Myocardial dysfunction in fetuses exposed to intraamniotic infection: new insights from tissue Doppler and strain imaging

OBJECTIVE: The purpose of this study was to assess myocardial function of fetuses who were exposed to intraamniotic infection compared with fetuses of uncomplicated pregnancies by the application of tissue Doppler and strain rate (SR) imaging. STUDY DESIGN: We evaluated the right ventricular function of fetuses with preterm premature rupture of membranes and proven intraamniotic infection (n = 12 fetuses) and healthy fetuses (n = 27). Tissue Doppler velocities during early diastolic relaxation (E(m)) and atrial contraction (A(m)) and early diastolic SR were measured as indices of diastolic function, whereas the peak systolic strain and SR were used as parameters of systolic function. RESULTS: Fetuses with intraamniotic infection exhibit impairment in both diastolic and systolic performance, which was characterized by increased diastolic compliance (increased E(m)/A(m) ratio, increased early diastolic SR compared with the control fetuses), decreased systolic contractile function (reduced systolic strain and SR), and longitudinal myocardial dyskinesia. CONCLUSION: New echocardiographic tools suggest that fetal heart is a target organ in the context of intraamniotic infection.