Candesartan in the Prevention of Relapsing Atrial Fibrillation

Inclusion Criteria: Patients with atrial fibrillation, diagnosed electrocardiographically, of more than 48 hours duration in whom direct current (DC) cardioversion is planned. Exclusion Criteria: Patients with a history of known hypersensitivity or contraindication to any angiotensin II receptor blocker or any angiotensin-converting enzyme (ACE) inhibitor. Patients currently receiving an ACE inhibitor or angiotensin II antagonist because of heart failure or other strong indication. Patients currently receiving any antiarrhythmic medication including sotalol. Other beta-blockers will not be regarded as specific antiarrhythmic agents. Significant renal artery stenosis and any medical condition in which administration of a vasodilator is contraindicated; serum creatinine > 225 micromol/L; or serum potassium > 5.5 mmol/L; or serum sodium < 128 mmol/L. Patients with severe hepatic dysfunction. Life-limiting disease or substance abuse which may affect participation. Patients unwilling to participate. Patients who have previously undergone DC cardioversion for atrial fibrillation within the last month. Thyrotoxicosis. Patients with a systolic blood pressure of < 100 mm Hg. Hypertensive patients requiring intensified treatment prior to DC cardioversion. Pregnancy or lactation.