Prevalence of Primary Aldosteronism in Atrial Fibrillation

Screening for primary aldosteronism will be performed with measurement of aldosterone-to-renin ratio after 2 hours of bed rest. Renin measurement will be performed by estimating plasma renin activity. The screening test will be considered positive when the ratio is \>30, accompanied by elevated aldosterone values (\>15 ng/ml). Patients with a positive result will undergo further confirmatory testing with intravenous sodium test (administration 2 liters of normal saline N/S 0.9%, over a period of 4 hours, while the patient is supine. Considered positive if aldosterone levels are \>5mg/dl at the end of the test). Alternative confirmatory methods are captopril test (Administration of 50 mg of captopril. Considered positive when aldosterone levels are \>8.5 mg/dl 2 hours after the intake) or hydrocortisone test (Administration of 0.1mg of hydrocortisone 4 times a day for a period of 4 days. Considered positive if elevated aldosterone levels (\>6ng/dl) are found at the end of the test).