Atrial premature beats in patients with focal atrial fibrillation: incidence at baseline and impact of provocative maneuvers.
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.
Ventura
Rodolfo
R
ventura@uke.uni-hamburg.de
Weiss
Christian
C
Willems
Stephan
S
Sturm
Nina
N
Klemm
Hanno
H
Meinertz
Thomas
T
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
D011412:Propanolamines; D012965:Sodium Chloride; D009921:Metaproterenol; D000241:Adenosine; C036604:esmolol