A 60-year-old woman with atrial fibrillation.

DR REYNOLDS: Mrs B is a 60-year-old retired teacher with atrial fibrillation (AF). She is married and has 2 daughters. She lives near Boston and has commercial health insurance. In December 2000, Mrs B experienced several selflimited episodes of palpitations and throat tightness. A stress test was negative for anginal symptoms or ischemic electrocardiogram changes at a high workload; a thyroidstimulating hormone test was within normal limits. In May 2001, she experienced a severe episode of palpitations and was sent to a local emergency department where she was found to be in AF with a moderate ventricular response. She was treated with intravenous diltiazem and spontaneously converted to sinus rhythm. She was referred to a cardiologist, who recommended aspirin and use of a -blocker as needed to control palpitations. An echocardiogram showed a mildly enlarged left atrium, but was otherwise normal. A Holter monitor showed nonsustained runs of atrial tachycardia, but no AF. Later that year, Mrs B began to experience more frequent palpitations, and a loop recorder showed that of 9 symptomatic episodes, 5 were AF. At that point, she was having episodes once or twice weekly, lasting 8 to 10 hours. She had begun taking the -blocker twice daily, as instructed by her cardiologist. He recommended that anticoagulation be deferred for several years and noted that she could consider an antiarrhythmic agent such as flecainide if her symptoms became intolerable. In September 2002, Mrs B was seen for a preoperative evaluation before planned cataract surgery. Although asymptomatic, she was found to be in AF with a ventricular rate of 80 to 100/min. Mrs B then began anticoagulation, monitored by nurses in her primary care physician’s practice. Her goal international normalized ratio (INR) was 2.0 to 3.0; she drives longer than an hour to the hospital twice monthly to get her INR checked by fingerstick. Her past medical history is significant for hypothyroidism (she is euthyroid with her use of levothyroxine) and hypercholesterolemia. Her current medications are warfarin (2 mg/d), levothyroxine (0.125 mg/d), and metoprolol (50 mg/d). She drinks up to 2 glasses of wine daily; when her AF was paroxysmal, she thought wine might have contributed to her episodes of palpitations. She does not smoke, and she exercises regularly. Mrs B’s mother had coronary heart disease, coronary artery bypass surgery, AF, hypothyroidism, and a history of gastrointestinal bleeding. She died in May 2002 after a large embolic stroke. She had not been a candidate for anticoagulation because of her previous gastrointestinal bleeding. Mrs B’s father died at age 70 years of a brain tumor. On physical examination in November 2002, Mrs B had a blood pressure of 120/80 mm Hg. Her heart rate was approximately 100/min and irregularly irregular. Her cardiovascular examination was otherwise unremarkable. An electrocardiogram showed AF with a ventricular rate of approximately 100/min. She had nonspecific ST-T wave changes. A recent thyroid-stimulating hormone test was within normal limits; her recent total cholesterol value was 291 mg/dL (7.54 mmol/L) (high-density lipoprotein cholesterol, 75 mg/dL [1.94 mmol/L]; ratio, 2.9). Mrs B is currently experiencing some mild shortness of breath with exertion and some fatigue that she attributes to her AF. After discussion of the benefits and risks with her cardiologist, she is considering elective cardioversion, followed by flecainide therapy. She hopes that sinus rhythm would improve some of the mild symptoms she has been having, and that she could stop taking warfarin if she maintains sinus rhythm.