European Society of Cardiology

http://www.escardio.org/Pages/index.aspx

European Association for Cardiovascular Prevention & Rehabilitation

http://www.escardio.org/communities/EACPR/Pages/welcome.aspx

American College of Cardiology

http://www.cardiosource.org/

American Heart Association National Center

http://www.americanheart.org/

 

Canadian Cardiovascular Society

http://www.ccs.ca/home/index_e.aspx

Brief History of Electrocardiography

http://www.ecglibrary.com/ecghome.html