<h3>Your Heart Has Nine Lives: Nine Steps to Heart Health.</h3> By Alton Blakeslee and Jeremiah Stamler. 269 pp. $4.95. Prentice-Hall, Englewood Cliffs, NJ, 1963 <i>Your Heart and Common Sense</i>distills our knowledge about the heart and imparts it to the layman. In an effective introduction the reader learns first about structure and function, then about rheumatic and coronary heart disease, hypertension, heart failure, and other conditions. Chapters on drugs, diet, the digestive system, tools of cardiology, and general advice complete the book. In certain passages explanation blends effectively with description, philosophical reflections mingle well with rules of thumb, and the author achieves the style of a doctor talking to his patient. But the book lacks overall unity and balance. In recounting his lifetime of experience the author becomes expansive, inserting extraneous material which interferes with orderly transition and discourages the general reader. Heart patients can be urged to read some