A 50-year-old university professor originally from South America had a 3-day history of paroxysmal attacks of rapid palpitations accompanied by near syncope and followed by transient flushing of her head and neck. She had a history of rheumatic mitral valve stenosis due to rheumatic fever at age 15, for which successful mitral commissurotomy was performed at age 36. Subsequently, recurrent attacks of paroxysmal atrial fibrillation require digitalis therapy to control the patient’s ventricular rate.
The management prior to this hospitalization was digitoxin 0.1 mg daily (normal values 10–30 ng/mL), a low-sodium diet, and moderate restriction of physical activities. Digitoxin, a long-acting digitalis preparation, has a longer clinical effect then digoxin and thus controls the ventricular rate more efficiently in patients with atrial fibrillation and normal left ventricles (eg, in patients with isolated rheumatic mitral stenosis, the heart rate at rest and especially during activity is more easily controlled with the...