ABSTRACT
Atrial fibrillation is one of the most common arrhythmias and it is a risk factor for stroke, heart failure, morbidity and mortality. Apelin is a protein with multiple effects on cardiovascular system such as, endothelium-dependent vasodilation, positive inotropy, declining ventricular preload and afterload and increases cardiac contractility. Plasma level of apelin which is a good guiding for evaluation of the severity and treatment of heart failure can be a good prognostic factor in lone AF. In this case-control study, 26 patients with lone AF without any other important disease and 27, age and gender matched controls from 30 to 70 years old were evaluated. Measurement of apelin in serum was performed by ELISA method. There were 26 patients aged 30 to 70 years from both genders and 27 controls. The level of apelin in patients group under 60 years old was 1.88+1.07 ng/ml and in controls group was 1.29+ 0.50 ng/ml and for older than 60 years old, 1.007+ 0.56 ng/ml and 1.41+ 0.93 ng/ml, respectively. Data of this study showed no reduction of apelin in lone AF group under 60 years old, but there is significant reduction in patients older than 60 years old. There is no relationship between sex and apelin level