophysiology

View full text Add to dashboard Cite

A n 18-year-old woman with Down syndrome and ventricular preexcitation was referred to our center for electrophysiological evaluation. She had no structural heart disease, and her 12-lead ECG showed minimal preexcitation. After obtaining an informed consent, an electrophysiology study was performed under conscious sedation. Via bilateral femoral veins, multipolar diagnostic catheters were introduced and positioned at the His bundle region and coronary sinus. A roving quadripolar catheter was positioned alternatively in the right ventricle, the right atrium appendage, and successively was used for mapping. At the beginning of the procedure, nonpreexcited junctional beats were recorded, a phenomenon compatible with a typical atrioventricular accessory pathway (AP). However, a comprehensive electrophysiology study confirmed the presence of an innocent fasciculoventricular pathway (FVP), showing minimal and fixed preexcitation (ie, the His-ventricular interval) during multisite atrial pacing and at different pacing rates. The effective refractory period of the FVP itself could not be precisely determined during programmed atrial stimulation because block occurred earlier at the atrioventricular node level. Furthermore, incremental atrial pacing showed 1:1 atrioventricular conduction with fixed preexcitation to the point of nodal atrioventricular block at a pacing cycle length of 360 ms. Adenosine administration resulted in prolongation of the P-delta interval without any change in the preexcitation degree. Retrograde conduction was concentric and decremental, and Para-Hisian pacing maneuver showed a nodal pattern. Pure His capture was not feasible during this maneuver, which may have replicated the preexcitation morphology. No tachycardia was inducible with and without isoproterenol infusion. The ventricular insertion of the AP was mapped and localized at the para-Hisian region. No ablation was performed considering the innocent nature of this AP and the noninducibility of any tachycardia.Interestingly, both preexcited and nonpreexcited junctional beats were successively observed ( Figure A). Figure B shows the corresponding intracardiac recordings of a sinus preexcited beat (first beat) followed by 2 junctional beats. The first junctional extrasystole (second beat) reproduced identical preexcitation morphology further confirming the diagnosis of an FVP, whereas the last junctional beat (third beat) showed no preexcitation. This nonpreexcited junctional beat could be explained by a slight shift of the junctional focus to a more distal site (the arrows indicate the earliest His activation) with normalization of the QRS and His-ventricular interval, indicating an early emergence of this FVP from the His bundle ( Figure C). During the electrophysiology study, nonpreexcited junctional beats were not linked to short coupling intervals, making the hypothesis of antegrade AP block at its refractory period unlikely. However, a phase 4 (bradycardia-dependent) block cannot be excluded as a potential mechanism of this phenomen...

show abstract

“…Главным электрофизиологическим отличи-ем трактов Махайма от пучков Кента является декрементный характер проведения по ним, по-добно нормальному атриовентрикулярному сое-динению [8]. В статье представлен клинический случай электрофизиологического исследования у бессимптомного пациента, имеющего атрио-вентрикулярный (АВ) тракт Махайма редкой ло-кализации.…”

Section: фундаментальные аспекты сердечно-сосудистой хирургии Fundameunclassified