Alternative mechanisms of apparent supernormal atrioventricular conduction
| Autor: | Anthony N. Damato, Sun H. Lau, Mark E. Josephson, John J. Gallagher, P.Jacob Varghese, Anthony R. Caracta |
|---|---|
| Rok vydání: | 1973 |
| Předmět: |
Cardiac Catheterization
medicine.medical_specialty Refractory period Bundle-Branch Block Electrocardiography Heart Conduction System Internal medicine Bradycardia medicine Humans cardiovascular diseases Bundle branch block business.industry Atrioventricular conduction Arrhythmias Cardiac Depolarization Reentry medicine.disease Bundle branches Heart Block medicine.anatomical_structure Ventricle Anesthesia cardiovascular system Cardiology Wenckebach phenomenon Cardiology and Cardiovascular Medicine business |
| Zdroj: | The American Journal of Cardiology. 31:362-371 |
| ISSN: | 0002-9149 |
| DOI: | 10.1016/0002-9149(73)90269-5 |
| Popis: | Alternative mechanisms were found to explain several different electrocardiographic examples of apparent supernormal atrioventricular (A-V) conduction in man using programmed premature atrial and ventricular stimulation and His bundle recordings. Sudden shortening of the P-R interval during A-V nodal Wenckebach phenomenon was due to manifest or concealed reentry within the A-V node. Gap phenomena in which late atrial premature depolarizations blocked while earlier atrial premature depolarizations conducted were shown to result from delay of earlier atrial premature depolarizations in the A-V node (type I gap) or in the His-Purkinje system (type II gap). Mechanisms analogous to the latter were found in cases of apparent supernormality of intraventricular conduction: Late atrial premature depolarizations resulted in aberration whereas earlier atrial premature depolarizations conducted normally because of delay within the A-V node or His-Purkinje system. Unexpected normalization of a bundle branch block pattern also resulted from Wenckebach phenomenon in the bundle branches. Atypical Wenckebach phenomenon with the first beat of the period demonstrated that aberration was due to phase 4 depolarization. Preexcitation of the ventricle before the delivery of a previously blocked atrial premature depolarization allowed conduction through the area of block (A-V node) because of earlier depolarization of the latter with earlier recovery. In the His-Purkinje system, 2:1 A-V block was converted to 1:1 conduction when a premature ventricular depolarization shortened the refractoriness of the His-Purkinje system. |
| Databáze: | OpenAIRE |
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