This is a comprehensive overview on the ethiology, pathophysiology, clinical and therapeutic aspects of cardiomyopathies. Particular emphasis is given to clinical relevance of basic scientific advances in the field, from genetics to immunology. Controversial therapeutic issues are discussed, and a practical section is devoted to beta-blockade - a novel medical treatment for heart failure. Non-medical treatment options from pacing to cardiomyoplasty, artificial assist devices and transplantation are reviewed.