Some observations on the mechanism of pressure related atrial fibrillation
Φόρτωση...
Ημερομηνία
Τίτλος Εφημερίδας
Περιοδικό ISSN
Τίτλος τόμου
Εκδότης
Περίληψη
Τύπος
Είδος δημοσίευσης σε συνέδριο
Είδος περιοδικού
peer-reviewed
Είδος εκπαιδευτικού υλικού
Όνομα συνεδρίου
Όνομα περιοδικού
Eur Heart J
Όνομα βιβλίου
Σειρά βιβλίου
Έκδοση βιβλίου
Συμπληρωματικός/δευτερεύων τίτλος
Περιγραφή
In order to investigate the effect of atrial pressure on the propensity of the atria to fibrillate and the mechanism of this association, the right atrial pressure was changed acutely by transfusion-bleeding in 12 anaesthetized open-chest dogs. Under various atrial pressures the conduction time was measured between two pairs of hook electrodes positioned on the two atrial appendages respectively. The effective refractory period was measured by continuous pacing of the right atrium at a 250 ms cycle length at double threshold intensity and interpolating a progressively earlier stimulus after each eighth paced beat. The propensity of fibrillation was studied by rapid (450 min-1) pacing of the atria at double threshold intensity for 10 s at different atrial pressures. At a high (> or = 14 mmHg) atrial pressure the conduction time (45.7 +/- 14.2 ms) was significantly (P < 0.01) longer, the effective refractory period (157.9 +/- 15.2 ms) significantly (P < 0.01) longer and the atrial fibrillation (11/19 or 57.9%) significantly (chi 2 = 9.95, P < 0.001) more common than at a low (< or = 10 mmHg) pressure (35.2 +/- 11.6, 146.2 +/- 12.4, 3/24 or 12.5%, respectively). Analysis of variance showed that the probability of atrial fibrillation was significantly affected by the atrial pressure but not by either the conduction time or the effective refractory period. The findings suggest that an increase in right atrial pressure by acute volume overload prolongs the inter-atrial conduction time and right atrial refractoriness and increases the propensity of the atria to fibrillate by rapid atrial stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)
Περιγραφή
Λέξεις-κλειδιά
Analysis of Variance, Animals, Atrial Fibrillation/*etiology, Atrial Function, Atrial Function, Right/*physiology, Cardiac Volume, Dogs, Heart Conduction System/physiology, Pressure
Θεματική κατηγορία
Παραπομπή
Σύνδεσμος
http://www.ncbi.nlm.nih.gov/pubmed/7835375
Γλώσσα
en
Εκδίδον τμήμα/τομέας
Όνομα επιβλέποντος
Εξεταστική επιτροπή
Γενική Περιγραφή / Σχόλια
Ίδρυμα και Σχολή/Τμήμα του υποβάλλοντος
Πανεπιστήμιο Ιωαννίνων. Σχολή Επιστημών Υγείας. Τμήμα Ιατρικής