Blood Velocity and Endocarditis

Abstract

Examination of the problem of infective endocarditis from a hydrodynamic point of view indicates that it is associated with a high pressure source (aorta, left ventricle, etc.) which drives blood at high velocities through a narrow orifice (coarctation, ductus arteriosus, ventricular septal defect, insufficient aortic or mitral valve) into a low pressure sink (pulmonary artery, atrium). The high velocity of the stream immediately beyond the orifice is associated with a marked drop in lateral pressure and perfusion of the intima of this segment is reduced; this is also the characteristic site of the infective process. The infrequency of peripheral nidation and abscess formation despite recurrent bacteremia, and the rapid clearing after surgical correction of high velocity jets, as in ligation of a patent ductus arteriosus, are in accord with the hydrodynamic concept. An analysis of the literature, and experimental studies of the effects of flow on deformable channels and on bacterial growth and chemical reactions are cited in support of this concept.