Conversion to normal sinus rhythm was spontaneous. The underlying source of the atrial fibrillation should be determined. Possible noncardiac causative conditions include hyperthyroidism, alcohol intoxication, cocaine abuse, and electrolyte imbalance.
Physical examination can help determine the presence of valvular heart disease and heart failure.
Blood evaluation, including electrolyte levels and thyroid function, should be done. An echocardiogram can accurately evaluate the valves and measure left ventricular function. Patients who have had one episode of atrial fibrillation often have subsequent episodes. Preventive heart rate-controlling medications may be used to reduce symptoms if they recur. In general, antiarrhythmic drugs are reserved for patients who have more than one episode of atrial fibrillation.