Jan 1, 1986

Application of the Rosenblueth hypothesis to assess cycle length effects on the refractoriness of the atrioventricular node

The American Journal of Cardiology
M L YoungH Gelband


In adults, the effective refractory period of the atrioventricular (AV) node is lengthened, whereas that of the atrium, His-Purkinje system or ventricular myocardium is shortened with a shorter atrial pacing cycle length. However, in children, the effective refractory period of the AV node at shorter cycle lengths is also shortened. Based on Rosenblueth's 1-step delay hypothesis, an index of refractoriness within the AV node is defined as the longest coupling interval at the level of step delay within the AV node of an impulse that cannot be conducted to the His bundle. The slopes relating cycle length and refractoriness of the AV node are determined by both the conventional and revised methods in 9 pediatric patients with heart disease. The slope is positive for all patients using the revised method. The difference in values between the 2 methods in older children is striking because the slope is converted from a negative to a positive value. It is concluded that the AV node has the same positive slope relating cycle length and refractoriness as other cardiac tissues.

Mentioned in this Paper

Isolated Noncompaction of the Ventricular Myocardium
Refractory Period, Electrophysiological
Right Atrial Structure
Nerve Conduction Function
Refractory Period
Cardiac Conduction System
Structure of Atrioventricular Node
Bundle of His
Entire Atrioventricular Node

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