[How I treat...persistent atrial fibrillation, by internal cardioversion, in a patient with exreme obesity]

An ethylic hypertensive patient with a BMI of 51.4 developed persistent atrial fibrillation with high ventricular rates. External electrical cardioversion was attempted, but failed in spite of high energy shocks (350 joules). Sinus rhythm was restored by internal cardioversion (12 joules). The value and indications of the techniques are briefly discussed.