Right ventricular wall-motion changes after infant open heart surgery--a tissue Doppler study.

BACKGROUND

Right ventricular (RV) dysfunction is a well-recognized complication of cardiopulmonary bypass surgery (CPB) in adults. Infants and neonates may also be at high risk for this due to immature myocardium. Conventional assessment of RV function is just qualitative, but novel tissue Doppler echocardiographic (TDI) markers including peak systolic strain rate (SR) and isovolumic contraction acceleration (IVA) permit noninvasive quantitation of RV function. This study assessed myocardial velocities, IVA and SR in infants and neonates undergoing open heart surgery using TDI to study regional myocardial function perioperatively.

METHODS

Transthoracic TDI data were obtained in the OR before and 24 hours post-CPB on 53 consecutive infants (age 0.39 ± 0.23 years). They were followed with TDI through hospital discharge.

RESULTS

Mean CPB time was 87 ± 49 min (cross-clamp 52 ± 26 min). Peak systolic (STDI ) and diastolic myocardial velocities (ETDI , ATDI ), IVA, and peak SR were recorded in RV and LV from standard views for offline analysis. Postoperatively, LV systolic function and diastolic longitudinal function were unchanged or improved from baseline. LV radial velocities were increased postoperatively indicating adequate support. In contrast, RV longitudinal systolic and diastolic function was significantly diminished after CPB. RV changes persisted through hospital discharge.

CONCLUSIONS

In infants and neonates, perioperative measurements of systolic and diastolic tissue Doppler parameters are feasible and revealed significant RV systolic and diastolic dysfunction post-CPB with preserved LV function. As such, TDI provides a sensitive tool to monitor the infant heart after CPB and may potentially be useful to assess different myocardial protection strategies.