RESUMO
The current study aimed to investigate the anti-atrial fibrillatory (AF) effects of a combination of valsartan and a calcium channel blocker (cilnidipine or amlodipine) in Dahl salt-sensitive (Dahl S) rats. Seven-week-old male Dahl S rats were fed an 8% salt diet. Six weeks later, valsartan (60 mg/kg, Val group), cilnidipine + valsartan (10 + 60 mg/kg, CV group), amlodipine + valsartan (3 + 60 mg/kg, AV group), or vehicle was orally administered daily for 5 weeks. Echocardiography and atrial electrophysiological evaluations were performed on the last day of treatment. Blood pressure in each drug treatment group was lower than in the Vehicle group. The duration of AF induced by atrial burst stimulation was shorter in the Val group (3.2 ± 1.6 s) than in the Vehicle group (11.2 ± 6.0 s), which was further shortened in the CV and AV groups (1.1 ± 0.3 and 1.3 ± 0.3 s, respectively). Left ventricular ejection fraction and left ventricular fractional shortening were greater in the CV and AV groups than those in the Vehicle group. Urinary albumin excretion in the CV group was the lowest among the drug-treated groups. The results collectively suggest that the combination of a calcium channel blocker with valsartan could be useful in terms of its anti-AF action as well as for improving cardiac and renal functions.