title: Exercise-induced improvement in atrial depolarization abnormality in a patient after treatment with beta-adrenergic blockers.
abstract: Abnormal atrial depolarization, characterized by P waves >or=110 ms on the electrocardiogram, can manifest as partial or advanced interatrial conduction delay or interatrial block (IAB). Progression from partial to advanced IAB has been shown to be altered by the use of angiotensin-converting enzyme inhibitors and beta-adrenergic blockers. We previously reported that advanced IAB, denoted by biphasic P waves in leads II, II and aVF, can revert intermittently to its partial counterpart. However, potential factors that could induce such resolution remain unknown. We present the first known case of resolution of advanced IAB to partial IAB occurring during graded exercise, following treatment with a beta-adrenergic blocker. Only continued study of these and other novel factors will help us understand the exact pathophysiology of both, partial and advanced IAB.
authors.affiliation: Division of Cardiology, Department of Medicine, St. Boniface General Hospital/University of Manitoba, Winnipeg, Manitoba, Canada. vignendra@hotmail.com
authors.forename: Vignendra
authors.initials: V
authors.lastname: Ariyarajah
authors.forename: Nasir
authors.initials: N
authors.lastname: Shaikh
authors.forename: David H
authors.initials: DH
authors.lastname: Spodick
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000368:Aged; D004562:Electrocardiography; D015444:Exercise; D006327:Heart Block / Q000188:drug therapy*; D006801:Humans; D008297:Male
chemical_list: D000319:Adrenergic beta-Antagonists