The effects of the pericardium on length-dependent regulation of left ventricular function in coronary artery surgery patients

Objective: To analyze the effects of the pericardium on the length-dependen t regulation of myocardial function in coronary artery surgery patients. Designs Prospective. Setting: University hospital. Participants: Patients scheduled for elective coronary artery surgery. Interventions: In 10 patients, a combined micromanometer transducer conduct ance catheter was inserted into the left ventricle for measurement of left ventricular pressures and volumes. Measurements and Main Results: Consecutive data were obtained during a prog ressive increase in Left ventricular pressures and volumes obtained by leg elevation in closed chest-closed pericardium and open chest-open pericardiu m conditions. Pericardiotomy did not alter baseline left ventricular hemody namics. The effects of leg elevation were different, however. In closed che st-closed pericardium conditions, stroke volume and stroke work remained un changed, whereas these parameters increased in open chest-open pericardium conditions. This increase was related to the increase in end-diastolic volu me that was observed in open chest-open pericardium conditions and not in c losed chest-closed pericardium conditions. Conclusions: In coronary artery surgery patients, pericardiotomy does not a lter baseline left ventricular function. When cardiac load is increased by leg elevation, however, use of the Frank-Starling mechanism is enhanced in open: chest-open pericardium conditions. Copyright (C) 2001 by W.B. Saunder s Company.