Cardiologia (Rome, Italy)
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Cardiologia (Rome, Italy) · Sep 1999
ReviewThe contribution of the giraffe to hemodynamic knowledge: a unified physical principle for the circulation.
Hemodynamics stands on three main physical principles: the hydrostatic pressure, firstly described by Stevino, the viscous flow pressure, described by Poiseuille and the total hydraulic energy, or Bernoulli's equation. However, neither of these physical principles gives a comprehensive description of the single pressure measurement in the cardiovascular system. Hence, all these principles should be used together to fully describe the physical forces acting in the circulation of blood. ⋯ This unified principle is helpful not only to measure correctly the pressure with a catheter connected to a pressure transducer, but also to give to the pressure measured in a patient with the mercury manometer, a strong connection with the description of the pressure as a physical force acting inside the circulation. In addition it provides a comprehensive view of the cardiovascular system as a closed hydrodynamic system, in which the heart is a pump, that does not normally work to overcome the force of gravity. The question at this point is: are there any pathophysiological conditions in which the heart needs to be confronted with the sudden appearance of the force of gravity inside the cardiovascular system?
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Cardiologia (Rome, Italy) · Jul 1999
Review Case ReportsThrombosis of a mitral valve prosthesis resulting from Staphylococcus epidermidis endocarditis.
A 70-year-old man with a Duromedics mitral valve prosthesis had two episodes of infective endocarditis caused by enterococcus (1994 and 1996). Colonoscopy revealed five polyps. Surgical resection was performed and 2 days later the patient had dyspnea and fever. ⋯ Acute thrombosis of the valve was diagnosed by echocardiography, and the patient died before transesophageal Doppler echocardiography was performed. Post mortem examination revealed mitral valve infective thrombosis. In patients with valvular prostheses, endocarditis is an added thromboembolic risk.