INCREASED LEFT-VENTRICULAR DIASTOLIC CHAMBER STIFFNESS IMMEDIATELY AFTER CORONARY-ARTERY BYPASS-SURGERY

Objectives. The aim of this study was to assess the incidence and seve rity of left ventricular diastolic dysfunction immediately after coron ary artery bypass surgery by utilizing simultaneous transesophageal ec hocardiographic and hemodynamic monitoring. Background. Left ventricul ar diastolic dysfunction has been documented after coronary bypass sur gery, but its measurement has been technically difficult to acquire an d limited by dependence on loading conditions. Methods. End-diastolic pressure area curves, were constructed before and immediately after co ronary bypass surgery in 20 patients. Transesophageal echocardiographi c images at the mid papillary level of the left ventricle and hemodyna mic data were recorded. Volume status was manipulated to alter loading conditions, and multiple measurements were taken at each loading cond ition. Results. Diastolic function worsened in all patients, as manife sted by a postoperative leftward shift of the end-diastolic pressure a rea curve. At a comparable preload, mean end-diastolic area +/- SEM de creased by 15% from 17.6 +/- 0.8 to 14.9 +/- 0.8 cm(2) postoperatively (p = 0.0001). Conclusions. Left ventricular diastolic chamber stiffne ss fre- quently increases immediately after coronary artery bypass sur - gery. Simultaneous hemodynamic and transesophageal echocar- diograph ic monitoring, through the construction of end-diastolic pressure area curves, is a useful method to evaluate diastolic function and guide m anagement after cardiac surgery.