Beta blockade to prevent atrial dysrhythmias following coronary bypass surgery.
BACKGROUND
Atrial fibrillation and atrial flutter (AF) frequently complicate coronary artery bypass surgery (CABG) and increase hospital stay as well as morbidity. Studies of drug prophylaxis to prevent AF with beta-adrenergic blocking agents administered in fixed doses have had conflicting results.


METHODS
One hundred patients were randomized to receive metoprolol or placebo following CABG. A dosing algorithm was used to achieve clinically significant beta-adrenergic blockade.


RESULTS
There was no significant difference between the incidence of AF in the metoprolol (24%) and placebo (26%) groups. However, the incidence of AF in all patients having CABG at this institution declined over the period of the study from 31% to 23% (P < .025), in association with the adoption of a continuous technique of cardioplegia delivery.


CONCLUSIONS
Metoprolol is not efficacious for the prevention of post-CABG AF even when dosage is titrated to achieve clinical evidence of beta blockade. It is likely that the adoption of a continuous cardioplegia technique caused a reduction in our incidence of post-CABG AF.
Paull
D L
DL
Section of Cardiothoracic Surgery, Virginia Mason Medical Center, Seattle, Washington, USA.
Tidwell
S L
SL
Guyton
S W
SW
Harvey
E
E
Woolf
R A
RA
Holmes
J R
JR
Anderson
R P
RP
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use*; D001145:Arrhythmias, Cardiac / Q000517:prevention & control*; D001026:Coronary Artery Bypass / Q000379:methods*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006324:Heart Arrest, Induced / Q000379:methods; D006801:Humans; D008297:Male; D008790:Metoprolol / Q000627:therapeutic use*; D008875:Middle Aged
D000319:Adrenergic beta-Antagonists; D000889:Anti-Arrhythmia Agents; D008790:Metoprolol