Journal of Cardiovascular Medicine and Cardiology Review Article Cardiac Resynchronization Therapy in Heart Failure: Rationale, Results , Indications, Limits and Perspectives Heart Failure is the result of heterogeneous structural heart diseases, especially ischemic disease, and is becoming increasingly common in all Western countries. Many patients continue to be symptomatic in spite of progress in pharmacological therapy, and the risk of mortality remains high in the most advanced functional classes. Cardiac resynchronization therapy can be used as a therapeutic strategy for alleviating symptoms and reducing mortality in selected patients with heart failure. Cardiac resynchronization therapy provides both immediate and medium/long-term results. The immediate results are the reduced QRS duration, the synchrony restoration between the ventricles and between the lateral and septal walls of the left ventricle, the reduced mitral regurgitation and the increased str...