Progressive Ventricular Dysfunction Prevention in Pacemaker Patients

Inclusion Criteria: * Meet Class I and/or Class IIa implantation criteria for permanent cardiac pacing according to the guidelines given by the American College of Cardiology (ACC)/American Heart Association(AHA). Exclusion Criteria: * Expected ventricle stimulation \<80% of the time * Impossibility of dual chamber stimulation in the absence of AF * Severe heart failure (NYHA Functional class III-IV) previous to indication for pacing device implant * Patient needs revascularization within 3 months * Myocardial infarction in the last 3 months * Cardiac surgery performed in the last 3 months * Hypertrophic cardiomyopathy * Constrictive pericarditis * Bad echo window * Previous system implanted (ICD or pacemaker) * Aortic stenosis * Patient has a mechanical right heart valve * Patient \<18 years * Pregnancy * Patient has medical conditions that would preclude the testing required by the protocol, or limit study participation * Life expectancy \<1year * Patient is unwilling or unable to cooperate or give written informed consent. * Patient is or will be inaccessible for follow-up at the study center. * Patients who are participating or planning to participate in other clinical trials during the clinical study