Useful Understanding of Postoperative Atrial Fibrillation
To the Editor:
Hogue et al1 concluded: “In the hour before AF [atrial fibrillation] after CABG surgery, higher heart rate and lower heart rate complexity compared with values in control patients were independent predictors of AF.” Their careful study and stochastic analyses showed that this was statistically significant, but their observations were not clinically significant for the following reasons.
After CABG operations, many patients have AF for a few minutes or hours without a fast ventricular rate or emboli. Even new AF that lasts for a day or more usually disappears spontaneously without bad results. In a series of 100 consecutive patients who had cardiac operations, all patients who entered the hospital in regular sinus rhythm left the hospital in regular sinus rhythm in spite of intervening AF.2 Predicting harmless as well as harmful AF as a single set does not influence treatment or help the patients in other ways.
Concerning patients who acquire AF after acute myocardial infarction (MI), the American College of Cardiology/American Heart Association stated, “Although AF after acute MI is usually transient, heparin therapy should be given to patients not already receiving it.”3 Hogue et al1 reported 1 patient who had AF and then appeared to have a fatal cerebral embolism on postoperative day 2. There was time to give this patient heparin, and the patient probably received it. Predicting that the patient would have AF would not have helped.
Predicting which patients will have persistent hazardous AF is a different matter. Such a prediction would justify vigorous treatments in these few patients to prevent AF. Such treatment would not be reasonable for all patients at risk for this arrhythmia after CABG operations.
- Copyright © 1999 by American Heart Association
Hogue CW Jr, Domitrovich PP, Stein PK, Despotis GD, Re L, Schuessler RB, Kleiger RE, Rottman JN. RR interval dynamics before atrial fibrillation in patients after coronary artery bypass graft surgery. Circulation. 1998;98:429–434.
Ryan TJ, Anderson JL, Antman EM, Braniff BA, Brooks NH, Califf RM, Hillis LD, Hiratzka LF, Rapaport E, Riegel BJ, Russell RO, Smith EE Jr, Weaver WD. ACC/AHA guidelines for the management of patients with acute myocardial infarction: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol. 1996;28:1328–1428.