Coração fetal: por que e quando investigar? / Fetal ultrasound: why explore the heart?

O incremento do arsenal diagnóstico do pré-natal, por meio de exames de ultrassom, com tecnologias de imagens cada vez mais perfeitas, proporciona o estudo detalhado da anatomia fetal. A mortalidade infantil está diretamente relacionada com as malformações congênitas fetais, especialmente com as alterações anatômicas do coração. Aproximadamente 90% das gestantes não apresentam nenhum fator de risco para malformações cardíacas congênitas (MCCs), portanto o rastreamento pré-natal deve ser realizado em todas as gestações, conforme sugestão da primeira Diretriz Brasileira de Cardiologia Fetal. A revisão bibliográfica da literatura sugere que o diagnóstico pré-natal das MCCs permite intervenções fetais durante o pré-natal e adequado planejamento do parto. Essas ações interferem na morbiletalidade perinatal e no prognóstico dos fetos portadores de cardiopatias, além de auxiliarem a equacionar as vagas nos hospitais de referência e estimarem os gastos na saúde pública e privada.(AU)

The improvement of the ultrasound scan used in the prenatal evaluations provides better images data for the study of the fetal heart. Congenital heart malformations are one of the most leading causes of infant death in the world. Ninety percent of pregnant women do not present any risk factors for Congenital Heart Malformations, so prenatal screening should be performed in all pregnancies, as suggested by the first Brazilian Guideline on Fetal Cardiology. The literature review propose that prenatal diagnosis of congenital heart malformations supports fetal care satisfactory delivery planning and interventions during prenatal. These kindness influences the prognosis of the cardiopathies, perinatal morbidity and mortality and help to reorganize hospital admission and public health care.(AU)

Taquicardia sinusal inapropriada: o papel da ecocardiografia fetal transvaginal: relato de caso / Inappropriate sinus tachycardia: the role of trasvaginal fetal echocardiography: case report / Taquicardia Sinusal Inapropiada: El papel de la Ecocardiografía Fetal Transvaginal ­ Relato del Caso

Introdução: A taquicardia sinusal inapropriada é rara na população em geral, tem maior prevalência em mulheres jovens e sua etiologia é desconhecida. Caracteriza-se por uma frequência cardíaca, persistentemente, elevada com uma resposta exagerada à atividade física. Objetivo: Relatar um caso raro de taquicardia sinusal inapropriada em fase precoce da gestação, enfatizando a importância da ecocardiografia fetal transvaginal. Relato de caso: Gestante encaminhada para realização de ecocardiografia transvaginal por taquicardia fetal persistente. Ao exame de nove semanas, o feto apresentava uma FC de 240 batimentos por minuto (bpm), com condução atrioventricular de um para um e sem sinais de hidropisia. Utilizados a digoxina e, posteriormente, o flecainide, ambos sem sucesso terapêutico. Iniciado sotatol com redução gradual e posterior normalização da FC fetal. O parto ocorreu a termo, concepto nasceu bem e evoluiu com taquicardia persistente. O eletrocardiograma realizado demonstrou onda P com morfologia de ritmo sinusal. As possíveis causas de taquicardia sinusal foram afastadas, confirmando assim o diagnóstico acima. Comentários: O autor reforça a importância da ecocardiografia fetal transvaginal para o diagnóstico e tratamento precoce de arritmias fetais, evitando complicações.

Introduction: The inappropriate sinus tachycardia is rare in the general population, more frequently affects young women, and its etiology is unknow. It is characterized by a persistently elevated cardiac frequency with na exaggerated response to physical activity. Objective: Report a rare case of inappropriate sinus tachycardia in the early phase of pregnancy and emphasize the importance of transvaginal fetal echocardiography. Case report: Pregnant referred due to persistente fetal tachycardia after obstretic ultrasonography. The transvaginal echocardiogram performed at 9 weeks' gestation showed a fetal heart rate of 240 beats min (bpm) with normal conduction from atria to ventricle (1:1)and no signal hydropsy. Digoxin therapy and Flecainide were used with no sucess. Sotatol use was chose when the fetal heart rate (HR) reduced to tolerable levels and then the number of heartbeats normalized at thirty six weeks gestation. The baby was born well at term and developed persistente tachycardia. The electrocardiogram performed showed P-ware morphology of sinus rhythm. Possible causes of sinus tachycardia were excluded, thus confirming the diagnosis above. Comments: The author describes the imortance of transvaginal fetal echocardiography for the diagnosis and early treatment of fetal arrhythmias avoiding complications.

Introducción: La taquicardia sinusal inapropiada es rara en la población en general, predomina mayormente en mujeres jóvenes y su etiología es desconocida. Se caracteriza por una frecuencia cardíaca, persistentemente, elevada con una respuesta exagerada a la actividad física. Objetivo: Relatar un caso raro de taquicardia sinusal inapropiada en fase precoz de la gestación, enfatizando la importancia de la ecocardiografía fetal transvaginal. Relato del caso: Gestante derivada para la realización del ecocardiograma transvaginal por taquicardia fetal persistente. En el examen de nueve semanas, el feto presentaba una FC de 240 latidos por minuto (lpm), con conducción aurículoventricular de uno para uno y sin señales de hidropesía. Se utilizó la digoxina y, posteriormente, el flecainide, ambos sin éxito terapéutico. Iniciado sotatol con reducción gradual y posterior normalización de FC fetal. El parto ocurrió a término, nació bien y evolucionó con taquicardia persistente. El electrocardiograma realizado demostró onda P con morfología de ritmo sinusal. Las posibles causas de taquicardia sinusal se eliminaron, confirmando así el diagnóstico señalado. Comentarios: El autor refuerza la importancia de la ecocardiografía fetal transvaginal para el diagnóstico y tratamiento precoz de arritmias fetales, evitando complicaciones

Fetal tricuspid valve Doppler at 11-13 weeks and 6 days: reference values and reproducibility.

OBJECTIVE: To determine normal blood flow velocities across the fetal tricuspid valve (TV) at 11-13 weeks and 6 days of gestation and to examine the reproducibility of these measurements. METHODS: A prospective study involving 166 normal singleton pregnancies examined at 11-13 weeks and 6 days was carried out. Descriptive analysis of E- and A-waves' maximum velocities, E/A ratio, duration of the cardiac cycle (C) and diastole (D) and D/C ratio were calculated. Intraobserver and interobserver agreement analysis was performed in a subgroup of 12 cases. RESULTS: Average ( +/- SD) flow velocities were: E-wave, 25.0 ( +/- 4.6) cm/s; A-wave, 42.9 ( +/- 5.9) cm/s; E/A, 0.58 ( +/- 0.07); cardiac cycle, 390 ( +/- 21.1) ms; diastole, 147 ( +/- 18) ms and D/C, 0.38 ( +/- 0.04). Significant correlation was observed between all parameters (except A-wave) and gestational age but not with nuchal translucency (NT). Intraclass correlation coefficients (interobserver, intraobsever examiner 1 and intraobserver examiner 2) were: E-wave, 0.53, 0.53 and 0.64; A-wave, 0.45, 0.46 and 0.49; cardiac cycle, 0.70, 0.79 and 0.84 and diastole, 0.63, 0.85 and 0.82, respectively. CONCLUSIONS: The present study establishes normal Doppler parameters for blood flow across the TV at 11-13 weeks and 6 days and demonstrates that these parameters do not correlate with NT measurement and have good/moderate reproducibility.

Papel da serotonina no desenvolvimento cardíaco / The role of serotonin in the heart development

A serotonina (5-HT), além de sua ação como neurotransmissor, participa do desenvolvimento do organismo. Durante o desenvolvimento do coração. agonistas e antagonistas serotonimérgicos podem provocar alterações morfogenéticas nas células desse órgão. A serotonina também atua como sinalizador morfogenético tipo dose-dependente, durante a formação do coração. No presente trabalho foi feita uma revisão da participação da serotonina no desenvolvimento cardíaco.

Comparison between right and left ventricular myocardia during the human fetal period. Stereological evaluation.

PURPOSE: To develop a stereological comparison between right (RV) and left ventricle (LV) myocardium during the third human gestational trimester. METHODS: Five human fetal hearts of the third trimester provided representative samples of 5 RV myocardium and 4 LV myocardium. The material was fixed in 10% buffered formaldehyde, and processed through routine methods. Fifteen microscopic fields were randomly chosen and counted in each ventricular myocardium using an "M-42" test system. The following stereological parameters were assessed: Vv (%), Lv (micron 2), Sv (micron 2/micron 3), Vp (micron 3), Nv (1/mm3) and total N. RESULTS: No significant difference between the stereological parameters of the myocardial structures assessed was evidenced, when comparing RV and LV. CONCLUSION: Right and left human ventricular myocardium are very similar during the fetal period at least in regard to their structural aspects.

[Fetal human myocardium. Proliferation of the myocytes and development of the cardiac interstitium in the last two gestational trimesters]. / Miocárdio fetal humano. Proliferação do miócito e desenvolvimento do interstício cardíaco nos dois últimos trimestres gestacionais.

PURPOSE: To determine prenatal myocardial quantitative changes by using stereology. METHODS: Twenty-six human fetuses were studied (16 in the 2nd trimester and 10 in the 3rd trimester). The hearts were dissected, weighted, fixed in the Bouin's solution for 12 h, embedded in paraplast, sectioned and stained by HE and trichrome of Gomori. Ten random microscopic fields were analyzed by heart. The following parameters were studied: Vv[myocyte] and Vv[interstitium] (%) (the volume densities of the cardiac myocyte and interstitium), and Nv[myocyte] (1/mm3) (the numerical density of the cardiac myocytes) by the dissector method. The total number of myocytes (N[myocyte]) and the mean volume of the myocytes (V[myocyte]) were also determined. The differences were tested by the Mann-Whitney non-parametric test. RESULTS: The cardiac weight increased of 1.95 to 9.1 g, the Vv[myocyte] decreased from 85.18 to 77.78% and the Vv[interstitium] increased from 14.83 to 22.22%. The Nv[myocyte] decreased from 68.86 x 10(4) to 57.40 x 10(4)/mm3. The V[myocyte] increased from 1214.38 to 1412.31 microns3 and the N[myocyte] increased from 1.36 x 10(9) to 5.06 x 10(9) myocytes. These differences were statistically significant (p < 0.05). CONCLUSION: These results suggest the development of the myocardium at the end of the fetal human period as being mainly hypertrophic to the myocyte and the cardiac interstitium.

Miocárdio fetal humano. Proliferação do miócito e desenvolvimento do interstício cardíaco nos dois últimos trimestres gestacionais / Fetal Human Myocardium. Proliferation of the Myocytes and Development of the Cardiac Interstitium in the Last Two Gestational Trimesters

PURPOSE: To determine prenatal myocardial quantitative changes by using stereology. METHODS: Twenty-six human fetuses were studied (16 in the 2nd trimester and 10 in the 3rd trimester). The hearts were dissected, weighted, fixed in the Bouin's solution for 12 h, embedded in paraplast, sectioned and stained by HE and trichrome of Gomori. Ten random microscopic fields were analyzed by heart. The following parameters were studied: Vv[myocyte] and Vv[interstitium] () (the volume densities of the cardiac myocyte and interstitium), and Nv[myocyte] (1/mm3) (the numerical density of the cardiac myocytes) by the dissector method. The total number of myocytes (N[myocyte]) and the mean volume of the myocytes (V[myocyte]) were also determined. The differences were tested by the Mann-Whitney non-parametric test. RESULTS: The cardiac weight increased of 1.95 to 9.1 g, the Vv[myocyte] decreased from 85.18 to 77.78and the Vv[interstitium] increased from 14.83 to 22.22. The Nv[myocyte] decreased from 68.86 x 10(4) to 57.40 x 10(4)/mm3. The V[myocyte] increased from 1214.38 to 1412.31 microns3 and the N[myocyte] increased from 1.36 x 10(9) to 5.06 x 10(9) myocytes. These differences were statistically significant (p < 0.05). CONCLUSION: These results suggest the development of the myocardium at the end of the fetal human period as being mainly hypertrophic to the myocyte and the cardiac interstitium.

[The development of cardiac function and its relation to metabolism during the perinatal period]. / Desarrollo de la función cardíaca y su relación con el metabolismo durante el periodo perinatal.

Several aspects of heart development are reviewed such as development of excitability and electrical and mechanical activity of the heart. Special emphasis is made upon metabolic changes during heart development and its possible consequences on electrical and mechanical activity.

Growth allometry of the myocardium in human embryos (from stages 15 to 23).

The relative growth of the myocardium was studied in 27 staged human embryos (Carnegie stages). The volume of the myocardium was determined for each embryo according to Cavalieri's principle (by using point-counting planimetry to determine the area of the profiles of the myocardium). The volume of the myocardium (variable Y) was correlated to embryonic crown-rump length (variable X in millimeters) and age (in days). The bivariate allometric equation was used as Y = aXb. The scatterplot was discontinuous, presenting two trends during the postsomitic period. The first part was composed of embryos staged from stages 15 to 20, and the second part by embryos staged from stages 21 to 23. The breakpoint between these different trends was found at the level of stage 20 (embryo of 22 mm in crown-rump length and age nearly of 52 days). From stages 15 to 20, the growth rate of the myocardium was allometrically negative. On the other hand, from stages 21 to 23 this growth rate was moderately allometrically positive. These differences in growth of the myocardium were analyzed and, at least partially, might be due to the functional circulatory increase in the peripheral vascular bed in correlation to the cardiac hemodynamic demand required at the end of the embryonic period proper.

[Human cardiac development: total volumetric increase of the heart, ventricular myocardium and endocardial cushions during the embryonic period]. / Desenvolvimento cardíaco humano: aumento volumétrico total do coração, do miocárdio ventricular e dos coxins endocárdicos durante o período embrionário.

PURPOSE: To compare the volumetric growth of the whole heart (WH), ventricular myocardium (VM), and endocardial cushions (EC) among each other and in relation to the growth of the embryo. PATIENTS AND METHODS: Collection of human embryos serially sectioned and stained (27 embryos) in post-somitic period. The volumes of WH, VM and EC were morphometrically determined and statistically correlated to the embryo's crown-rump length (C-R) by using the allometric equation Y = a chi b. RESULTS: The cardiac growth, and the growth of the VM and EC, presented significant (p less than 0.01) but allometically negative correlations in relation to C-R length. It indicates that cardiac changes in shape are more pronounced than in size. However, relative to the heart itself VM is the component that presents greater volumetric increase during the second month of gestation. EC decreases and end the embryonic period proper with less of 3% of the cardiac volume. CONCLUSION: Our quantitative results agree with more recent morphological studies which consider EC with small significance in valves and septa development, probably functioning more as a plastic component than in genesis of cardiac structures. On the contrary some lack in growth of the VM should disturb deeply cardiac development.