No special news on heart care, and no self-help advice--just the well-presented medical information characteristic of this new series. Once the authors have explained how the heart works, indeed, they head into uncertain ground. ""Virtually everything you have heard about preventing heart disease,"" they write, ""rests on circumstantial evidence."" Still, dietary measures, exercise, and stress reduction are probably worth trying. High cholesterol in the blood has a proven relationship to heart disease; less certain is how diet and other factors are related to blood cholesterol. Exercise is endorsed, since ""the prevailing medical view"" is that it reduces the other risk factors: high blood pressure, obesity, tension. Hypertension, excessive stress, and smoking certainly need to be treated or stopped. The second part of the book deals, in rapid-fire order, with problems and their treatment; heart attack, angina, coronary artery spasm, pacemakers, congestive heart failure, bypass surety, valve disease, and heart transplants are all covered, as well as the artificial heart and other future possibilities. But in explaining what to expect, the authors provide no evaluations of the various procedures. The only specific advice on preventive measures, moreover, is on the final page. James Jackson Nora's The Whole Heart Book (1980) offers more detailed help on prevention, along with guidance in making tough choices; this will serve, however, for a basic orientation.