The professional organization for cardiovascular specialists, The American College of Cardiology, has current practice guidelines and a strong patient education section.

The Heart Information Network has current scientific news and general primers on heart disease.

Designed by a Professor of Cardiology, this site has outstanding graphics with detailed explanations of cardiac disease.

MerckMedicus, one of the most innovative and comprehensive medical resources on the Internet. This advertising-free medical portal for today's healthcare professional combines breaking medical news, a wide variety of online learning resources, cutting-edge diagnostic tools, and even the patient's perspective on the world of medicine. MerckMedicus is the convenient solution for professionals who dont have time to log on to numerous medical websites.

WebMD Corporation is the leader in providing services that help physicians, consumers, providers and health plans navigate the complexity of the healthcare system.

HeartInfo.org provides timely and trustworthy patient guides about heart attack, blood pressure, cholesterol, stroke, diet and more.

Several educational videos on heart including overview of the heart disease, various tests including nuclear stress test, cardiac catheterization, transesophageal echocardiogram etc. and treatment modalities including angioplasty and bypass surgery.

The professional society dedicated to cardiac arrhythmias has a thorough discussion of current diagnostic and therapeutic techniques.

Healthfinder® is an award-winning Federal Web site for consumers, developed by the U.S. Department of Health and Human Services together with other Federal agencies. Since 1997, healthfinder® has been recognized as a key resource for finding the best government and nonprofit health and human services information on the Internet.

The American Heart Association site is an excellent overview of cardiac disease, risk factors (including cholesterol), diagnostic test, and treatment options.

Web site that provides educational videos on heart diseases.

Medtronic, Inc. guide to pacemakers and defibrillators.

Guidant, Inc. details of pacemakers, defibrillators, and catheter technology.

St. Jude Medical, Inc. overview of pacemakers, defibrillators, and heart valves.

Boston Scientific, Inc. (Scimed), detailing angioplasty and atherectomy devices.

A leading electrophysiology company.

An explanation of electrophysiology products and procedures.

The professional organization for pulmonary specialists. The American College of Chest Physicans has current practice guidelines and several patient educational guides.

The National Institutes of Health has an excellent discussion of how clinical trials are conducted and classified. Understanding your participation in research trials is highlighted.

The professional society for sleep specialists dedicated to patient education and community awareness on sleep disorders.

Provides information, support and resources to sleep disorder patients and healthcare professionals.

The National Sleep Foundation (NSF) is an independent nonprofit organization dedicated to improving public health and safety by achieving understanding of sleep and sleep disorders, and by supporting sleep-related education, research, and advocacy.