The Cardiac learning guide is an overview of the anatomy and physiology of a healthy heart. It also provides an explanation of the pathophysiology of two common conditions – acute coronary syndrome and heart failure. It reviews information on the role of cardiac biomarkers in the diagnosis, prognosis, risk stratification, and therapy monitoring of various heart conditions. The Guide is intended to serve the basic educational needs of healthcare professionals who are involved in the laboratory or who manage patients who have or are at risk of developing heart disease.