Valsartan to Prevent Left Ventricle Remodeling in Pacemaker Patients

Dual chamber pacing is known to induce left ventricle remodeling and may eventually lead to heart failure. The investigators aim to test hypothesis that valsartan started immediately after dual chamber pacemaker implantation will prevent left ventricle remodeling in twelve months long follow up in comparison with placebo. Echocardiographic assessment of left ventricle remodeling will be correlated with plasma activity of matrix metalloproteinases and their tissue inhibitors, indices of functional capacity such as plasma level of NTproBNP and distance in meters during six minute walking test.