To determine whether tissue Doppler measurements provide sensitive measures of right ventricular function that correlate with the severity of bronchopulmonary dysplasia (BPD).Study design
21 subjects (6 control subjects with no/mild BPD, 7 patients with moderate BPD, and 8 patients with severe BPD) underwent limited echocardiograms with standard M-mode, mitral and tricuspid inflow velocities, and tissue Doppler features measured. BPD severity was scored by using the NICHD/NHLBI/ORD workshop rating scale by physicians blinded to the echocardiogram results. Groups were compared by using 1-way analysis of variance with post-hoc testing and linear regression.Results
Patients with moderate BPD had a higher early Doppler inflow velocity to the early tissue Doppler velocity ratio (E/E′ ratio;P= .03), corresponding to increased end diastolic pressure, compared with patients with no/mild BPD. Patients with severe BPD had a higher E/E′ ratio (P= .004) than patients with no/mild BPD. Linear regression demonstrated a correlation between BPD category and right ventricle E/E′ (P= .007, R2 = 0.33) and left ventricular myocardial performance index (P= .02, R2 = 0.28).Conclusion
Increasing right ventricle E/E′ ratio correlates with clinical severity of BPD. Abnormal left ventricular myocardial performance index was noted to correlate with the grade of BPD. Further longitudinal studies of tissue Doppler echocardiographic assessment of cardiac function in premature infants with BPD are needed.