To take the pulse of cardiology, tap into the American Heart Association's exhaustive Web site. Study the warning signs of stroke and heart attack. Check out the difference between soluble and insoluble fiber, the role of antioxidants, and the dangers of dietary cholesterol in the nutrition section. At other stops, learn about digitalis, CPR, pacemakers, decongestants, cardiac CAT scans, and much more. The "Heart and Stroke A-Z Guide" is a particularly valuable information source.