Transesophageal echocardiographic area and Doppler flow velocity measurements: Comparison with hemodynamic changes in coronary artery bypass surgery

Objective: Changes in transesophageal echocardiography (TEE)-derived Dopple r flow velocities through the mitral valve and pulmonary veins occur after cardiopulmonary bypass and are believed to reflect left ventricular (LV) di astolic functional impairment. The aim of this study was to determine the t ime-coincidence between these Doppler flow velocity parameters, LV two-dime nsional (2D) short-axis area measurements, and hemodynamic parameters in pa tients after coronary artery bypass grafting. Design: Prospective clinical study. Setting: University hospital. Participants: Twenty patients with normal ejection fraction undergoing elec tive cardiac surgery. Interventions: At multiple intervals during surgery and 6 hours postoperati vely, mitral inflow velocity and pulmonary venous flow velocity were measur ed with pulsed Doppler TEE. LV short-axis area by echocardiography and card iac output by thermodilution were simultaneously obtained. Measurements and Main Results: Time-coincidence was found in the immediate postbypass period between a decreased E/A ratio from 1.16 (95% confidence i nterval, 1.0 to 1.31) to 0.64 (95% confidence interval, 0.47 to 0.81, p < 0 .01), a decreased E-wave deceleration time, and a significantly increased h eart rate (HR) and cardiac index. End-diastolic area (EDA) and stroke volum e index (SVI) decreased after sternal closure. HR, E-wave deceleration time , and SVI remained altered until 6 hours postoperatively. No change was fou nd in pulmonary venous flow velocity parameters and systolic LV function. Conclusion: In patients with normal systolic ventricular function and no in otropic support, Doppler flow velocity patterns alone did not sufficiently reflect hemodynamic changes, whereas 2D LV area, especially EDA measurement s, provided useful information about hemodynamically significant LV filling impairment. Copyright (C) 1999 by W.B. Saunders Company.