Introduction: Routine assessment of diastolic function (DF) may reveal early prognostic values for risk stratification and resource utilization in cardiac surgical patients. The purpose of our study was to evaluate the efficacy of colour M-mode propagation velocity (Vp) in determining diastolic dysfunction (DD) during intraoperative transoesophageal echocardiography in patients undergoing coronary revascularization surgery.
Method: With IRB approval, prospective assessment of DF was conducted in 63 patients. Transmitral Doppler flows of early (E) and late (A) ventricular filling velocities, deceleration time (DT) and isovolumic relaxation time (IVRT) were obtained from four chamber midoesophageal and deep transgastric views, respectively. In addition, pulmonary venous flow systolic (S) and diastolic (D) velocities were interrogated. Colour M-mode was used to measure Vp as the slope of the first aliasing velocity during early filling of the left ventricle. The cursor was aligned from the mitral valve plane to 4 cm into the left ventricular cavity. The baseline shift of colour velocity map was adjusted to alias at 75% of the peak E transmitral velocity. A sweep speed of 100 mm s−1 was employed. All measurements were acquired during apnoea. The E/A and S/D ratios were calculated. DD was defined as E/A < 1.0 or S/D < 1.0 (in the presence of E/A > 1). Valsalva manoeuvre was used to identify patients with a pseudonormal pattern. Data was analysed with Fisher's exact test, t-test and ANOVA as appropriate.
Results: DD was present in 44 patients. Delayed relaxation (DR), pseudonormalization (PN) and restrictive (RP) patterns were identified. Vp was <50 cm s−1 in the DD group.
Conclusion: DD is common in cardiac surgical patients. Vp is a simple and valuable measure of DD intraoperatively. Vp <50 cm s−1 can be used to identify an abnormal pattern of diastolic filling even in the presence of normal E/A ratio. The IVRT and DT are important complementary measurements in determining the pattern of DD. Further studies are required to determine if lowered Vp is associated with poor outcome after cardiac surgery.
1 Garcia MJ, Palac RT, Malenka DJ, et al.
Color M-mode Doppler flow propagation velocity is a relatively preload-independent index of left ventricular filling. J Am Soc Echocardiogr