Tissue Doppler imaging (TDI) of the mitral annulus is now widely used in the assessment of LV diastolic function. There is not universal agreement, however, on the optimal site of TDI measurement: some centers record motion of the lateral mitral annulus (LMA) while others favor the septal mitral annulus (SMA). Abnormal septal motion (“post-op septum”) is often seen after cardiopulmonary bypass (CPB), though ejection fraction (EF), end-systolic, and end-diastolic volumes are generally unchanged. If TDI measurements of the SMA are selectively affected by CPB, assessment of diastolic function could be adversely affected. In this study, we analyzed mitral annular TDI measurements following CPB and compared these to changes in patients undergoing off-pump cardiac surgery.
We prospectively studied 8 CPB and 7 off-pump pts. Echocardiography was performed 4±3 days before surgery and again 31±7 days after. Velocity of early diastolic mitral annular motion (Em), transmitral E/A ratio, and ejection fraction (EF) were measured in the apical 4-chamber view & compared using Wilcoxon signed ranks test. Patients served as their own controls.
SMA Em velocity in CPB pts decreased significantly after surgery, while there was a nonsignificant increase in off-pump patients. LMA Em, E/A, & EF were unaffected by CPB, while these parameters trended upward in the off-pump group (although the baseline systolic and diastolic parameters of the off-pump group were depressed compared to the CPB group).
Cardiac surgery with CPB is associated with a statistically significant 20% decrease in SMA Em velocity, despite no change in LMA Em velocity, E/A, or EF. Of note, this decrease in SMA Em is not seen following off-pump cardiac surgery.
Measurement of SMA Em velocity is not recommended for routine assessment of diastolic function after CPB. This parameter may, however, retain its clinical utility after off-pump cardiac surgery. CPB GroupOff-Pump GroupPreOpPostOpP valuePreOpPostOpP valueSMA Em (cm/s)8.16.40.025.56.20.35 (NS)LMA Em (cm/s)10.310.00.93 (NS)6.08.00.06 (NS)EF0.550.560.78 (NS)0.360.460.03E/A1.281.110.50 (NS)1.101.470.10 (NS)
P. Malouf, None.