Modulation of conduction and refractoriness in atrioventricular junctional reentrant circuit. Effect on reentry initiated by atrial extrastimulus
| Autor: | P. J. Tchou, Masood Akhtar, Mohammad Jazayeri, Rehan Mahmud, S Denker |
|---|---|
| Rok vydání: | 1988 |
| Předmět: |
Adult
Male Tachycardia medicine.medical_specialty Refractory period Tachycardia Sinoatrial Nodal Reentry Heart Conduction System Internal medicine Tachycardia Supraventricular medicine Humans Heart Atria Atrium (architecture) business.industry Cardiac Pacing Artificial General Medicine Reentry Middle Aged Atrioventricular node Electric Stimulation Electrophysiology Reentrancy medicine.anatomical_structure Atrioventricular Node cardiovascular system Cardiology Female Wolff-Parkinson-White Syndrome Electrical conduction system of the heart medicine.symptom business Research Article |
| Zdroj: | Journal of Clinical Investigation. 81:39-46 |
| ISSN: | 0021-9738 |
| Popis: | The importance of activation sequence of an atrioventricular junctional reentrant (AVJRe) circuit, before delivery of an extrastimulus, has received little attention in studies concerned with clinical tachycardias. In this study a change in activation sequence was accomplished using bidirectional activation (V-A sequential pacing) during the basic drive (V1A1-V1A1). It was noted that, compared with an atrial extrastimulus (A2) after an atrial drive (A1-A1), earlier activation (by V1 impulse of the V1A1-V1A1 drive) consistently improved conduction, or decreased refractoriness, or both, in the anterograde as well as the retrograde pathway of the AVJRe circuit. In all patients, five with AV nodal reentry and six with Wolff-Parkinson-White syndrome, reentrant tachycardia could be prevented during V-A sequential pacing. In four of eleven patients, reentry was prevented despite achieving the so-called critical atrioventricular nodal delays that had previously caused reentry during control study. This finding suggested that conduction delay necessary for reentry was related to the site of block, which in turn was affected by V-A sequential pacing. We concluded that changing the activation sequence during basic drive modulates conduction and refractoriness in AVJRe circuits, and allows the study of a wide range of electrophysical factors that prevent or permit reentry. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|