Scaling of Atrioventricular Transmission in Mammalian Species: An Evolutionary Riddle

Scaling of AV Transmission.“Scaling deals with the structural and functional consequences of changes in size or scale among otherwise similar organisms.” It plays a key role in all studies on comparative mammalian physiology and morphology. Heart weight is proportionally related to body weight and c...

Full description

Saved in:
Bibliographic Details
Published in:Journal of cardiovascular electrophysiology 2002-08, Vol.13 (8), p.826-830
Main Authors: MEIJLER, FRITS L., STRACKEE, JAN, STOKHOF, ARNOLD A., WASSENAAR, CLAES
Format: Article
Language:English
Subjects:
Age Factors
Animals
Animals, Newborn - physiology
Atrioventricular Node - physiology
Biomedical Engineering
Body Composition - physiology
Body Constitution - physiology
Body Weight - physiology
comparative atrioventricular transmission
Electrocardiography
evolution
Heart - anatomy & histology
mammalian heart
Mammals - anatomy & histology
Models, Animal
Models, Cardiovascular
Organ Size - physiology
Physiology, Comparative
scaling
Signal Transduction - physiology
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Scaling of AV Transmission.“Scaling deals with the structural and functional consequences of changes in size or scale among otherwise similar organisms.” It plays a key role in all studies on comparative mammalian physiology and morphology. Heart weight is proportionally related to body weight and can be described by a straightforward, so‐called allometric equation. We studied scaling of AV transmission times (PR intervals on the ECG) in 375 mammals of different dimensions and species. Scaling of AV transmission times versus heart length (third root of weight) is statistically best described by a S‐shaped curve. This implies that AV transmission time in mammals is not linearly related to heart length and does not depend solely on the length of the AV transmission system. The AV node fine‐tunes AV transmission times at rest and during exercise in individuals; it protects the ventricles against high‐rate atrial arrhythmias such as atrial fibrillation; and it regulates basal AV transmission times in mammalian species of varying sizes. We call the “how” and “why” of the scaling of AV transmission time in mammals an evolutionary riddle that deserves further study.
ISSN:1045-3873
1540-8167
DOI:10.1046/j.1540-8167.2002.00826.x