Conditions that result in a heart murmur — aortic stenosis, aortic regurgitation, mitral regurgitation and hypertrophic cardiomyopathy are the most frequent and important — are often associated with turbulence in the bloodstream. The research of Joseph L. Blackshear, M.D., involves the study of von Willebrand factor, a clotting protein that is progressively defunctionalized by turbulent blood flow and leads to clinically disabling bleeding.
In an ongoing study, Dr. Blackshear's research group has evaluated patients with aortic stenosis, mitral regurgitation, hypertrophic cardiomyopathy and left ventricular assist devices; patients treated with MitraClip; and patients receiving dialysis. They've found a close correlation between the severity of the turbulence caused by these diseases and the disruption of von Willebrand factor function.
Significance to patient care
Classification of valvular heart disease may overlap moderate or severe designation in up to 40% of patients. Additionally, symptoms of valvular disease — shortness of breath, loss of consciousness and chest discomfort — may be present from the valvular condition or another condition or may be obscure if the patient is inactive.
Similar difficulties are present in defining symptoms in hypertrophic cardiomyopathy. A blood test that is a reliable measure of severity could improve surgical decision-making and medical approaches to the prevention of disease progression.