Patients with aortic stenosis, hypertrophic cardiomyopathy, mitral regurgitation, aortic regurgitation, artificial heart valve regurgitation or stenosis, and tricuspid valve regurgitation associated with pacemaker leads who are referred for clinically-indicated echocardiographic exams at Mayo Clinic, in Jacksonville, Florida will be screened for participation in the study. The plan is to have 292 people take part in this study. This minimal risk study will consist of the recording of patient data, activity and bleeding questionnaires, and collection and analysis of blood samples. Each blood sample will be analyzed for von Willebrand Factor antigen and activity, and von Willebrand Factor multimers, and BNP. Blood samples will be sent to the Mayo Special Coagulation Lab for analysis.