{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,29]],"date-time":"2026-04-29T04:09:07Z","timestamp":1777435747725,"version":"3.51.4"},"reference-count":0,"publisher":"Ovid Technologies (Wolters Kluwer Health)","issue":"5","content-domain":{"domain":["www.ahajournals.org"],"crossmark-restriction":true},"short-container-title":["Circulation"],"published-print":{"date-parts":[[1975,11]]},"abstract":"<jats:p>In patients with atrioventricular (A-V) nodal re-entrant paroxysmal supraventricular tachycardia (PSVT), atrial extrastimulus technique frequently reveals discontinuous A1-A2, H1-H2 curves suggestive of dual A-V nodal pathways. To further test the hypothesis that these curves in fact reflect dual A-V nodal pathways, a ventricular extrastimulus (VS) was coupled either to A2 at a fixed A1-A2 interval which reliably produced an A-V nodal re-entrant atrial echo (E) with a constant A2-E interval in two patients, or to QRS complex (V) during sustained PSVT with a constant E-E interval in one patient. Three response zones were defined: at longer A2-VS or V-VS coupling interval, VS manifested no effect on the timing of E (Zone 1). At closer A2-VS or V-VS coupling interval, VS conducted to the atrium, shortening the apparent A2-E or E-E interval (Zone 2). At shortest A2-VS or V-VS coupling interval, VS was blocked retrogradely, and no E was induced (Zone 3). The ability of VS to preempt control of the atria (Zone 2 response) strongly suggests the presence of dual A-V nodal pathways in these PSVT patients. If only a single pathway were present, VS would of necessity collide with the antegrade impulse and could not reach the atria. The Zone 3 response occurs because of retrograde refractoriness of the fast pathway. Failure of the echo during Zone 3 probably reflects concealed conduction to the fast pathway, or possibly interference in the slow pathway.<\/jats:p>","DOI":"10.1161\/01.cir.52.5.789","type":"journal-article","created":{"date-parts":[[2012,6,11]],"date-time":"2012-06-11T23:57:40Z","timestamp":1339459060000},"page":"789-798","update-policy":"https:\/\/doi.org\/10.1161\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":55,"title":["Demonstration of dual atrioventricular nodal pathways utilizing a ventricular extrastimulus in patients with atrioventricular nodal re-entrant paroxysmal supraventricular tachycardia."],"prefix":"10.1161","volume":"52","author":[{"given":"D","family":"Wu","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"P","family":"Denes","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"C","family":"Wyndham","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"F","family":"Amat-y-Leon","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"R C","family":"Dhingra","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"K M","family":"Rosen","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"276","container-title":["Circulation"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.ahajournals.org\/doi\/pdf\/10.1161\/01.CIR.52.5.789","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,5,12]],"date-time":"2024-05-12T13:55:19Z","timestamp":1715522119000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.ahajournals.org\/doi\/10.1161\/01.CIR.52.5.789"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1975,11]]},"references-count":0,"journal-issue":{"issue":"5","published-print":{"date-parts":[[1975,11]]}},"alternative-id":["10.1161\/01.CIR.52.5.789"],"URL":"https:\/\/doi.org\/10.1161\/01.cir.52.5.789","relation":{},"ISSN":["0009-7322","1524-4539"],"issn-type":[{"value":"0009-7322","type":"print"},{"value":"1524-4539","type":"electronic"}],"subject":[],"published":{"date-parts":[[1975,11]]},"assertion":[{"value":"1975-11-01","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}