This study is being done to determine whether or not new blood test(s) can determine the severity of heart conditions. Aortic stenosis, hypertrophic cardiomyopathy, mitral regurgitation, aortic regurgitation, artificial heart valve regurgitation or stenosis, and tricuspid valve regurgitation associated with pacemaker leads are the cardiac disorders under study. The blood tests involve analysis for von Willebrand Factor antigen and activity, von Willebrand Factor multimers, and brain natriuretic peptide (BNP) levels. The results of the blood tests will be compared to the information from the clinically-indicated echocardiogram and one blood test compared to another.