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Arrhythmias after coronary bypass surgery
Insights
Atrial fibrillation is common after coronary artery bypass surgery. Beta-blocker therapy, like propranolol, can significantly reduce its occurrence, unlike digoxin.
Area of Science:
- Cardiology
- Cardiac Surgery
- Electrophysiology
Background:
- Atrial fibrillation (AF) is a frequent complication following coronary artery bypass grafting (CABG).
- Understanding AF's incidence, causes, and prevention is crucial for patient outcomes.
Purpose of the Study:
- To investigate the incidence, causes, and prevention of atrial fibrillation after coronary bypass surgery.
- To evaluate the efficacy of digoxin and propranolol in preventing AF post-CABG.
Main Methods:
- Prospective study of 90 patients undergoing CABG.
- Bedside and ambulatory electrocardiographic monitoring.
- Randomized groups: control, digoxin, and propranolol.
Main Results:
- Control group: 27% incidence of atrial fibrillation.
- Propranolol reduced AF incidence to 14.8%; digoxin had no effect and increased ventricular extrasystoles.
- Myocardial ischemic time and bundle branch block correlated with AF occurrence.
Conclusions:
- Atrial fibrillation is common after CABG, potentially due to myocardial ischemia or hypothermic injury.
- Beta-blockade (propranolol) effectively reduces AF incidence post-CABG.
- Digoxin is not effective for AF prevention and may increase ventricular arrhythmias.
Abstract:
Ninety patients undergoing coronary bypass surgery were studied prospectively by bedside and subsequent ambulatory electrocardiographic monitoring to investigate the incidence, possible causes, and prevention of atrial fibrillation. Patients with good left ventricular function were divided randomly into a control group or groups treated with digoxin or propranolol. In the control group the incidence of atrial fibrillation was 27% and of significant ventricular extrasystoles 3%. Propranolol reduced the incidence of atrial fibrillation (14.8%), whereas digoxin had no effect and increased the incidence of ventricular extrasystoles. Age, sex, severity of symptoms, cardiomegaly, heart failure, previous myocardial infarction, and number of grafts did not affect the result. The operative myocardial ischaemic time was related to the occurrence of atrial fibrillation. There was also a significant relation between atrial fibrillation and bundle branch block. Atrial fibrillation is common after coronary artery grafting; it may be due to diffuse myocardial ischaemia or hypothermic injury. The incidence may be reduced by beta blockade.