Tachycardia- and bradycardia-dependent atrioventricular block: Observations regarding the mechanism of block

P. Denes*, I. Murabit, M. Ezri, C. Eybel

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

6 Scopus citations

Abstract

A case of paroxysmal bradycardia- and tachycardia-dependent atrioventricular (AV) block is described in a patient with right bundle branch block. The His bundle recordings demonstrated the site of the AV block to be distal to the His bundle recording site (probably in the left bundle branch). Whereas AV block distal to the His bundle occurred at an atrial paced cycle length of 700 ms, intact ventriculoatrial (VA) conduction was present up to a ventricular paced cycle length of 400 ms. Resumption of AV conduction was dependent on a critical HH or RH (in case of escapes) interval. These findings suggest that the bradycardia-dependent block is related to a time-dependent decrease in the amplitude of the current intensity of the proximal segment during late diastole. Spontaneous diastolic depolarization during late diastole resulted in impaired anterograde (AV) conduction but facilitated retrograde (VA) conduction. These findings are consistent with experimental “in vitro” observation in the sucrose gap model of AV block.

Original languageEnglish (US)
Pages (from-to)446-449
Number of pages4
JournalJournal of the American College of Cardiology
Volume9
Issue number2
DOIs
StatePublished - 1987

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine

Fingerprint Dive into the research topics of 'Tachycardia- and bradycardia-dependent atrioventricular block: Observations regarding the mechanism of block'. Together they form a unique fingerprint.

Cite this