Hemodynamic effects and echocardiographic consequences of tension-free pericardial closure after heart valve surgery

Pericardial closure early after open heart surgery has been shown to consistently lower cardiac output and stroke volume, while mean arterial blood pressure is maintained by an increase in systemic vascular resistance. In 10 patients (seven females) (mean age 65 +/- 4 years) undergoing an open heart valve procedure, the effects of a tension-free pericardial closure technique were studied using thermodilution studies and transesophageal echocardiography. The following variables were recorded: mean arterial pressure, mean pulmonary artery pressure, right atrial pressure, cardiac output, stroke volume, systemic vascular resistance, and systolic and diastolic left ventricular dimensions, and left ventricular wall thickness. Observations were made after the heart was decannulated, both while the pericardium was open and after it had been closed by a tension-free technique, and then after closure of the chest. Further observations were made while the chest remained closed, both before and after the pericardium had been reopened by removing the pericardial suture through the chest wall. Closing the pericardium with the tension-free technique while the chest remained open was followed by a fall in cardiac output by 8% and a 15% fall in systemic vascular resistance (both n.s.). These changes caused a 13% reduction in the mean arterial pressure (p = 0.03). Ejection fraction did not change, and systolic and diastolic left ventricular dimensions decreased by 6% and 4% respectively (both n.s.). Opening the pericardium (1.5 to 2 hours after the end of the operation) while the chest remained closed was not followed by significant change in any of the hemodynamic or echocardiographic variables.(ABSTRACT TRUNCATED AT 250 WORDS)