title: Atrial premature beats in patients with focal atrial fibrillation: incidence at baseline and impact of provocative maneuvers.
abstract: This study evaluated the incidence of atrial premature beats (APBs) and the impact of various provocative maneuvers in patients with focally initiated AF. Fifty patients (39 men, 57 +/- 0.4 years) with focally initiated, paroxysmal AF underwent Holter recording and a standardized protocol of provocative maneuvers: vagomechanical stimulation, adenosine 12 mg i.v., esmolol 500 ng/kg i.v., orciprenaline i.v. 5 mg/50 mL saline 0.9%, and atropine 0.01 mg/kg i.v. A surface ECG was recorded for 20 minutes at baseline and following each part of the protocol. High focal activity was defined as > or = 1 APB/minute. During Holter ECG, 29 (58%) patients had an amount of < 200 APBs, 12 (24%) patients < 700 > or = 200, and 9 (18%) patients > or = 700 APBs. Less than 1 hour of high focal activity was observed in 34 (68%) of the 50 patients. Before starting provocative maneuvers 15 (30%) patients had high focal activity whereas 35 (70%) presented < 1 APB/minute. In 29 (58%) patients APBs increased by > or = 1/min during provocative maneuvers: by vagomechanical stimulation in 11 patients, after adenosine in 15, esmolol in 12, orciprenaline in 15, and after atropine in 9 patients. In all patients with > or = 1 APB/min at baseline, focal activity decreased or disappeared during some single provocative maneuvers. AF occurred in eight patients under provocative maneuvers. No predictive factors of a successful provocative maneuver were detected with regard to the baseline patients characteristics and Holter results. In conclusion, patients with focally initiated AF have a low incidence of spontaneous APBs. Various provocative maneuvers successfully increase APBs in more than half of the patients; orciprenaline had the highest efficacy. Some provocative maneuvers may suppress APBs in the setting of high focal activity at baseline.
authors.affiliation: ventura@uke.uni-hamburg.de
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Ventura
authors.forename: Christian
authors.initials: C
authors.lastname: Weiss
authors.forename: Stephan
authors.initials: S
authors.lastname: Willems
authors.forename: Nina
authors.initials: N
authors.lastname: Sturm
authors.forename: Hanno
authors.initials: H
authors.lastname: Klemm
authors.forename: Thomas
authors.initials: T
authors.lastname: Meinertz
mesh_terms: D000241:Adenosine; D000320:Adrenergic Fibers / Q000502:physiology; D001281:Atrial Fibrillation / Q000150:complications* / Q000503:physiopathology; D018880:Atrial Premature Complexes / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D015716:Electrocardiography, Ambulatory; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006801:Humans; D008297:Male; D009921:Metaproterenol; D008875:Middle Aged; D011412:Propanolamines; D012965:Sodium Chloride; D014630:Vagus Nerve / Q000502:physiology
chemical_list: D011412:Propanolamines; D012965:Sodium Chloride; D009921:Metaproterenol; D000241:Adenosine; C036604:esmolol