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Journal ArticleDOI

Electrophysiological Properties of the Canine Peripheral A-V Conducting System

01 Mar 1970-Circulation Research (Lippincott Williams & Wilkins)-Vol. 26, Iss: 3, pp 361-378
TL;DR: It was demonstrated that appropriately timed premature impulses could be confined within conducting tissue either proximal or distal to the area of maximum action potential duration.
Abstract: Action potential durations and local refractory periods were mapped along the course of canine conducting tissue from bundle branches to the termination of false tendons in ventricular muscle. Standard microelectrode techniques were used. Areas of maximum action potential duration, which coincided with areas of maximum local refractory periods, were consistently found 2 to 3 mm proximal to the termination of conducting fibers in muscle. The refractory periods at the areas of maximum action potential duration were quantitatively identical in the multiple false tendons of a segment of the conducting system, providing a uniform functional limit for the propagation of premature impulses across the distal end of the conducting system of the segments studied. It was demonstrated that appropriately timed premature impulses could be confined within conducting tissue either proximal or distal to the area of maximum action potential duration. This occurred when the area of maximum duration was still refractory, after other areas of the conducting system had recovered excitability. In most preparations, maximum action potential durations and functional refractory periods across distal false tendons were longer in tissue from the right side than from the left side of the conducting system.
Citations
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Journal ArticleDOI
TL;DR: The first initiating beat of ventricular fibrillation had an identical electrocardiographic morphology and coupling interval to preceding isolated premature beats typically noted in the aftermath of resuscitation.
Abstract: Background— Ventricular fibrillation is the main mechanism of sudden cardiac death. The feasibility of eliminating recurrent episodes by catheter ablation has not been reported. Methods and Results— Twenty-seven patients without known heart disease (13 men, 14 women, 41±14 years of age) were studied after being resuscitated from recurrent (10±12) episodes of primary idiopathic ventricular fibrillation; 23 had received a defibrillator. The first initiating beat of ventricular fibrillation had an identical electrocardiographic morphology and coupling interval (297±41 ms) to preceding isolated premature beats typically noted in the aftermath of resuscitation. These triggers were localized by mapping the earliest electrical activity and ablated by local radiofrequency delivery. Outcome was assessed by Holter and defibrillator memory interrogation. Premature beats were elicited from the Purkinje conducting system in 23 patients: from the left ventricular septum in 10, from the anterior right ventricle in 9, an...

568 citations

Journal ArticleDOI
TL;DR: Triggers from the Purkinje arborization or the right ventricular outflow tract have a crucial role in initiating ventricular fibrillation associated with the long-QT and Brugada syndromes and can be eliminated by focal radiofrequency ablation.
Abstract: Background— The long-QT and Brugada syndromes are important substrates of malignant ventricular arrhythmia. The feasibility of mapping and ablation of ventricular arrhythmias in these conditions has not been reported. Methods and Results— Seven patients (4 men; age, 38±7 years; 4 with long-QT and 3 with Brugada syndrome) with episodes of ventricular fibrillation or polymorphic ventricular tachycardia and frequent isolated or repetitive premature beats were studied. These premature beats were observed to trigger ventricular arrhythmias and were localized by mapping the earliest endocardial activity. In 4 patients, premature beats originated from the peripheral right (1 Brugada) or left (3 long-QT) Purkinje conducting system and were associated with variable Purkinje-to-muscle conduction times (30 to 110 ms). In the remaining 3 patients, premature beats originated from the right ventricular outflow tract, being 25 to 40 ms ahead of the QRS. The accuracy of mapping was confirmed by acute elimination of prema...

473 citations

Journal ArticleDOI
TL;DR: The relevance of conduction delay and block in the different regions of the A-V conduction system to the full recovery time and the relative, functional, and effective refractory periods of A-v conduction are indicated.
Abstract: Atrioventricular conduction in the human heart, analyzing electrocardiogram response patterns recorded by electrode catheter in unanesthetized man

348 citations

Journal ArticleDOI
TL;DR: The accuracy of mapping was confirmed by acute elimination of triggers by radiofrequency delivery, and there was no recurrence of ventricular fibrillation in 14 patients, establishing that ablation is curative and avoids use of a defibrillator.

336 citations

References
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Journal ArticleDOI
TL;DR: It was concluded that spontaneous closely coupled beats occurring at slow ventricular rates in A-V dissociation may result from asynchrony in the repolarization of adjacent excitable units.

395 citations

Book
01 Jan 1956

197 citations

Journal ArticleDOI
01 Jan 1954
TL;DR: In this paper, the Herzmuskel noch vom Skeletmnskel durch seine wesentlich größere Empfindlichkeit gegen Sauerstoffmangel.
Abstract: Im Sauerstoffmangel fallen nach einiger Zeit beim l~erv und Skeletmuskel das Ruhennd Aktionslootential ab, die Anstiegsdauer wird l~nger und die Leitungsgeschwindigkeit der Erregung nimmt ab (G~~Al~»S, SI~~~s~0, 31, CowA~3 TI~AIITw~rs et al. 84). Alle diese Ver~nderungen zeigt auch der Herzmnskel, doch ist für ihn charakteristisch die starke Verkürzung und Abflachung der Repolarisation, der Plate~uve rh l s t (Sc~IÜTZ 27, ~-~]~GGLI~ n. NO:B~]~ 11, E ~ K u. SC]3[fl_]~~JEI~6). Weiterhin unterscheidet sich der Herzmuskel noch vom Skeletmnskel durch seine wesentlich größere Empfindlichkeit gegen Sauerstoffmangel. Diese Ergebnisse wurden am Warmblüterherzen in sitn gewonnen, der Sauerstoffmangel durch Abstellen der Atempumpe oder durch Stickstoffbeatmung erreicht und der Al~ionsstrom nach dem Prinzip des ScHÜTZschen Herzwandknotens (in den Versuchen von EI~K u. SCI~AEI~EI¢ mit einer Mikrosogelektrode) monophasisch abgeleitet. Die genaueren Bedingungen sowohl in bezug auf den Grad des Sauerstoffmangels als auch die quantitative Erfassnng der PoLentialveränderun6en sind mit diesen ~e*hoden nicht unbedingt definiert, obwohl sie recht gut geeignet sind, den Plateauverlust zu messen. Unsere Arbeit will nun mit der l~ethode der in*racellulgren Ableitung in vitro bei genau bekannter Sanerstoffkonzentration die Entwicklung des Plateauverlustes untersuchen und diesen in Beziehung zu Änderungen der Potentialhöhen, der Anstiegsdauer und Leitnngsgeschwindigkeit setzen. Bisher wurde am Myokard des Warmblüters in vitro mit der Capillarelektrode hanptsgchlich am P~mKnVJE~&den (Dl%2*~I'El% u. W~II)lVI2klqlf 5, ~I~I%AUTWEIIf u. ZIIqK 33, TRAUTWErN el a1.85), dazu am Vorhof der Katze (BlraG~~ u. TEl~l~OVX 1, 2) und am Papillarmuskel der Katze (I-Iol~l~~I~lv u. SvoxLI~G 14) gearbeitet. Besonders bietet sich der Pul~KI~lJE-l~aden wegen seiner l~einheit, seiner geringen mechanischen Bewegungen, und seiner großen Resistenz gegenüber Sauerstoffmangel als geeignetes Prgparat an. Eine Untersuchung

170 citations