The estimation of sinoatrial conduction time in rabbit heart by the constant atrial pacing technique.

Published

Journal Article

This study compared estimates of sinoatrial conduction time (SACT) obtained by constant atrial pacing (CAP) and premature atrial stimulation (PAS) with measured SACT in isolated rabbit right atrial preparations. Transmembrane potentials and surface electrograms were recorded from the sinus node and crista terminalis, respectively. The crista terminalis was paced 5, 10 and 15 beats/min faster than the spontaneous sinus rate with a train of eight pulses. Estimate of SACT by CAP was taken as the difference between the first atrial return cycle and the mean spontaneous cycle length. SACTs at 5, 10 and 15 beats/min faster were 76 +/- 10, 86 +/- 10 and 96 +/- 10 msec (mean +/- SEM; n = 12), respectively; correlation coefficients with the true SACT were 0.7, 0.54 and 0.4. Consecutive determinations of SACT by PAS and CAP in the same preparation (n = 6) at 10 beats/min faster gave SACTs of 86 +/- 13 and 79 +/- 14 msec, respectively, compared with true SACTs of 79 +/- 10 msec. Shortening of sinus node action potential, depression of automaticity and shifts in the site of the primary pacemaker contributed to the errors in both techniques. Estimation of SACT by CAP may be further complicated by failure of sinus node capture. Principles to minimize some of these errors are also presented.

Full Text

Duke Authors

Cited Authors

  • Grant, AO; Kirkorian, G; Benditt, DG; Strauss, HC

Published Date

  • September 1, 1979

Published In

Volume / Issue

  • 60 / 3

Start / End Page

  • 597 - 604

PubMed ID

  • 455623

Pubmed Central ID

  • 455623

International Standard Serial Number (ISSN)

  • 0009-7322

Digital Object Identifier (DOI)

  • 10.1161/01.cir.60.3.597

Language

  • eng

Conference Location

  • United States