The purpose of this book is not to discuss in depth various topics in medicine nor to describe in detail all possible controversial subjects in car­ diology. The primary intention is to describe common cardiac problems with significant controversial viewpoints frequently encountered in our daily practice. This book presents 19 chapters, including the Coronary Arteries in Fatal Coronary Events, Prophylactic Antiarrhythmic Therapy in Acute Myocar­ dial Infarction, Mobile Coronary Care-Is It Really Needed?, The Use of Artificial Pacemakers in Acute Myocardial Infarction, Treatment of Car­ diogenic Shock, Serum Digitalis Level-Practical Value, Factors Modifying the Efficacy of Digitalis, Hyperlipidemia and Vascular Disease, Antianginal Agents for Coronary Heart Disease, Anticoagulation Therapy for Coronary Heart Disease, When to Operate on Congenital Heart Diseases, Indications for Coronary Artery Surgery and Patient Selection, Car­ diomyopathy: Diagnostic Criteria and Classification, Therapeutic Approach to Idiopathic Hypertrophic Sub aortic Stenosis, Current Concepts of Hemiblocks, Physical Activity and Coronary Heart Disease, His Bundle Electrocardiography-Its Clinical Value, Computerized Electrocar­ diography-Its Practical Value, and Echocardiography-Its Practical Value. As the title of the book indicates, the "pro and con" viewpoints are described in each chapter, and the authors final conclusions are expressed at the end of each. It is hoped that the book will be provocative as well as educational and practical. The contents are intended to be clinical, concise, and practical, so that this book will provide all physicians with up-to-date materials that will assist them directly in the daily care of their patients with common cardiac problems.