Myocardial Performance in Asphyxiated Full-Term Infants Assessed by Doppler Tissue Imaging

Abstract

The aim of this study was to assess myocardial performance of full-term infants with perinatal asphyxia using Doppler tissue imaging (DTI) and to correlate it with serum cardiac troponin T (cTnT) concentrations. Twenty-five asphyxiated and 20 nonasphyxiated term infants were investigated. Serum cTnT concentrations were measured between 12 and 24 h of life. Conventional two-dimensional Doppler echocardiography and DTI were done during the first 72 h of life. Right ventricular (RV) and left ventricular (LV) Tei indexes were significantly higher in asphyxiated neonates (mean +/- SD: 0.45 +/- 0.05 vs. 0.28 +/- 0.05, P < 0.001 and 0.51 +/- 0.04 vs. 0.38 +/- 0.04, P < 0.001, respectively). Mitral and tricuspid systolic (Sm) velocities were significantly lower in asphyxiated neonates (mean +/- SD: 5.06 +/- 0.89 vs. 6.89 +/- 0.94 cm/s, P < 0.001 and 5.78 +/- 0.58 vs. 6.69 +/- 0.87 cm/s, P < 0.001, respectively). cTnT concentrations were significantly higher in asphyxiated neonates [median (range): 0.17 (0.05-0.23) vs. 0.03 (0-0.07) microg/l, P < 0.001)], and they correlated positively with the LV Tei index (r = 0.67, P < 0.001) and the RV Tei index (r = 0.68, P < 0.001) and negatively with the mitral systolic (Sm) velocity (r = -0.68, P < 0.001) and tricuspid systolic (Sm) velocity (r = -0.41, P = 0.01). A higher cTnT was a significant predictor of mortality, whereas fractional shortening (FS) and DTI measurements did not show any significant predictive value. The DTI technique appears to be more sensitive than conventional echocardiography in the early detection of myocardial dysfunction induced by perinatal asphyxia in full-term infants.