Circulation
-
Historical Article
Research related to surgical treatment of coronary artery disease.
In the past 20 years, basic and clinical research have provided new information on coronary artery surgery. For example, several studies have shown that coronary artery bypass grafting is more effective than medical treatment in relieving the symptoms of chronic disabling angina pectoris. ⋯ What factors in the patient, in the operation and in the care after operation determine success in surgical treatment? Does the operation prolong useful life? Is the operation affordable? These questions are difficult. Further research is needed to solve complex problems relating to surgical vs medical treatment of coronary artery disease.
-
The prostaglandin synthetase inhibitor indomethacin was given orally or intravenously to pregnant ewes. This resulted in a significant rise in the fetal pulmonary-to-systemic arterial mean blood pressure difference across the ductus arteriosus, presumably secondary to constriction of the ductus arteriosus. In five experiments the pressure difference could be promptly but temporarily reversed by the administration of prostaglandin E1 (PGE1) into the fetal inferior vena cava. ⋯ Indomethacin administration during pregnancy causes constriction of the fetal ductus arteriosus, fetal pulmonary arterial hypertension, and right ventricular damage. If severe, this may cause rapid fetal death. If less severe, in the newborn infant, this mechanism may be one cause of persistent pulmonary hypertension due to vasoconstriction and increased pulmonary arterial smooth muscle and/or tricuspid insufficiency due to papillary muscle infarction.
-
Arterial hypoxemia is a common finding in acute pulmonary embolism, and its severity is generally assumed to be proportional to the extent of pulmonary artery obstruction. We studied blood gases (during room air breathing and 100% oxygen breathing) and hemodynamic data is seven patients with massive pulmonary embolism and circulatory failure. ⋯ We observed that a low cardiac output state can result in a misleading improvement in arterial oxygenation during massive pulmonary embolism, and that an improved circulatory status resulting from medical therapy (including inotropic drug infusion with or without blood volume expansion) can paradoxically increase arterial hypoxemia. We conclude that severity of arterial hypoxemia may not reflect the severity of pulmonary artery obstruction in acute pulmonary embolism if shock is present.