Atrioventricular nodal function in the immature canine heart

J. McCormack, H. Gelband, H. Xu, J. Villafane, A. Stolfi, A. S. Pickoff

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

Previous studies have suggested that the atrioventricular nodal functional refractory period in the neonate is equal to or shorter than that of the ventricle, providing little or no protection to the ventricle against rapid atrial rates and allowing closely coupled atrial beats to fall within the ventricular vulnerable period. We evaluated atrioventricular node function in 21 mongrel neonatal puppies, 3-15 days old, and 15 adult dogs utilizing intracardiac His bundle recording and stimulation techniques. The mean atrioventricular nodal functional refractory period (173.1 ± 20.0 ms) exceeded both the ventricular effective refractory period (139.5 ± 14.3) and ventricular functional refractory period (163.3 ± 14.5) in the neonates. Furthermore, the atrioventricular node was the site of limiting antegrade conduction in all neonates. No ventricular arrhythmias were induced by atrial extrastimulation in any of the neonates. The site of conduction delay during atrial extrastimulation was confined to the atrioventricular node in 15/16 neonates (94%) while 1/16 (6%) had combined nodal and infranodal delay. The neonates developed Wenckebach, at significantly faster heart rates than the adults, but both groups developed Wenckebach at approximately twice the resting heart rate. Retrograde conduction was a consistent finding in the neonates. However, antegrade Wenckebach occurred at a significantly faster heart rate than retrograde Wenckebach suggesting different functional properties. Our data suggest than in the neonatal canine, the atrioventricular node functional refractory period is longer than both the ventricular effective refractory period and ventricular functional refractory period. Furthermore, the degree of protection offered by the neonatal atrioventricular node to the ventricle appears to be comparable to that of the adult.

Original languageEnglish
Pages (from-to)99-103
Number of pages5
JournalPediatric Research
Volume23
Issue number1
StatePublished - Jan 1 1988
Externally publishedYes

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Atrioventricular Node
Canidae
Heart Rate
Bundle of His
Cardiac Arrhythmias
Dogs

ASJC Scopus subject areas

  • Pediatrics, Perinatology, and Child Health

Cite this

McCormack, J., Gelband, H., Xu, H., Villafane, J., Stolfi, A., & Pickoff, A. S. (1988). Atrioventricular nodal function in the immature canine heart. Pediatric Research, 23(1), 99-103.

Atrioventricular nodal function in the immature canine heart. / McCormack, J.; Gelband, H.; Xu, H.; Villafane, J.; Stolfi, A.; Pickoff, A. S.

In: Pediatric Research, Vol. 23, No. 1, 01.01.1988, p. 99-103.

Research output: Contribution to journalArticle

McCormack, J, Gelband, H, Xu, H, Villafane, J, Stolfi, A & Pickoff, AS 1988, 'Atrioventricular nodal function in the immature canine heart', Pediatric Research, vol. 23, no. 1, pp. 99-103.
McCormack J, Gelband H, Xu H, Villafane J, Stolfi A, Pickoff AS. Atrioventricular nodal function in the immature canine heart. Pediatric Research. 1988 Jan 1;23(1):99-103.
McCormack, J. ; Gelband, H. ; Xu, H. ; Villafane, J. ; Stolfi, A. ; Pickoff, A. S. / Atrioventricular nodal function in the immature canine heart. In: Pediatric Research. 1988 ; Vol. 23, No. 1. pp. 99-103.
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