Assuntos
Doenças Cardiovasculares/etiologia , Hipoglicemiantes/uso terapêutico , Insulina/uso terapêutico , Gravidez em Diabéticas/tratamento farmacológico , Efeitos Tardios da Exposição Pré-Natal , Rigidez Vascular , Função Ventricular Esquerda , Remodelação Ventricular , Fatores Etários , Biomarcadores/sangue , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Doenças Cardiovasculares/diagnóstico por imagem , Doenças Cardiovasculares/fisiopatologia , Estudos de Casos e Controles , Ecocardiografia , Feminino , Idade Gestacional , Hemoglobinas Glicadas/metabolismo , Humanos , Lactente , Recém-Nascido , Estudos Longitudinais , Masculino , Gravidez , Gravidez em Diabéticas/sangue , Fatores de Risco , Ultrassonografia Pré-Natal/métodosRESUMO
BACKGROUND: The aim of this study was to evaluate left ventricular function in preterm infants from 28 days to near term using echocardiography. METHODS: Thirty clinically stable preterm infants delivered at <30 weeks' gestational age were prospectively enrolled. At 28 days, conventional, tissue Doppler, and speckle-tracking echocardiography evaluations of left ventricular function were performed, with comparison made to findings in 30 healthy term infants of similar postnatal age. Sixteen preterm infants underwent repeat examinations near term. RESULTS: Compared with controls, preterm infants at 28 days had decreased peak mitral valve (MV) E-wave velocities (P < .01), E/A ratios (P < .0001), annular e' velocities (P < .0001), and e'/a' ratios (P < .0001); increased MV E/e' ratios (P < .01); and lower basal circumferential early diastolic and higher late diastolic strain rates. No significant differences were found in fractional shortening, ejection fraction, and longitudinal or circumferential strain and strain rate between preterm infants and controls. Although preterm infants at 28 days had higher heart rates compared with controls (161 ± 15 vs 142 ± 16 beats/min), no significant correlations existed between heart rate and MV E, E/A ratio, e', e'/a' ratio, and E/e' ratio. Near term, the differences in diastolic function persisted, including decreased MV e'/a' ratio (P < .05), increased E/e' ratio (P < .01), and increased late diastolic strain rate. CONCLUSIONS: Clinically stable preterm infants have normal left ventricular systolic function but altered diastolic function, with greater dependence on atrial contraction, the latter of which persists despite nearing term. These findings may be relevant to the management of preterm infants and may relate to the longer term myocardial dysfunction observed in affected adults.