Estudo do encurtamento global do átrio esquerdo em fetos de mães diabéticas / Study of global left atrial shortening in fetuses of diabetic mothers

OBJETIVO: Testar a hipótese de que a fração de encurtamento atrial esquerda seja menor nos fetos de mães diabéticas do que em fetos de mães sem doenças sistêmicas. MÉTODOS: Foram examinados, por ecocardiografia, 42 fetos de mães com diabetes prévio ou gestacional e 39 fetos normais de mães sem doença sistêmica (controles), com idades gestacionais a partir da 25ª semana até o termo. A fração de encurtamento atrial esquerda foi obtida pelo quociente diâmetro máximo do átrio esquerdo (AE) - diâmetro mínimo AE/diâmetro máximo AE. Os dados foram comparados pelo teste t de Student, com um alfa crítico de 0,05. RESULTADOS: Os filhos de mães diabéticas apresentaram fração de encurtamento atrial esquerda média de 0,39 ± 0,15 e os fetos do grupo controle de 0,51 ± 0,11. Esta diferença foi significativa, com p < 0,001. CONCLUSÃO: A dinâmica atrial esquerda, com diminuição do seu encurtamento global, está acentuada nos filhos de mães diabéticas. Especulamos que este parâmetro possa ser útil na avaliação da função diastólica ventricular esquerda fetal.

Ductus venosus flow and myocardial hypertrophy in fetuses of diabetic mothers.

OBJECTIVE: To test the hypothesis that the pulsatility index of ductus venosus (PIDV) is greater in the fetuses of diabetic mothers (FDM) with myocardial hypertrophy (MH) than in the FDM with no MH and in the control fetuses of nondiabetic mothers (FNDM). Comparing the results with mitral and tricuspid diastolic peak flows. METHODS: The cross-sectional study included fetuses with gestational ages ranging from 20 weeks to term, divided into the following 3 groups: 56 FDM with MH (group I), 36 FDM with no MH (group II), and 53 FNDM (group III, control). The Doppler echocardiogram assessed the PIDV through the ratio (systolic velocity - presystolic velocity)/mean velocity. The mitral and tricuspid E and A waves were also assessed. RESULTS: The mean PIDV in groups I, II, and III were 1.13 +/- 0.64, 0.84 +/- 0.38, and 0.61 +/- 0.17, respectively. Using ANOVA and the Tukey test, a statistically significant difference was found in the 3 groups (P = 0.015 between groups I and II; P < 0.001 between groups I and III; and P = 0.017 between groups II and III). The mean mitral E wave was significantly greater in group I (0.39 +/- 0.12 m/s) than in groups II (0.32 +/- 0.08 m/s) (P = 0.024) and III (0.32 +/- 0.08 m/s) (P = 0.023). The mean tricuspid E wave was also greater in group I (0.43 +/- 0.1 m/s) than in group III (0.35 +/- 0.10 m/s) (P = 0.031). CONCLUSION: The PIDV is significantly greater in FDM with MH than in FDM with no MH and in FNDM. Because the PIDV may represent modifications in ventricular compliance, this index may be a more sensitive parameter for assessing fetal diastolic function.

Fluxo no ducto venoso e hipertrofia miocárdica em fetos de mães diabéticas / Ductus venosus flow and myocardial hypertrophy in fetuses of diabetic mothers

OBJETIVO: Testar a hipótese de que o índice de pulsatilidade do ducto venoso (IPDV) é maior nos fetos de mães diabéticas (FMD) com hipertrofia miocárdica (HM) do que em FMD sem HM e em fetos controles de mães não diabéticas (FMND) comparando os resultados com os picos de velocidade dos fluxos diastólicos nas valvas mitral e tricúspide. MÉTODOS: Estudo transversal incluindo fetos com idade gestacional entre 20 semanas até o termo, divididos em 3 grupos: 56 FMD com HM (grupo I), 36 FMD sem HM (grupo II) e 53 FMND (grupo III, controle). O Doppler-ecocardiograma avaliou o IPDV através da razão (velocidade sistólica - velocidade pré-sistólica)/velocidade média. As ondas E e A dos fluxos mitral e tricúspide foram também avaliadas. RESULTADOS: A média do IPDV no grupo I foi de 1,13 ± 0,64, no grupo II, de 0,84 ± 0,38 e no grupo III de 0,61±0,17. Aplicando-se a ANOVA e o teste de Tukey, houve diferença estatisticamente significativa entre os 3 grupos (p= 0,015 entre os grupos I e II, p < 0,001 entre os grupos I e III e p = 0,017 entre os grupos II e III). A média da onda E mitral foi significativamente maior no grupo I (0,39 ± 0,12 m/s) do que nos grupos II (0,32 ± 0,08 m/s) (p=0,024) e III (0,32 ± 0,08 m/s) (p=0,023). A média da onda E tricúspide foi também maior no grupo I (0,43 ± 0,1 m/s) do que no grupo III (0,35 ± 0,10 m/s) (p= 0,031). CONCLUSAO: O IPDV é significativamente maior em FMD com HM do que em FMD sem HM e do que em FMND. Como o IPDV pode representar modificações na complacência ventricular, este índice pode ser um parâmetro mais sensível para a avaliação da função diastólica fetal.

Study of global left atrial shortening in fetuses of diabetic mothers.

OBJECTIVE: To test the hypothesis that left atrial shortening fraction is lower in fetuses of diabetic mothers than in fetuses of mothers with no systemic disease. METHODS: Forty-two fetuses of mothers with previous diabetes or gestational diabetes and 39 healthy fetuses of mothers with no systemic disease (controls) underwent echocardiographic examination. Their gestational ages ranged from 25 weeks to term. The left atrial shortening fraction was obtained with the following formula: (left atrial maximum diameter - left atrial minimum diameter)/left atrial maximum diameter. Data were compared using the Student t test, with an alpha level of 0.05. RESULTS: Mean left atrial shortening fractions in fetuses of diabetic mothers and in those in the control group were 0.39 +/- 0.15 and 0.51 +/- 0.11, respectively. This difference was significant with P < 0.001. CONCLUSION: Left atrial dynamics, with a reduction in global left atrial shortening, is increased in fetuses of diabetic mothers. We speculate that this parameter may be useful in assessing fetal left ventricular diastolic function.

Pulsatilidade venosa pulmonar em fetos de mäes diabéticas: estudo Doppler-ecocardiográfico pré-natal / Pulmonary vein pulsatility in fetuses of diabetic mothers: prenatal Doppler echocardiographic study

OBJECTIVE: To verify the hypothesis that the pulmonary vein pulsatility index is higher in fetuses of diabetic mothers than it is in normal fetuses of nondiabetic mothers. METHODS: Twenty-four fetuses of mothers with either gestational or previous diabetes (cases), and 25 normal fetuses of mothers without systemic disease (control) were examined. Fetuses were examined through prenatal Doppler and color flow mapping. The pulmonary vein pulsatility index was obtained by placing the pulsed Doppler sample volume over the right superior pulmonary vein and applying the formula (systolic velocity - presystolic velocity)/mean velocity. RESULTS: The mean gestational age of the study fetuses was 30.3±2.7 weeks, and gestational age of the controls was 29±3.3 weeks, with no significant difference in gestational age between groups (p=0.14). Fetuses of diabetic mothers had a mean pulmonary vein pulsatility index of 1.6±1, and those of the control group had an index of 0.86±0.27. CONCLUSION: Fetuses of diabetic mothers had pulmonary vein pulsatility indexes (parameter easily obtained through Doppler echocardiography that may be related to fetal diastolic function) higher than those in fetuses of mothers with normal glycemia

Dynamics of the pulmonary venous flow in the fetus and its association with vascular diameter.

BACKGROUND: The usual positioning of the Doppler sample volume to assess fetal pulmonary vein flow is in the distal portion of the vein, where the vessel diameter is maximal. This study was performed to test the association of the pulmonary vein pulsatility index (PVPI) with the vessel diameter. METHODS AND RESULTS: Twenty-three normal fetuses (mean gestational age, 28.6+/-5.3 weeks) were studied by Doppler echocardiography. Pulmonary right upper vein flow was assessed adjacent to the venoatrial junction ("distal" position) and in the middle of the vein ("proximal" position). The vessel diameter was measured by 2D echocardiography with power Doppler, and the PVPI was obtained by the ratio (maximal velocity [systolic or diastolic peak]-minimal velocity [presystolic peak])/mean velocity. The statistical analysis used t test and exponential correlation studies. Mean distal diameter was 0.33+/-0.10 cm (0.11 to 0.57 cm), and mean proximal diameter was 0.16+/-0.08 cm (0.11 to 0.25 cm) (P<0.0001). Mean distal PVPI was 0.84+/-0.21 (0.59 to 1.38), and mean proximal PVPI was 2.09+/-0.59 (1.23 to 3.11) (P<0.0001). Exponential inverse correlation between pulmonary vein diameter and pulsatility index was highly significant (P<0.0001), with a determination coefficient of 0.439. CONCLUSIONS: In the normal fetus, the pulmonary venous flow pulsatility decreases from the lung to the heart, and this parameter is inversely correlated to the diameter of the pulmonary vein, which increases from its proximal to its distal portion. This study emphasizes the importance of the correct positioning of the Doppler sample volume, adjacent to the venoatrial junction, to assess pulmonary venous flow dynamics.

Pulmonary vein pulsatility in fetuses of diabetic mothers: prenatal Doppler echocardiographic study.

OBJECTIVE: To verify the hypothesis that the pulmonary vein pulsatility index is higher in fetuses of diabetic mothers than it is in normal fetuses of nondiabetic mothers. METHODS: Twenty-four fetuses of mothers with either gestational or previous diabetes (cases), and 25 normal fetuses of mothers without systemic disease (control) were examined. Fetuses were examined through prenatal Doppler and color flow mapping. The pulmonary vein pulsatility index was obtained by placing the pulsed Doppler sample volume over the right superior pulmonary vein and applying the formula (systolic velocity - presystolic velocity)/mean velocity. RESULTS: The mean gestational age of the study fetuses was 30.3 2.7 weeks, and gestational age of the controls was 29 3.3 weeks, with no significant difference in gestational age between groups (p=0.14). Fetuses of diabetic mothers had a mean pulmonary vein pulsatility index of 1.6 1, and those of the control group had an index of 0.86 0.27. CONCLUSION: Fetuses of diabetic mothers had pulmonary vein pulsatility indexes (parameter easily obtained through Doppler echocardiography that may be related to fetal diastolic function) higher than those in fetuses of mothers with normal glycemia.

Uso de surfactantes pulmonares na Doença da Membrana Hialina / Use of pulmonary surfactants in Hyaline Membrane Disease

Os autores revisam os aspectos clínicos, fisiopatológicos e terapêuticos da Doenca da Membrana Hialina (DMH), dando ênfase à farmacologia dos surfactantes pulmonares (sintéticos e naturais); discutem características de sua farmacodinâmica, farmacocinética, toxicologia, contra-indicaçöes e efeitos adversos