Treatment of underlying atrial fibrillation: paced rhythm obscures recognition.

OBJECTIVES: The purpose of this study was to evaluate the rate of recognition of atrial fibrillation (AF), use of warfarin and prevalence of cerebrovascular accident (CVA) in paced versus unpaced patients during admission to a tertiary care teaching hospital. BACKGROUND: The presence of AF underlying a continuously paced rhythm may be under recognized and result in a lower rate of anticoagulation and higher incidence of CVA. METHODS: The identification of AF on 12 lead electrocardiogram (ECG) and telemetry, "optimal use" of anticoagulants that is, warfarin or aspirin, when warfarin is contraindicated and history of prior CVA was studied in three groups: 1) group A with continuously paced rhythm on ECG and telemetry (n = 30), 2) group B with intermittently paced rhythm on ECG and telemetry (n = 59), and 3) group C with persistent AF and no permanent pacemaker (n = 50). RESULTS: The identification and documentation of AF was significantly lower in the continuously paced group A (20%) versus the intermittently paced group B (44%). Both groups A and B were substantially lower than unpaced controls. "Optimal use" of anticoagulants was significantly lower in group A (40%) compared with groups B (78%) and C (72%) but was not different between groups B and C. The prevalence of prior CVA was not significantly different between the three groups. CONCLUSIONS: All ECGs in patients with paced rhythm should be examined closely for underlying AF to prevent under-recognition and under-treatment with anticoagulants.

Prophylactic oral amiodarone compared with placebo for prevention of atrial fibrillation after coronary artery bypass surgery.

BACKGROUND: Postoperative atrial fibrillation occurs in 20% to 40% of patients undergoing coronary artery bypass grafting (CABG) and contributes to delayed recovery, increased length of stay, and increased hospital cost. Measures at preventing postoperative atrial fibrillation have had mixed results. We report a double-blind trial comparing oral amiodarone with placebo for the prevention of atrial fibrillation after CABG. METHODS AND RESULTS: All patients undergoing CABG were considered eligible. Exclusion criteria included bradycardia (<50 beats/min), prior Atrial fibrillation, concurrent therapy with antiarrhythmic drugs, or concomitant valve surgery. Patients were given 2 g of amiodarone (73 patients) or placebo (70 patients) in divided doses 1 to 4 days before surgery and 400 mg daily for 7 days postoperatively. Atrial fibrillation occurred in 24.7% (18 of 43) of patients receiving amiodarone and 32. 8% (23 of 70) of patients receiving placebo (P =.30). Heart rate at onset of atrial fibrillation was 133.4 +/- 26.6 beats/min for amiodarone compared with 152.9 +/- 31.6 beats/min for placebo (P =. 04). Duration of atrial fibrillation was 10.2 +/- 8.1 hours for amiodarone compared with 16.2 +/- 27.5 hours for placebo (P =.67). Patients receiving both beta-blockade and amiodarone had a 16.7% incidence of atrial fibrillation compared with 31.9% in the remaining patients (P =.10). Atrial fibrillation was associated with an increased cost of $7011 compared with those who remained in sinus rhythm ($23,869 +/- $20,894 vs $16,857 +/- $5401 in sinus rhythm). Hospital cost of those taking amiodarone was $18,895 +/- $13,267 compared with $18,839 +/- $11,537.18 for placebo (P =.42). CONCLUSION: Postoperative CABG atrial fibrillation is associated with prolonged hospital stay and increased cost. Prophylactic oral amiodarone did not statistically alter the incidence or duration of atrial fibrillation after CABG, although favorable trends were noted. Hospital cost was not affected by therapy with amiodarone.