Intracardiac shunts and role of tissue Doppler Imaging in diagnosis and discrimination

ABSTRACT

We sought to assess right ventricular [RV] systolic and diastolic functions via tissue Doppler imaging [TDI] in order to discriminate right-to-left [bidirectional] from left-to-right intracardiac shunts. A tissue Doppler velocity study via Doppler echocardiography was performed in 20 patients with left-to-right shunt [without evidence of significant pulmonary hypertension] and 20 patients with right-to-left shunt or bidirectional shunt [with significant pulmonary hypertension] or Eisenmenger?s complex and 20 healthy subjects as the control group. RV myocardial performance index [MPI], S wave velocity, E wave velocity, isovolumic relaxation time [IVRT], and isovolumic contraction time [IVCT] from the lateral tricuspid annulus were measured using TDI. In the patients with left-to-right shunt, the tissue Doppler parameters showed higher S-wave, peak systolic[Sa]/early contraction[Ea], Sa/IVRT, and Sa/IVCT values; and in the patients with right-to-left or bidirectional shunt tissue, the Doppler parameters showed higher MPI and MPI/Sa value with a high specificity and sensitivity. We conclude that an evaluation of MPI, S wave, E wave, IVRT, and IVCT via tissue Doppler echocardiography is a useful index for the discrimination of right-to-left from left-to-right and bidirectional intracardiac shunts