Pulmonary embolism and right heart function: insights from myocardial Doppler tissue imaging.

Background: Acute pulmonary embolism (PE) has significant impact in right heart function. We assess the difference of Doppler tissue parameters among control subjects, patients with pulmonary hypertension, and patients with acute PE. After optimal treatment, the changes of Doppler tissue parameters in patients with PE were assessed.

Methods: A total of 50 patients with acute PE, confirmed by multidetector-row chest computed tomography, were enrolled. Another 70 patients with pulmonary hypertension, but no evidence of PE found by computed tomography, were also enrolled. A total of 100 healthy people without signs of cardiopulmonary dysfunction served as a control group. We assessed left and right ventricular (RV) ejection fraction by Simpson's rule. Doppler tissue parameters were obtained from lateral sides of tricuspid and mitral annulus, and interventricular septum. Myocardial performance index (MPI) of RV was estimated from lateral tricuspid annulus by Doppler tissue imaging, MPI of left ventricle from lateral mitral annulus.

Results: The left ventricular and RV ejection fractions in patients with pulmonary hypertension were lower than for the control group and patients with PE. But the RV-MPI in patients with PE was the lowest as a result of significant prolongation of isovolumic relaxation time (IVRT). One month after anticoagulant treatment, the IVRT and RV-MPI recovered in patients with PE. There was no significant correlation between IVRT and pulmonary artery systolic pressure. By bivariate correlation analysis, the most significant factor correlated to pulmonary artery systolic pressure was peak late diastolic velocity of tricuspid annulus with r 0.67, r(2) 0.45, and P less than .0001.

Conclusions: Acute PE has significant impact in systolic and diastolic function of RV. The higher RV-MPI implies that condition. However, optimal anticoagulant treatment corrects RV dysfunction in patients with PE. After a 1-month course of anticoagulant treatment, RV-MPI diminishes as the result of RV-IVRT reduction.