This book focuses on established cardiovascular principles and highlights some of the progress achieved by recent research in the cardiovascular field. The authors report the basic concepts related to the functioning of the cardiovascular system necessary for medical students to understand. To foster learning, in each chapter the fundamental points are highlighted in italics and/or bold. In addition, we have added boxes that contain some more detailed information about physiological mechanisms or clinical aspects are analyzed and described in greater detail. The book describes the structure and function of the heart and vascular system for the reader to understand how the cardiovascular system responds in both health and disease. The book conveys a unified vision of the function of the heart and the vascular system, explaining the complexity of the system that goes far beyond the integrated connection between preload, afterload and cardiac contractility. The endothelium covers the internal part of the whole cardiovascular system; therefore, endothelial physiology is treated in several chapters. Given the importance of coronary circulation in cardiac pathophysiology, this special circulation is described in detail and enriched with the most up-to-date information. Several paragraphs and boxes on clinical implications are dedicated to the principles of electrophysiology and the electrocardiogram. A space is also dedicated to myocardial ischemia/reperfusion injury and cardioprotective procedures. The book is written in a linear and simple language without compromising the scientific rigor of the various topics covered.