Magnetic resonance imaging of fetal heart: anatomical and pathological findings.

Congenital heart disease is one of the most frequent prenatal malformation representing an incidence of 5/1000 live births; moreover, it represents the first cause of death in the first year of life. There is a wide range of severity in congenital heart malformations from lesions which require no treatment such as small ventricular septal defects, to lesions which can only be treated with palliative surgery such as hypoplastic left heart syndrome. A good prenatal examination acquires great importance in order to formulate an early diagnosis and improve pregnancy management. Nowadays, echocardiography still represents the gold standard examination for fetal heart disease. However, especially when preliminary ultrasound is inconclusive, fetal MRI is considered as a third-level imaging modality. Preliminary experiences have demonstrated the validity of this reporting a diagnostic accuracy of 79%. Our article aims to outline feasibility of fetal MRI in the anatomic evaluation, the common indication to fetal MRI, its role in the characterization of congenital heart defects, and at last its main limitations.

Matrix array transducer for the examination of fetal heart.

The X6-1 xmatrix array transducer allows a completely new approach to the diagnostic ultrasound: it permits visualization of fetal heart in real time, without the need for gating, and it is unaffected by motion artefacts. It is obtained in real time, without any spatial reconstruction. The authors compared this technology with the traditional one in two case reports: a diagnostic doubt of small muscular ventricular septal defect was solved using this new technique; a diagnosis of complete atrioventricular septal defect was confirmed. Three-dimensional real-time imaging would seem very precise in the study of fetal heart: the defects were fully visualized from any angulations. This new technology is promising but from the authors' limited experience, there is no evidence to use it in routine practice. It should be very useful to commence a prospective study on fetuses at risk while testing the superiority of this technique.

Fetal MRI of the cardiovascular system: role of steady-state free precession sequences for the evaluation of normal and pathological appearances.

PURPOSE: This study aimed to evaluate the feasibility of fetal magnetic resonance imaging (MRI) with steady-state free precession (SSFP) sequences to visualise the normal and pathological appearances of the cardiovascular system. MATERIALS AND METHODS: This is a prospective observational study of 83 pregnant women who underwent fetal cardiac MRI: 43 patients (cases) had echocardiographic suspicion of congenital heart disease; 40 patients (controls) did not. Fetal cardiac MRI consisted of a static phase with multiplanar SSFP sequences and a dynamic phase with real-time SSFP sequences. Two radiologists evaluated the diagnostic quality of the SSFP images in both the controls and cases, the MRI morphological and functional features in the controls and the MRI signs of congenital heart disease in the cases. RESULTS: In both groups, SSFP sequences produced goodquality MR images and good visualisation of morphological features. Functional data appeared to be unavailable due to the current small temporal resolution and the technical impossibility of fetal cardiac triggering. MRI detected direct signs of congenital heart disease in 21 fetuses, indirect signs in six and both signs in 15. CONCLUSIONS: SSFP sequences are effective in demonstrating the morphological features of the cardiovascular system, whereas dynamic SSFP cine-MRI sequences may provide adjunctive albeit suboptimal functional information.

Assessment of congenital heart disease (CHD): is there a role for fetal magnetic resonance imaging (MRI)?

PURPOSE: To review our experience with fetal magnetic resonance imaging (MRI) to evaluate congenital heart disease (CHD). METHODS: We performed fetal MRI in 32 fetuses with an echocardiographically assessed CHD. Both direct and indirect signs of CHD were investigated. Direct signs considered were: morpho-volumetric abnormalities of the heart; malrotations; ventricular and atrial septal defects; anomalies of the origin, size and course of the great arteries. Indirect signs considered were: difficulty to recognize a "normal" anatomical structures in the reference projections; increase of the vascular size before a stenosis; hypertrophy of the papillary muscles; cardiomegaly and pericardial effusion. All MRI findings were compared with postnatal or autoptic findings. RESULTS: MRI allowed the CHD to be visualised by direct signs in 17 fetuses, indirect signs in 5 and both direct and indirect signs in 9 fetuses, excluding the prenatal echocardiographic suspect of hypoplastic left heart syndrome in 1 fetus. Postnatal echocardiograms or autoptic findings confirmed a normal heart in 1 fetus and CHD in 31 fetuses including a single cardiac anomaly or syndrome in 19 fetuses, 2 associated cardiac abnormalities in 11 and 3 cardiac anomalies in 1 fetus. However, in 2 fetuses MRI detected a ventricular septal defect successively disclosed by gold standard. CONCLUSIONS: MRI is a promising method for further assessment of the cardiovascular pathologies diagnosed by echocardiography, and may be a valuable tool in assessing associated extracardiac anomalies.

Colour Doppler echocardiography in children with group A streptococcal infection related tic disorders.

BACKGROUND & OBJECTIVES: A possible relationship has been suggested between tic disorders and streptococcal infections. To understand the complex relationship between streptococcal infections and neuropsychiatric disorders in children the present study was done on colour Doppler echocardiography of patients with possible post-streptococcal tic disorders. METHODS: The patients were 23 children (22 males, 1 female) affected by tic disorders, who at the time of the observation presented (or had presented in the past) signs of streptococcal infections temporally related to the onset or recrudescence of tic disorders. Echocardiographic examination and laboratory tests were performed on these children. RESULTS: In 4 cases a mild mitral insufficiency and in 8 cases a minimal mitral insufficiency was seen, all haemodynamically not significant. Follow up studies (up to 1 yr) showed the consistency and persistence of these findings. Of the 12 patients with echocardiographic abnormalities, 10 displayed very high anti streptolysin O (ASO) titres, 5 showed positive cultures for GAS and 9 had abnormal ESR, even if no significant differences were found in respect to patients with tics and normal echocardiography. INTERPRETATION & CONCLUSION: With the caution due to the design of study and to low number of patients, our data seem to indicate that the pathophysiology of GAS-infection related tic disorders is similar to that SC, at least in some cases.

Recombinant interferon alfa 2a in hepatic hemangiomatosis with congestive heart failure: a case report.

A 45-day-old patient was admitted with dyspnea, hepatomegaly, tachycardia, holosystolic murmur in the precordial region, and continuous murmur at the right hypochondrium. Four cutaneous angiomas were noted. Instrumental examinations revealed congestive heart failure and multiple focal lesions in the liver with typical features of hemangiomas. The therapy with subcutaneous interferon-alfa-2a (IFN-alpha) was administered for 12 months with progressive regression of cutaneous hemangiomas, liver lesions, and cardiological alterations. IFN-alpha therapy was effective without any significant adverse effects.

A Brownian simulation model of glutamate synaptic diffusion in the femtosecond time scale.

To gain a better understanding of the elementary unit of synaptic communication between hippocampal neurons, we simulated the release of glutamate from a single pre-synaptic vesicle and its diffusion into the synaptic cleft. Diffusion of glutamate was simulated by a Brownian model based on Langevin equations. The model was implemented for parallel computer simulation and tested under different conditions of glutamate release and different geometrical and physical characteristics of the synaptic cleft. All the tested parameters have shown to be important for the synaptic responses. The results show that the synaptic transmission efficacy is influenced by many different geometrical parameters and, as a consequence, the quality of the excitatory postsynaptic response can be very different in the same synapse. The variability in the quantal response found by several authors can also be explained by physical parameters other than by variations in the quantal content of the synaptic vesicle as proposed by these authors.

Human parvovirus B19 infection in infancy associated with acute and chronic lymphocytic myocarditis and high cytokine levels: report of 3 cases and review.

Human parvovirus B19 infection is occasionally associated with acute lymphocytic myocarditis (ALM). Three infants with B19 virus-associated ALM were followed up clinically, histologically, and immunovirologically. Each infant had B19 virus DNA in the blood or B19 virus-specific IgM antibodies. Two infants with postnatal infection recovered after immunosuppressive therapy. The third infant with possible prenatal infection developed chronic persistent myocarditis associated with persistent B19 virus DNA in the blood. All 3 infants had increased levels of interferon-gamma, tumor necrosis factor-alpha, and interleukins -6 and -8. Four newborns with congenital B19 virus infection and 4 infants and children who had postnatally acquired B19 virus infection without myocarditis all had normal levels of these cytokines. These observations suggest that B19 virus infection in infancy causes ALM in some infants and children.

A Brownian model of glutamate diffusion in excitatory synapses of hippocampus.

We simulated the diffusion of glutamate, following the release of a single vesicle from a pre-synaptic terminal, in the synaptic cleft by using a Brownian diffusion model based on Langevin equations. The synaptic concentration time course and the time course of quantal excitatory post-synaptic current have been analyzed. The results showed that they depend on the number of receptors located at post-synaptic membrane. Their time course are dependent both on the total number of the post-synaptic receptors and on the eccentricity of the pre-synaptic glutamate vesicle.

Computational experiments support a competitive function in the CA3 region of the hippocampus.

The comprehension of activities and functions of complex brain structures requires, among other things, information on simultaneous activities in several regions. Results reported in the literature using multi(micro/macro)electrode recordings or imaging techniques provide incomplete information due either to the small size and/or small number of investigated regions or to the poor spatiotemporal resolution, respectively. This is particularly true for the hippocampus and its subfields, and mathematical modeling and computer simulation have been used with the aim of obtaining information when this is lacking. Global activities in the CA3 field of the hippocampus, and in particular the genesis of theta rhythm and sharp waves, have been investigated here by a mathematical model formulated within the frame of a kinetic theory of neural systems. The model has taken into account data of experimental results both on different PSPs recorded in hippocampal neurons and on recurrent pyramidal collateral geometries. The computational 'experiments' to which the model was subjected suggest that the sharp waves arise through a selective and short block of the fast inhibitory neurons of CA3, produced by a medial septum inhibitory input, whereas the theta activity is produced by a durable, continuous inhibition of the slow inhibitory neurons. Information obtained also suggests that the recurrent pyramidal collaterals subserve a competitive, rather than a cooperative, organization. Based on these results a hypothesis on the possible functional organization of the CA3 field and of the entire hippocampus has been formulated. According to this hypothesis, the CA3 imposes a serial order on the flow of activity arriving at the hippocampus from the entorhinal cortex and from its connected polymodal cortical regions. This ordering permits cortical activities, arriving at CA3 on appropriate time intervals, to produce effects in regions of brain to which the CA3 projects. The competing cortical activities are lost.

Simulation of CA3 region of hippocampus by kinetic models.

The global activities of the hippocampal CA3 field which are induced by stimuli coming from entorhinal cortex have been investigated through computional experiments. The simulations are based on a mathematical model formulated within the frame of a kinetic theory of neural systems. To obtain a description closer to the real biological system, the kinetic model has been supplemented with elements describing the dynamics of neurotransmitters in synaptic clefts. Because high frequency activities occur in the CA3 field, elements for the description of receptor saturation and vesicle depletion phenomena have also been taken into account. The computational experiments show that CA3 model reacts to simulated stimuli from entorhinal sources activating the pyramidal neurons. This activity self-organizes within some limited areas, and spreads to the whole CA3 as a patterned reverberation of short period which requires both excitatory and inhibitory neural populations. The reverberating activity is then stopped by massive inhibition produced by slow-inhibitory neural population. The relationships between the parameters linked to the synaptic dynamic and the elements characterizing these patterns have been investigated.

Peculiarities of prevalence and morphology of congenital heart disease detected in utero.

Intrauterine echocardiography is changing our knowledge of congenital heart disease; cardiac defects diagnosed in utero have distinctive features of both prevalence and morphology when compared with those observed just after birth. We reviewed a series of 171 fetal heart conditions: 148 were diagnosed at intrauterine echocardiography, the diagnosis being verified at autopsy in 41, and 23 were observed at the postmortem only. Peculiarities of prevalence consisted in an excess of various defects, such as hypoplastic left heart syndrome, atrial isomerism, pulmonary atresia, and atrioventricular and atrial septal defects, and in a reduced number of completely different conditions, such as transposition of great arteries and aortic coarctation. Differences in prevalence have been attributed to difficulties in diagnosing some particular anomalies in utero, to the selection of pregnancies undergoing screening, and to the special intrauterine evidence of some heart defects. Peculiarities in morphology result from the coexistence with extracardiac malformations, from the changes in shape conditioned by fetal hemodynamics, and from the intrauterine evolution of the morphology of some malformations. We concluded that the knowledge of these characteristic traits was helpful to cardiac pathologists, pediatric cardiologists, and obstetricians, and allowed the re-evaluation of the role of hemodynamic factors in remodeling the malformed cardiovascular appara-tus.

Use of ICRF-187 for prevention of anthracycline cardiotoxicity in children: preliminary results.

The objective of this study is to assess the efficacy of ICRF-187 as a protective agent against anthracycline cardiotoxicity. Cardiac function was evaluated by echocardiography before and after each cycle of anthracycline chemotherapy associated with ICRF-187 and compared with that of a second group receiving anthracycline chemotherapy without ICRF-187. The patients were a group of 15 consecutive children affected with various types of solid tumors who were treated with either doxorubicin-daunomycin or epirubicin (average doses 340 and 280 mg/m2, respectively), and treatment was associated with ICRF-187. A second group of 15 consecutive children affected with different malignancies were simultaneously treated with either doxorubicin-daunomycin or epirubicin (average doses 309 and 270 mg/m2, respectively), but without ICRF-187 association. None of the patients treated with anthracyclines and ICRF-187 association showed abnormalities on echocardiographic examination. In the second group of patients treated with anthracyclines but without ICRF-187 association, we observed a decrease in the left ventricular ejection fraction to < 55% and a decrease in the left ventricular fractional shortening to < 28% in two patients (13.3%). One of these (6.6%) showed a dilatative cardiomyopathy. Both groups of patients were treated with low doses of anthracyclines. Although this study was not randomized, in patients without ICRF-87 cardioprotection, there was a trend for a worse evolution with one case of clinical cardiomyopathy as well as subclinical cardiac abnormalities.

[Prevalence of congenital cardiopathies among newborn infants in a department of pediatric cardiology]. / Prevalenza delle cardiopatie congenite in età neonatale in un reparto di cardiologia pediatrica.

This study consists of a prevalence congenital heart disease (CHD) registered in the Pediatric Cardiology Department of Umberto I General Hospital in Rome between January 1st 1992 and December 31-th 1993. Cases recorded in this period have been taken part of a larger study called Italian Multicentric Study for recording and follow-up of congenital heart disease (IMS-CHD); the purpose is to determine the prevalence of CHD in Italy and discover the outcome of affected children. In this duration, 187 new cases have been recorded, in which 63.6% had a single defect while 36.4% had multiple defects. These isolated defects were most frequently occurred (51.9%) following the stenosis of the pulmonary artery (15.5% and the defects of the interatrial septum (15%).

[Anatomo-clinical correlations of cardiopathies diagnosed during fetal life: analysis of 110 cases of cardiopathies]. / Correlazioni anatomo-cliniche delle cardiopatie diagnosticate durante la vita fetale: analisi di una casistica di 110 cardiopatie.

BACKGROUND: Fetal echocardiography has achieved high sensibility and specificity rates and it has become a reliable tool to detect intra-uterine congenital heart defects. OBJECTIVES: The purpose of the present study was to clarify the potential of anatomo-clinical correlation in fetal echocardiography not only for diagnosing heart defects, but also for understanding and following their morphogenesis and natural history in utero. METHODS: Nine hundred pregnancies, referred by several first-level centers, have been followed up from the sixteenth week to birth, and the newborn baby has been studied, too. In case of either voluntary abortion, or intra-uterine or neonatal death, a post-mortem examination was performed whenever possible. RESULTS: Since 1982, 110 fetal heart defects have been detected: 94 were diagnosed by means of fetal echocardiography (in 21/94 an autopsy was carried out) and 16 were directly observed at the post-mortem (spontaneous or voluntary abortions not previously referred). The heart defects most commonly observed were the atrioventricular (14.5%), ventricular (9.0%), and atrial (7.2%) septal defects, the absent left atrioventricular connection (8.1%), and atrial isomerism (6.3%). The congenital heart defects diagnosed in utero vary from those observed in the newborn and infants in terms of distribution (because of difficulties in diagnosis, selection of pregnancies, and differences in manifestation) and morphology (because of the coexistence with other extracardiac malformations, the changes due to altered fetal hemodynamics, and the intrauterine evolution of the morphology of cardiac defects). CONCLUSIONS: Heart defects observed in utero have a peculiar prevalence and a different morphology in respect to their infantile counterparts and can be followed in their morphologic evolution.

Regression of post-Fontan protein-losing enteropathy. After surgical correction of hemodynamic faults other than high right atrial pressure.

We describe a case of protein-losing enteropathy after a Fontan operation, in the absence of high right atrial pressure. Although partial regression of protein-losing enteropathy was obtained with high doses of cortisone, complete resolution of the phenomenon was accomplished only after surgical closure of a left-to-right shunt through the pulmonary valve.

Myocardial scintigraphy with 99mTc-sestamibi in children with Kawasaki disease.

Kawasaki disease (KD) is a systemic vasculitis syndrome of early childhood. It involves particularly the coronary arteries and may cause aneurysms and thrombotic occlusions. Echocardiography is the most useful method of detecting coronary aneurysms. Nevertheless, obstructive lesions are difficult to evaluate and often need invasive coronary angiography. An important feature of this disease is the possibility of finding coronary pathology several years after the onset. This characteristic makes KD an important cause of coronary artery disease (CAD) in young adults. Thus patients with KD and previously diseased coronary arteries should be kept under long-term control. However, coronary angiography is invasive and cannot be performed repeatedly, especially in young patients. As an alternative, thallium 201 scintigraphy has been employed, but its low-energy photons are suboptimal for standard gamma-camera imaging, particularly in children aged less than three years. To verify the usefulness of a noninvasive assessment of myocardial perfusion, the authors used rest and dipyridamole 99mTc-Sestamibi scan in 15 children (ranging from one to six years of age) with Kawasaki's cardiac involvement. Coronary aneurysms have been demonstrated by echocardiography in 12 patients; 8 patients were also submitted to cardiac catheterization. The sensitivity of 99mTc-Sestamibi imaging for detection of overall coronary lesions was 88% and the specificity was 93%. These data suggest that rest/dipyridamole 99mTc-Sestamibi scintigraphy is an accurate and noninvasive method for the detection and follow-up of Kawasaki's cardiac damage even in patients aged one year.

Prenatal echocardiographic diagnosis of right atrial isomerism.

A prenatal diagnosis of right atrial isomerism is often inferred through the recognition of a constellation of cardiac anomalies on the four-chamber view or by the detection of visceral heterotaxy and asplenia. However, the actual occurrence of discordance between the arrangement of the atria and thoracic and abdominal organs makes the identification of the morphology of both atrial appendages the only reliable way to make a final diagnosis of atrial isomerism. Three cases of right atrial isomerism with visceral heterotaxy and a complex cardiac defect, diagnosed in utero by cross-sectional and colour flow Doppler echocardiography, are reported. In all the patients, the right atrial isomerism was associated with an atrioventricular septal defect, a single aortic outlet from the right ventricle, and total anomalous venous return. The diagnosis of right atrial isomerism, always confirmed by neonatal re-evaluation and/or by post-mortem examination, was made through identifying two pyramidal atrial appendages in an echocardiographic transverse plane at the level of the atria and of the origin of the great arteries. This report demonstrates that a final intrauterine diagnosis of atrial isomerism is possible, whatever the visceral situs is.