ECHO parameters of diastolic dysfunction

Abstract

Most patients with cardiac disease have diastolic dysfunction which is characterized by impaired diastolic filling and/or abnormal diastolic relaxation. The trans-esophageal echocardiography (TEE) used routinely during open-heart surgical procedures has exceptional resolution that may permit the identification and grading of diastolic dysfunction. The goal of this study was to determine which echocardiography (ECHO) parameters can best describe diastolic dysfunction due to myocardial remodeling and fibrosis. Baseline transthoracic ECHO was performed on 3-month-old C57BL/6J female mice followed by administration of isoproterenol (2 microg/g/d) for 6 days. On day 7, transthoracic ECHO was performed to determine the change of left ventricular (LV) inflow parameters due to isoproterenol-mediated cardiac remodeling. The mid-LV region was stained with picrosirius red to quantify myocardial fibrosis and demonstrated a 5-fold increase in cardiac fibrosis (p = 0.002). LV mass was increased by 36% (p = 0.0016). Mitral valve flow Doppler peak velocities E and A were measured from a 4-chamber view. The E/A ratio did not change, but the E deceleration time, velocity time integral of the E-A complex (E-A VTI), E/E-A VTI ratio, isovolumic relaxation time (IVRT), and diastolic time all significantly increased. The corresponding tissue Doppler parameter, Ea/Aa ratio, decreased by 25% (p = 0.035). The left atrial dimension and the ECHO index of left atrial pressure (E/Ea) significantly increased (p < 0.02). These data suggest that, with a long-axis and a 4-chamber view, the clinician can adequately determine diastolic function in the open-heart surgical patient.