Mayo Clinic offers award-winning medical and health information and tools for healthy living.

The mission of the Texas Heart Institute is to reduce the devastating toll of cardiovascular disease through innovative programs in research, education and improved patient care.

The eMedicine point-of-care clinical reference features up-to-date, searchable, peer-reviewed medical articles organized in specialty-focused textbooks, and is continuously updated with practice-changing evidence culled daily from the medical literature.

Heart Rhythm Society The leading authority on arrhythmia, pacemaker, electrophysiology, sudden death, cardiac arrest, arhythmia, arrythmia, icd

The National Library of Medicine (NLM), on the campus of NIH in Bethesda, Maryland, is the world's largest medical library. It collects materials in all major areas of the health sciences and to a lesser degree in such areas as chemistry, physics, botany and zoology. The collections stand at 5 million items--books, journals, technical reports, manuscripts, microfilms, photographs and images. Housed within the Library is one of the world's finest medical history collections of old (pre-1914) and rare medical texts, manuscripts, and incunabula.

HealthCentral.com is one of the most trusted sources of medical information and up to date news and contains a doctor-approved health encyclopedia of diseases and conditions, the ability to find symptoms and treatments. Also drug information with side effects and interactions

Web site of the American Academy of Family Physicians, a medical specialty society that represents more than 93,700 family physicians and medical students.