Introduction: Most of the cardiac surgery done today Is performed with aortic cross-clamping and cardlopleglc arrest. Despite Improvements In cardlopleglc techniques, ventricular dysfunction following cardlopleglc arrest Is a major cause of perloperatlve morbidity and mortality. This experiment wJJJ quantify the changes In left ventricular systolic function with cold cardioplegia. Four measures of cardiac function will be assessed with a volume conductance catheter. Methods and Results: Thirty patients undergoing coronary ar· tery bypass graft surgery had volume conductance and mlcromanometer catheters placed In their left ventricles. Preload reduction was used to measure Eaa (the slope of the end-systolic pressure-volume relationship), EdP/dtMax-eov (slope of dP/dtMax end-diastolic volume relationship), EPLRSW (slope of stroke work end-diastolic volume relationship), Eed (slope of the end-diastolic pressure-volume relationship), and ENegdP/dtMax-EDV (slope of the negative dP/dtMax end-diastolic volume relationship). Eaa decreased from 4.32 ± 2.94 prebypass to 2.52 ± 1.06 mmHglmL postbypass. Conclusion: Cold cardlopleglc cardiac arrest Is associated with postbypass systolic and diastolic ventricular dysfunction, which can be quantitated by volume conductance and mlcromanometer based measurements. (J Card Surg 1994;9{Suppl]:497-502) Despite improvements in cardioplegic techniques, post-cross-clamp ventricular systolic and diastolic dysfunction is a major cause of morbidity and mortality associated with cardiac surgery. The exact etiology of this dysfunction is unknown but myocardial ischemia during the period of cardioplegic arrest is a major con-

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