Background: The short-term effect of acute biventricular pacing on cardiac function in patients with chronic heart failure undergoing heart surgery is widely unknown. The present study was designed to determine whether mitral annular tissue Doppler imaging (TDI) is useful to predict acute changes in global systolic function determined by the continuous cardiac output method that was measured postoperatively during various pacing configurations in patients with depressed left ventricular (LV) function.
Methods: TDI peak velocities of systolic (Sm), early diastolic (Em), and late diastolic (Am) mitral annular motion waves were measured in 17 patients (age 67 +/- 8 years, 10 male) with depressed LV systolic function (LV ejection fraction < or = 35%) and QRS duration > 120 ms undergoing temporary epicardial biventricular pacing after aortocoronary bypass and valve surgery. TDI velocities, QRS duration on surface electrocardiogram, cardiac index (CI), right atrial pressure, pulmonary artery pressure, and pulmonary capillary wedge (PCW) pressure were measured simultaneously during various pacing configurations (right atrial-biventricular, right atrial-LV, right atrial-right ventricular, atrial inhibited, and no pacing).
Results: Univariate linear regression analysis showed a good correlation between Am and CI (r = 0.53, P = .0001) determined in all pacing modes, a weak correlation between Sm and CI (r = 0.31, P = .017), and no correlation between Em and CI (r = 0.21, P = .074). Am > 6 cm/s predicted a CI of 2.5 L/min/m(2) or more with a sensitivity of 95% and a specificity of 30%. All TDI values correlated negatively with PCW (r = -0.53, P = .0001 for Sm; r = -0.34, P = .01 for Em; r = -0.50, P = .0001 for Am). Am greater than 6 cm/s predicted a PCW of 16 mm Hg or less with a specificity of 100% and a sensitivity of 34%. Mean values of TDI velocities and hemodynamic parameters were not significantly different between each pacing configuration.
Conclusions: Peak Am mitral annular velocity correlates well with CI and PCW, respectively, thus providing an easy means to assess LV systolic function and pulmonary congestion during cardiac pacing in chronic heart failure.