Heart Point 
A lot to be found here, including regurgitation, causes of valvular disease, therapy and surgeries available. An excellent diagram of regurgitant mitral valve in motion is shown.
http://www.heartpoint.com/valvularheartdx.htmlMedtronic
Explains what heart valves are and how problem valves can be treated. Planning for the future and further resources available.
http://www.medtronic.com/cardiac/heartvalves/intro.html
One Valve For Life
Details on mechanical heart valves and tissue valves. Highlights patient stories and features information on valve durability, hemodynamic performance, operative risk and life expectancy.
http://www.onevalveforlife.com
Stress Management Corner
A discussion about low blood volume, often associated with mitral valve prolapse.
http://www.tmius.com/smcorn26.HTML
Guidelines for the Management of Patients With Valvular Heart Disease
A report of the American College of Cardiology and American Heart Association Task Force on Practice Guidelines.
http://circ.ahajournals.org/cgi/content/full/98/18/1949
euroSCORE for Patients
Provides an interactive tool that allows a patient to work out their own risk for all forms of cardiac surgery such as valve surgery.
http://www.euroscore.org/patienteuroscore2.html
St. Jude Medical
Information on how heart valves work, heart sounds, and types and causes of valvular disease.
http://www.sjm.com/conditions/conditionindex.aspx
The Merck Manual
Looks at stenosis and regurgitation for aortic, mitral and tricuspid valves, their symptoms and signs, diagnosis and treatment. A look at pulmonary valves and idiopathic hypertrophic subaortic stenosis.
http://www.merck.com/mkgr/mmg/sec11/ch89/ch89a.jsp
