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Prevalence and significance of Exit Block During Arrhythmias Arising in Pulmonary Veins
Author(s) -
TSE HUNGFAT,
LAU CHUPAK,
KOU WILLIAM,
PELOSI FRANK,
ORAL HAKAN,
KIM MICHAEL,
F GREGORY,
P BRADLEY,
MOSCUCCI MAURO,
STRICKBERGER S. ADAM,
MORADY FRED
Publication year - 2000
Publication title -
journal of cardiovascular electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.193
H-Index - 138
eISSN - 1540-8167
pISSN - 1045-3873
DOI - 10.1111/j.1540-8167.2000.tb00332.x
Subject(s) - medicine , pulmonary vein , cardiology , tachycardia , catheter ablation , ablation , atrial tachycardia , atrial fibrillation , vein , radiofrequency ablation , left pulmonary vein , anesthesia
Exit Block. Introduction: Recent studies described the occurrence of conduction block within pulmonary veins. The purpose of this study was to evaluate the prevalence of exit block during arrhythmias that arise in pulmonary veins. Methods and Results : Twenty‐five patients with atrial tachycardia/fibrillation underwent successful ablation of 28 arrhythmogenic foci within a pulmonary vein. The prevalence of exit block in the pulmonary veins was determined in 28 arrhythmogenic pulmonary veins and 40 nonarrhythmogenic pulmonary veins. During isolated premature depolarizations, exit block in a pulmonary vein was observed at 50% of arrhythmogenic pulmonary vein sites and was never observed within pulmonary veins that did not generate a tachycardia (P < 0.01). During tachycardia, exit block from a pulmonary vein was observed in 61% of the arrhythmogenic pulmonary veins. The mean cycle length of the pulmonary vein tachycardias associated with exit block was significantly shorter than the cycle length of tachycardia that were not associated with exit block (163 ± 32 vs 251 ± 45 msec, P < 0.001), Exit block in two pulmonary veins during the same episode of tachycardia was observed in 3 of the 28 arrhythmogenic pulmonary veins (11%) in three different patients. Simultaneous recordings in the two pulmonary veins demonstrated bursts of tachycardia in both veins that were not synchronized. Radiofrequency catheter ablation of the arrhythmogenic site in one of the pulmonary veins eliminated spontaneous recurrences of tachycardia from the other pulmonary vein. Conclusion: Exit block from pulmonary veins is a common observation during tachycardias generated within pulmonary veins and indicates that an arrhythmogenic pulmonary vein has been identified. The occurrence of exit block in more than one pulmonary vein most likely is attributable to simultaneous tachycardias, one or both of which may be tachycardia induced and perpetuated by the other.