Determinants and clinical significance of jugular venous valve competence.

摘要: We studied the function of right internal jugular vein valves during cardiac catheterization in 32 patients and external vitro from 13 dogs. Patients with normal central venous pressure had competent cough-induced transvalvular gradients 52.4 +/- 8.6 mm Hg. Ten 15 elevated either incompetent or absent valves, latter occurring only long-standing, severe tricuspid regurgitation. During coughing, were also demonstrated left subclavian veins. The excised canine at a static 81.8 3.7 Five six remained pulsatile 64.8 1.9 Thus, thoracic inlet are usually sudden increases intrathoracic pressure. These may play an important role establishing extrathoracic arteriovenous gradient necessary for forward blood flow cardiopulmonary resuscitation other states high