RESUMO
INTRODUCTION: Diastolic dysfunction may occur in fetuses with intrauterine growth restriction (IUGR) and may be assessed by myocardial tissue Doppler (MTD). We previously have shown that excursion index of the septum primum (EISP) is reduced in IUGR fetuses over 30 weeks because of a higher left atrial pressure. PATIENTS, SETTING, AND DESIGN: The sample was made up of 14 fetuses with IUGR. MTD examination was carried out with the sample volume placed at the basal lateral wall of the left ventricle (LV), interventricular septum (IVS), and free wall of the right ventricle (RV) to determine E'/A' ratios. EISP was calculated as the ratio between the maximal excursion of the septum primum into the left atrium during diastole and the maximal diastolic diameter of the left atrium. Mitral and tricuspid flows were assessed by the conventional Doppler method. OUTCOME MEASURES: Pearson's correlation test was used to analyze the correlations between the parameters. RESULTS: A positive correlation was observed between UARI and E'/A' ratios for RV (r = 0.63, P = .02), IVS (r = 0.59, P = .03), and LV (r = 0.41, P = .15). There was a negative correlation between EISP and IVS E'/A' ratios (r = -0.58, P = .03), and a positive correlation for LV (r = 0.49, P = .08). At the RV position, a weak negative correlation was observed (r = -0.32, P = .26). CONCLUSIONS: A higher left atrial pressure in fetuses with IUGR, indicated by the lower mobility of the septum primum, is accompanied by higher ratios between early and late diastolic myocardial velocities. Placental dysfunction was correlated to septal E'/A' ratios. Fetal MTD can be a useful method to assess severity of placental dysfunction and fetal distress.
Assuntos
Retardo do Crescimento Fetal , Septos Cardíacos/fisiopatologia , Contração Miocárdica , Insuficiência Placentária/etiologia , Disfunção Ventricular Esquerda/etiologia , Função Ventricular Esquerda , Função do Átrio Esquerdo , Pressão Atrial , Estudos Transversais , Ecocardiografia Doppler , Feminino , Retardo do Crescimento Fetal/diagnóstico por imagem , Retardo do Crescimento Fetal/fisiopatologia , Idade Gestacional , Septos Cardíacos/diagnóstico por imagem , Humanos , Insuficiência Placentária/diagnóstico por imagem , Insuficiência Placentária/fisiopatologia , Gravidez , Fatores de Tempo , Ultrassonografia Pré-Natal/métodos , Disfunção Ventricular Esquerda/diagnóstico por imagem , Disfunção Ventricular Esquerda/fisiopatologia , Pressão VentricularRESUMO
OBJECTIVES: The aim of this study was to test the hypothesis that experimental maternal intake of green tea in late pregnancy causes fetal ductus arteriosus constriction, probably because of prostaglandin inhibition. METHODS AND RESULTS: Twelve fetal lambs (pregnancy > 120 days) were assessed before and after maternal administration of green tea (n = 8) or water (n = 4; controls) as the only source of liquid. After 1 week, echocardiography showed signs of constriction of the ductus arteriosus in all fetuses from mothers ingesting green tea, with increase in mean systolic velocity(from 0.70 ± 0.19 m/s to 0.92 ± 0.15 m/s, 31.4%, p = 0.001) and mean diastolic velocity (0.19 ± 0.05 m/s to 0.31 ± 0.01 m/s, 63.1%, p < 0.001), decrease of pulsatility index (2.2 ± 0.4 to 1.8 ± 0.3, 22.2%, p = 0.003) and increase of mean right ventricular/left ventricular diameter ratio (0.89 ± 0.14 to 1.43 ± 0.23, 60.6%, p < 0.001). In the four control fetuses, there were no significant changes. All lambs exposed to green tea also showed at autopsy dilated and hypertrophic right ventricles, which was not present in control fetuses. Histological analysis showed a significantly larger mean thickness of the medial avascular zone of the ductus arteriosus in fetuses exposed to green tea than in controls (747.6 ± 214.6 µm vs 255.3 ± 97.9 µm, p < 0.001). CONCLUSIONS: This study in fetal lambs shows a cause and effect relationship between experimental maternal exposure of green tea and fetal ductus arteriosus constriction in late pregnancy.
Assuntos
Canal Arterial/embriologia , Idade Gestacional , Ovinos/embriologia , Chá/efeitos adversos , Animais , Constrição Patológica/diagnóstico por imagem , Constrição Patológica/patologia , Constrição Patológica/veterinária , Canal Arterial/diagnóstico por imagem , Canal Arterial/patologia , Feminino , Modelos Animais , Gravidez , Antagonistas de Prostaglandina , Ultrassonografia Pré-Natal/veterináriaRESUMO
OBJECTIVE: To test the hypothesis that the aortic isthmus flow index (IFI) is lower in fetuses of diabetic mothers than in fetuses of nondiabetic mothers. STUDY DESIGN: We performed a cross-sectional observational study to assess the IFI in fetuses, with (n = 13) and without (n = 37) myocardial hypertrophy, of mothers with diabetes mellitus and in fetuses of nondiabetic mothers (n = 23). Analysis of variance and Tukey test were used to assess differences among the groups. RESULTS: There were no differences in maternal or gestational age among the groups. In fetuses of diabetic mothers, the mean IFI in fetuses with myocardial hypertrophy was 1.19 ± 0.06, and in fetuses without it was 1.18 ± 0.09. The mean IFI in fetuses of nondiabetic mothers was 1.32 ± 0.07 (P < 0.001). CONCLUSIONS: The IFI in fetuses of diabetic mothers is lower than in fetuses of nondiabetic mothers, possibly as a result of a decreased left ventricular compliance.