ACE Inhibitor and Renin–Angiotensin System the Cornerstone of Therapy for Systolic Heart Failure

Heart failure (HF) can be defined as an abnormality of cardiac structure or function leading to failure of the heart to deliver oxygen at a rate commensurate with the requirements of the metabolizing tissues, despite normal filling pressures (or only at the expense of increased filling pressures) [1]. HF can be also defined, clinically, as a syndrome in which patients have typical symptoms (e.g. breathlessness, ankle swelling, and fatigue) and signs (e.g. elevated jugular venous pressure, pulmonary crackles, and displaced apex beat) resulting from an abnormality of cardiac structure or function. The diagnosis of HF, according to the guidelines of the European Society of Cardiology, can be difficult and is based on a criterion of clinical evaluation, which relies on the clinical history, physical examination and appropriate investigations [2]. For this reason is more important the need to obtain objective evidence of a structural or functional cardiac abnormality that is thought to account for the patient’s symptoms and signs, to secure the diagnosis of HF.