RIGHT-VENTRICULAR DYSFUNCTION IN LOW OUTPUT SYNDROME AFTER CARDIAC OPERATIONS - ASSESSMENT BY TRANSESOPHAGEAL ECHOCARDIOGRAPHY

Background. Low output syndrome after cardiac operations is associated with high morbidity and mortality rates. The contribution of right ve ntricular dysfunction to this syndrome has not been fully characterize d. The purpose of this study was to evaluate the utility of transesoph ageal echocardiography to identify the frequency and the in-hospital m ortality from right ventricular dysfunction in patients with this synd rome. Methods. Seventy-five consecutive patients undergoing transesoph ageal echocardiography for low output syndrome early after cardiac ope rations were evaluated. The findings from transesophageal echocardiogr aphy were correlated with the type of surgical procedure, cross-clamp time, right heart hemodynamics, and coronary angiography. Results. Rig ht ventricular systolic dysfunction occurred in 36 patients (42%); in 17 patients it was isolated and in 19 patients it occurred in combinat ion with left ventricular dysfunction. Postoperative right ventricular dysfunction was not uniformly associated with important right coronar y artery disease or with prolonged ischemic time during cardiopulmonar y bypass. Hemodynamic data were not useful to distinguish the group wi th postoperative right ventricular dysfunction. Patients with right ve ntricular dysfunction had a high (44%) in-hospital mortality rate. Con clusions. Right ventricular dysfunction occurs frequently in patients with low output syndrome after cardiac operations and is associated wi th a high in-hospital mortality rate. Better understanding of the mech anisms causing postoperative right ventricular dysfunction may provide insight for preventing this complication.