Overdrive suppression of conduction at the canine Purkinje-muscle junction

R. F. Gilmour, J. R. Davis, D. P. Zipes

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

We have shown previously that overdrive suppression of conduction in depolarized His-Purkinje tissue requires conduction asymmetry. In this study we examined whether overdrive suppression of conduction can occur at the Purkinje-muscle junction, where natural asymmetry of conduction exists. Canine Purkinje-muscle preparations were superfused with hyperkalemic Tyrode's solution (KCl 8 to 12 mM), and action potentials were recorded from Purkinje, junctional, and muscle cells. Initially, the Purkinje fiber was paced at the shortest cycle length at which 1:1 anterograde Purkinje-muscle conduction occurred. The papillary muscle then was paced for 10 to 50 beats at shorter cycle lengths during which, because of conduction asymmetry at the Purkinje-muscle junction, 1:1 retrograde muscle-Purkinje conduction also occurred. After overdrive papillary muscle pacing, Purkinje fiber pacing at the same cycle length that previously resulted in 1:1 conduction now produced transient Purkinje-muscle conduction block (overdrive suppression of conduction). The degree and duration of overdrive suppression of conduction were proportional to the rate and duration of overdrive pacing. After overdrive pacing, Purkinje cell action potential amplitude and V̇max recovered within 300 msec, yet conduction block persisted for up to 7 sec. In contrast, excitability in papilary muscle cells near the Purkinje-muscle junction increased continuously after overdrive pacing. These data suggest that rapid activation of Purkinje cells during overdrive pacing was not required for overdrive suppression of conduction and that restoration of conduction after overdrive pacing was determined primarily by recovery of excitability in papillary muscle cells. Transient Purkinje-muscle conduction block after periods of rapid ventricular rates might account for overdrive-induced conduction disturbances normally attributed to bundle branch block.

Original languageEnglish (US)
Pages (from-to)1388-1396
Number of pages9
JournalCirculation
Volume76
Issue number6
DOIs
StatePublished - Jan 1 1987

Fingerprint

Canidae
Muscles
Papillary Muscles
Purkinje Cells
Muscle Cells
Purkinje Fibers
Action Potentials
Bundle-Branch Block

ASJC Scopus subject areas

  • Physiology
  • Cardiology and Cardiovascular Medicine

Cite this

Overdrive suppression of conduction at the canine Purkinje-muscle junction. / Gilmour, R. F.; Davis, J. R.; Zipes, D. P.

In: Circulation, Vol. 76, No. 6, 01.01.1987, p. 1388-1396.

Research output: Contribution to journalArticle

Gilmour, R. F. ; Davis, J. R. ; Zipes, D. P. / Overdrive suppression of conduction at the canine Purkinje-muscle junction. In: Circulation. 1987 ; Vol. 76, No. 6. pp. 1388-1396.
@article{cecb256174bf482481c68dadbe943775,
title = "Overdrive suppression of conduction at the canine Purkinje-muscle junction",
abstract = "We have shown previously that overdrive suppression of conduction in depolarized His-Purkinje tissue requires conduction asymmetry. In this study we examined whether overdrive suppression of conduction can occur at the Purkinje-muscle junction, where natural asymmetry of conduction exists. Canine Purkinje-muscle preparations were superfused with hyperkalemic Tyrode's solution (KCl 8 to 12 mM), and action potentials were recorded from Purkinje, junctional, and muscle cells. Initially, the Purkinje fiber was paced at the shortest cycle length at which 1:1 anterograde Purkinje-muscle conduction occurred. The papillary muscle then was paced for 10 to 50 beats at shorter cycle lengths during which, because of conduction asymmetry at the Purkinje-muscle junction, 1:1 retrograde muscle-Purkinje conduction also occurred. After overdrive papillary muscle pacing, Purkinje fiber pacing at the same cycle length that previously resulted in 1:1 conduction now produced transient Purkinje-muscle conduction block (overdrive suppression of conduction). The degree and duration of overdrive suppression of conduction were proportional to the rate and duration of overdrive pacing. After overdrive pacing, Purkinje cell action potential amplitude and V̇max recovered within 300 msec, yet conduction block persisted for up to 7 sec. In contrast, excitability in papilary muscle cells near the Purkinje-muscle junction increased continuously after overdrive pacing. These data suggest that rapid activation of Purkinje cells during overdrive pacing was not required for overdrive suppression of conduction and that restoration of conduction after overdrive pacing was determined primarily by recovery of excitability in papillary muscle cells. Transient Purkinje-muscle conduction block after periods of rapid ventricular rates might account for overdrive-induced conduction disturbances normally attributed to bundle branch block.",
author = "Gilmour, {R. F.} and Davis, {J. R.} and Zipes, {D. P.}",
year = "1987",
month = "1",
day = "1",
doi = "10.1161/01.CIR.76.6.1388",
language = "English (US)",
volume = "76",
pages = "1388--1396",
journal = "Circulation",
issn = "0009-7322",
publisher = "Lippincott Williams and Wilkins",
number = "6",

}

TY - JOUR

T1 - Overdrive suppression of conduction at the canine Purkinje-muscle junction

AU - Gilmour, R. F.

AU - Davis, J. R.

AU - Zipes, D. P.

PY - 1987/1/1

Y1 - 1987/1/1

N2 - We have shown previously that overdrive suppression of conduction in depolarized His-Purkinje tissue requires conduction asymmetry. In this study we examined whether overdrive suppression of conduction can occur at the Purkinje-muscle junction, where natural asymmetry of conduction exists. Canine Purkinje-muscle preparations were superfused with hyperkalemic Tyrode's solution (KCl 8 to 12 mM), and action potentials were recorded from Purkinje, junctional, and muscle cells. Initially, the Purkinje fiber was paced at the shortest cycle length at which 1:1 anterograde Purkinje-muscle conduction occurred. The papillary muscle then was paced for 10 to 50 beats at shorter cycle lengths during which, because of conduction asymmetry at the Purkinje-muscle junction, 1:1 retrograde muscle-Purkinje conduction also occurred. After overdrive papillary muscle pacing, Purkinje fiber pacing at the same cycle length that previously resulted in 1:1 conduction now produced transient Purkinje-muscle conduction block (overdrive suppression of conduction). The degree and duration of overdrive suppression of conduction were proportional to the rate and duration of overdrive pacing. After overdrive pacing, Purkinje cell action potential amplitude and V̇max recovered within 300 msec, yet conduction block persisted for up to 7 sec. In contrast, excitability in papilary muscle cells near the Purkinje-muscle junction increased continuously after overdrive pacing. These data suggest that rapid activation of Purkinje cells during overdrive pacing was not required for overdrive suppression of conduction and that restoration of conduction after overdrive pacing was determined primarily by recovery of excitability in papillary muscle cells. Transient Purkinje-muscle conduction block after periods of rapid ventricular rates might account for overdrive-induced conduction disturbances normally attributed to bundle branch block.

AB - We have shown previously that overdrive suppression of conduction in depolarized His-Purkinje tissue requires conduction asymmetry. In this study we examined whether overdrive suppression of conduction can occur at the Purkinje-muscle junction, where natural asymmetry of conduction exists. Canine Purkinje-muscle preparations were superfused with hyperkalemic Tyrode's solution (KCl 8 to 12 mM), and action potentials were recorded from Purkinje, junctional, and muscle cells. Initially, the Purkinje fiber was paced at the shortest cycle length at which 1:1 anterograde Purkinje-muscle conduction occurred. The papillary muscle then was paced for 10 to 50 beats at shorter cycle lengths during which, because of conduction asymmetry at the Purkinje-muscle junction, 1:1 retrograde muscle-Purkinje conduction also occurred. After overdrive papillary muscle pacing, Purkinje fiber pacing at the same cycle length that previously resulted in 1:1 conduction now produced transient Purkinje-muscle conduction block (overdrive suppression of conduction). The degree and duration of overdrive suppression of conduction were proportional to the rate and duration of overdrive pacing. After overdrive pacing, Purkinje cell action potential amplitude and V̇max recovered within 300 msec, yet conduction block persisted for up to 7 sec. In contrast, excitability in papilary muscle cells near the Purkinje-muscle junction increased continuously after overdrive pacing. These data suggest that rapid activation of Purkinje cells during overdrive pacing was not required for overdrive suppression of conduction and that restoration of conduction after overdrive pacing was determined primarily by recovery of excitability in papillary muscle cells. Transient Purkinje-muscle conduction block after periods of rapid ventricular rates might account for overdrive-induced conduction disturbances normally attributed to bundle branch block.

UR - http://www.scopus.com/inward/record.url?scp=0023473550&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0023473550&partnerID=8YFLogxK

U2 - 10.1161/01.CIR.76.6.1388

DO - 10.1161/01.CIR.76.6.1388

M3 - Article

C2 - 3677361

AN - SCOPUS:0023473550

VL - 76

SP - 1388

EP - 1396

JO - Circulation

JF - Circulation

SN - 0009-7322

IS - 6

ER -