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

Abstract

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
Teens
Cardiac Conduction System
Structure of Atrioventricular Node
Bundle of His
Entire Atrioventricular Node

Related Feeds

Atrial Fibrillation

Atrial fibrillation is a common arrhythmia that is associated with substantial morbidity and mortality, particularly due to stroke and thromboembolism. Here is the latest research.

Arrhythmia

Arrhythmias are abnormalities in heart rhythms, which can be either too fast or too slow. They can result from abnormalities of the initiation of an impulse or impulse conduction or a combination of both. Here is the latest research on arrhythmias.

Cardiac Conduction System

The cardiac conduction system is a specialized tract of myocardial cells responsible for maintaining normal cardiac rhythm. Discover the latest research on the cardiac conduction system here.

Cardiovascular Diseases: Risk Factors

Cardiovascular disease is a significant health concern. Risk factors include hypertension, obesity, dyslipidemia and smoking. Women who are postmenopausal are at an increased risk of heart disease. Here is the latest research for risk factors of cardiovascular disease.