Myocardial dysfunction in neonatal sepsis: A tissue Doppler imaging study

Objectives: To assess myocardial performance in septic fullterm infants and to correlate it with serum cardiac troponin T concentrations. Design: Prospective, case-control, clinical study. Setting: Neonatal intensive care unit in a university hospital. Patients: Twenty septic and 20 nonseptic full-term neonates. Interventions: None. Measurements and Main Results: Conventional echocardiography, tissue Doppler imaging, and serum cardiac troponin T concentration tests were performed as soon as diagnosis was made. On tissue Doppler imaging measurements, right ventricular and left ventricular Tei indexes were significantly higher in septic neonates compared to nonseptic neonates (mean +/- SD: 0.51 +/- 0.09 vs. 0.28 +/- 0.05, p < .001, and 0.56 +/- 0.07 vs. 0.39 +/- 0.04, p < .001, respectively). Mitral and tricuspid peak annular systolic velocities were significantly lower in septic neonates (mean +/- SD: 4.35 +/- 0.68 vs. 6.89 +/- 0.94 cm/sec, p < .0001, and 5.55 +/- 0.66 vs. 6.69 +/- 0.87 cm/second, p < .0001, respectively). On conventional echocardiography measurements, left ventricular internal diameter at end-diastole was significantly higher in septic neonates (p = .04), whereas cardiac index and left ventricular and right ventricular diastolic functions were not significantly different between septic and nonseptic neonates. Cardiac troponin T concentrations were significantly higher in septic neonates (median [range], 0.19 [0.12-0.32] vs. 0.03 [0-0.07] mg/L, p < .0001), and they correlated positively with left ventricular Tei index (r = .80; p < .0001) and right ventricular Tei index (r = .73; p < .0001), and correlated negatively with mitral peak annular systolic velocity (r = -.70; p < .0001) and tricuspid peak annular systolic (r = -.39, p = .012). Nonsurvivors had significantly higher serum cardiac troponin T concentrations and left ventricular Tei index. Conclusions: Neonatal sepsis is associated with systolic and diastolic myocardial dysfunction. This study provides proof-of-concept data for the use of tissue Doppler imaging in assessment of myocardial dysfunction in septic neonates. Tissue Doppler imaging appears to be more sensitive than conventional echocardiography in the detection of this dysfunction. Serum cardiac troponin T and left ventricular Tei index may have prognostic value in these patients. (Pediatr Crit Care Med 2012; 13:318-323)