A small interventional device to occlude persistently patent ductus arteriosus in neonates: evaluation in piglets.

OBJECTIVES: We attempted to evaluate the efficacy and tissue reaction of a new miniature interventional ductal occlusion device in neonatal pigs. BACKGROUND: A variety of devices are used to close persistent ductus arteriosus (PDA) by interventional measures. Because of the size of these devices, they have not been applied to term or preterm neonates. Newborn piglets are comparable in size and fragility to human term and preterm neonates. METHODS: Memory-shaped double-cone stainless steel coils were mounted on a titanium-nickel core wire. A snap-in mechanism attaches the coil to the delivery wire, allowing intravascular coil retrieval and repositioning. The system was placed through a 3F Teflon catheter. Two piglet models of PDA were used: 1) ductal patency maintained by stents (n = 6), and 2) ductal patency produced by angioplasty (n = 7) to avoid stent-coil interaction. RESULTS: Placement of the coils within the PDA was possible in all piglets. Before final detachment, the coils were retrieved or repositioned, or both, up to eight times. In all but two piglets the ductus was closed within 1 h of the procedure. The coils were never dislocated and caused no infections or relevant aortic and pulmonary artery obstruction (95% confidence interval for missing complications [0 of 13] extends to 23%). Histologic and electron microscopic studies revealed endothelial coverage of the implants and histiocytic reaction but no local or systemic inflammation or erosion of the implant. CONCLUSIONS: The device was effective in experimental models of PDA. The information obtained warrants initial trials of the device in neonates.

Surgical repair of aorto-right ventricular tunnel in an infant.

A rare case of aorta to right ventricle tunnel with associated pulmonary stenosis was corrected on cardiopulmonary bypass in a 3-month-old infant. Both the aortic and ventricular openings were closed with a patch. Although the repair was successful and the child was discharged from the hospital, septicemia developed and she died later. Early repair of this defect is recommended.

Diagnosis and follow-up of congenital heart disease in children with the use of two-dimensional Doppler echocardiography.

Two-dimensional echocardiography (2D) represents a major advance in non-invasive diagnosis of congenital heart disease (CHD) in children. Nevertheless it has diagnostic limitations in nearly all kinds of heart lesions. These can be overcome for the most part by integration of a pulsed Doppler system. This may be called two-dimensional Doppler echocardiography (2DD). Hereby blood flow information is added to the 2D image. Some common types of CHD including ventricular and atrial septal defects, persistent ductus arteriosus, pulmonic stenosis and coarctation are described with their typical 2DD findings. Non-invasive follow up of children with CHD and early recognition of typical complications can be achieved reliably using 2DD. Future prospects consist in a more quantitative diagnostic application of 2DD.

Fetal complete heart block: antenatal diagnosis, significance and management.

Complete heart block was diagnosed prenatally in 21 fetuses. Associated structural cardiac defects were present in 18 fetuses, in particular complete atrioventricular canal with atrial isomerism (5 cases), and 'corrected' transposition of the great arteries (4 cases). Maternal systemic lupus erythematosus was proved in only one case. In 11 fetuses, intra-uterine congestive heart failure with the signs of non-immune hydrops fetalis occurred. In all 11 fetuses, the hydrops was associated with a cardiac defect, in particular complete atrioventricular canal with atrial isomerism in 5 cases. A review of the literature confirms that only the association of complete heart block and cardiac malformation can cause intra-uterine congestive heart failure, whereas in the case of fetal complete heart block without cardiac malformation or with prenatally hemodynamically insignificant cardiac malformation, congestive heart failure is rare. Only 30% of newborns with complete heart block have associated cardiac malformations. In our series, however, 86% of the fetuses with complete heart block had cardiac malformations. The most important reason for this percentage discrepancy is that almost all fetuses with associated severe cardiac defects, in particular atrioventricular canal defects, develop heart failure which frequently results in prenatal death. Thus, fetal deaths are not included in pediatric statistics. Nevertheless, fetuses with isolated complete heart block generally do not develop heart failure and in almost all of the cases are born alive.

Flow analysis in the pulmonary trunc in fetuses with tetralogy of Fallot by colour Doppler flow mapping; two case reports.

Prenatal diagnosis of tetralogy of Fallot by two-dimensional echocardiography, which is based on demonstration of a ventricular septal defect and a large overriding aorta, is difficult. In the majority of cases the main pulmonary artery is small. In utero, there is no pathologically increased degree of the physiological right-ventricular hypertrophy. Colour Doppler flow mapping of reverse flow from the descending aorta via the ductus arteriosus into the main pulmonary artery is easily demonstrated, and provides an indirect sign of severe right-ventricular outlet obstruction. The technique also differentiates between pulmonary stenosis and atresia; the stenotic jet, even small, is identified by demonstration of high velocities and turbulences in the main pulmonary artery.

Color Doppler echocardiographic evaluation of tricuspid regurgitation and systolic pulmonary artery pressure in the full-term and preterm newborn.

Color Doppler echocardiography of tricuspid valve regurgitation (TR) is a valid, noninvasive method of determining systolic pulmonary artery pressure (SPAP). In a prospective study the authors examined 56 healthy full-term newborns (group I), 36 healthy preterm newborns (group II), and 10 preterm newborns with severe respiratory distress syndrome requiring surfactant replacement therapy (group III). Doppler studies were repeated until the transtricuspid gradient was < 20 mm Hg. In 83.3% of children a reproducible spectral curve was recorded at least once. The authors estimated the transtricuspid gradient delta p (RV-RA) by using the modified Bernoulli equation. Within the first twenty-four hours delta p (RV-RA) was < 20 mm Hg in 72.7%, 50%, and 25% of children with measurable TR in groups I, II, and III, respectively, increasing to 91.1%, 78.6%, and 55.6% within forty-eight hours. There was no significant correlation between SPAP and gestational age, birth weight, mode of delivery, and ductal closing time. Continuous holosystolic envelope tracing of TR was recorded in 16.6%. In these patients delta p (RV-RA) was measured markedly higher (mean of 30.1 mm Hg) than in the others (mean 17.3 mm Hg). The authors conclude that there is a high prevalence of TR in neonates, which allows estimation of SPAP in > 80% of newborns without considerable impairment. Normalization of SPAP takes place within four days in most patients, but there is a delay in preterm infants with severe respiratory distress syndrome.

[Color Doppler echocardiography--possibilities and limits of a new procedure]. / Farb-Doppler-Echokardiographie--Möglichkeiten und Grenzen eines neuen Verfahrens.

Color-flow-mapping (CFM) has added a new dimension to the echocardiographic diagnosis of heart disease. Typical characteristics of blood flow, i.e., flow direction, relative velocities, and degree of "turbulence" in the cardiovascular system are displayed within the two-dimensional echocardiographic image. This gives hitherto unknown insights into the physiology of blood flow velocity profiles. Pathological flow patterns in heart disease are easily recognizable and their display within the CFM image allows a straightforward diagnosis of the underlying heart disease. This feature is especially valuable in the diagnosis of heart disease with shunt and in valvular regurgitations in children, as well as in adults. CFM is also useful for optimal angulation in the assessment of gradients using the simplified Bernouilli equation. It is characterized by a remarkably high diagnostic sensitivity and specificity. However, quantitation of heart disease causing volume load is still limited by the lack of standardization in the process of color encoding of the Doppler data. Digital flow mapping (DFM) offers an opportunity for the standardized sampling of Doppler data offering development of an established modality for color encoding. Moreover, DFM offers the opportunity for calculation of angle-corrected velocities. Here a new non-invasive way for a reliable calculation of cardiac output may present itself.

[Diagnosis of congenital heart defects using color-coded Doppler echocardiography]. / Diagnostik angeborener Herzfehler mittels farbkodierter Doppler-Echokardiographie.

Color Doppler echocardiography (CDE) enables visualization of blood flow and of cardiac morphology within color coded two-dimensional images. The diagnostic usefulness of this method in pediatric cardiology has been analyzed based on studies performed in 2414 children. Normal cardiac findings were seen in 769 patients according to the clinical and echocardiographic examinations. Normal diastolic inflow into the ventricles in the apical four-chamber-view is characterized by a similar distribution of the color spectrum across the inflow tracts, blood flowing on the two sides of the heart is completely separated from each other. Normal systolic outflow imaged from parasternal position shows an increase in velocity in the outflow tract passing through the semilunar valves without any change in flow patterns. Heart disease was present in 1645 patients, simple cardiac defects were found in 1473 cases and complex heart disease in 172 cases. Shunt lesions are detectable by the demonstration of blood flow in regions where normally no flow is detectable, flow velocities being pathologically increased in many cases. Diagnostic sensitivity and specificity of CDE as compared to invasive procedures is between 96 and 98%. In left-to-right shunting the shunt flow can be followed into the right-sided cardiovascular regions where its extent is a measure for the size of the shunt as indicated by initial results. In ventricular septal defects, bidirectional shunting is indicative of a rise in pressure in the right ventricle and can be reliably detected with the use of CDE. In valvular stenoses high flow velocities are found in the appropriate time which are associated with turbulence and poststenotic eddies.(ABSTRACT TRUNCATED AT 250 WORDS)

Intrauterine therapy of fetal tachyarrhythmias: intraperitoneal administration of antiarrhythmic drugs to the fetus in fetal tachyarrhythmias with severe hydrops fetalis.

In cases of fetal tachyarrhythmia with congestive heart failure accompanied by signs of non-immune hydrops fetalis, the transplacental treatment of the fetus with antiarrhythmic agents by administration of drugs to the mother is only rarely successful. In the two cases reported, the cardioversion of a supraventricular tachycardia to a sinus rhythm or a constant 2:1 AV conduction block to a 1:1 AV conduction with atrial flutter could only be achieved after additional antiarrhythmic treatment directly administered to the fetus using ultrasound guidance. Drugs used include: beta-methyldigoxin, verapamil, propafenon, and they were administered according to the dosing amounts for intravascular injections. This was carried out 12 times in case 1 by the intraperitoneal route into the fetal ascites and twice in case 2. This led in both cases to varying durations of a sustained sinus rhythm after 5-15 minutes. This technically relatively simple procedure affords the option of rapidly achieving high concentrations, even when antiarrhythmic agents are administered which do not adequately cross the placenta. This direct treatment is indicated in cases of tachyarrhythmia with advanced signs of non-immune hydrops fetalis as a supplement to the high-dose transplacental therapy using antiarrhythmic agents.

[2-dimensional color-coded fetal Doppler echocardiography--its value in prenatal diagnosis]. / Zweidimensionale farbkodierte fetale Doppler-Echokardiographie--ihr Stellenwert in der pränatalen Diagnostik.

105 fetuses between 16 and 38 weeks of gestation were studied by fetal echocardiography using color-coded two-dimensional Doppler-echocardiography (2-DDE). Two-dimensional, M-mode, and spectral-Doppler analyses were also performed. In 11 fetuses, structural and/or functional abnormalities were detected. Abnormalities were correctly excluded in all other fetuses. The advantages of the 2-DDE are, in particular: rapid screening for flow abnormalities in the fetal heart and, thus, shortening of the Doppler-examination time; furthermore, a rapid diagnosis of valvular regurgitation, valvular stenosis and abnormal shunting of blood across the interatrial and interventricular septa; the diagnosis of complex congenital heart defects is facilitated by and, in certain case, only possible using 2-DDE.

Longitudinal study in 18 cases of fetal supraventricular tachycardia: Doppler echocardiographic findings and pathophysiologic implications.

A longitudinal study was performed in nine nonhydropic and nine hydropic fetuses with supraventricular tachycardia (SVT). First, because of a lack of reference methods in utero, the validity of spatial (length and area) and temporal parameters for semiquantitative grading of atrioventricular (AV) valve regurgitation by color Doppler flow mapping and M-Q mode imaging was evaluated by a longitudinal intraindividual study before and after drug-induced cardioversion to sinus rhythm and by correlation with the severity of hydrops and the time required for complete remission of hydrops. Second, with the demonstration of AV valve incompetence and changes in venous blood flow velocity wave forms, new data were collected concerning chronic SVT in the fetus. AV valve incompetence occurred in eight fetuses: during SVT only in three severely hydropic fetuses, during sinus rhythm in one nonhydropic fetus, and in seven hydropic fetuses including those previously mentioned, where AV incompetence outlasted tachycardia. The length and area of the regurgitant jet as imaged by color Doppler flow mapping and the temporal duration of regurgitation in relation to the systolic phase as measured by M-Q mode continuously diminished intraindividually but with great interindividual differences in the time span required for complete remission, which ranged from 5 to 42 days. Pulsed-wave Doppler studies of blood flow in the inferior vena cava and left hepatic vein demonstrated normal biphasic forward flow with a systolic and a diastolic surge during sinus rhythm in all fetuses and in two instances also during SVT of 190 and 195 beats/min, respectively. In all cases a pulsatile reversal of blood flow with systolic forward flow and diastolic reverse flow was observed during tachycardia greater than 220 beats/min. Thus the presence of functional AV valve incompetence as a result of annular enlargement seems to be a sign of SVT-induced "cardiomyopathy" during fetal life. AV valve incompetence during SVT was always associated with extremely severe hydrops and seemed to indicate the most severe degree of ventricular dysfunction, which could influence the selection of antiarrhythmic drugs. After termination of SVT, severe AV valve insufficiencies also occurred in other cases of hydrops, probably because of the markedly increased diastolic filling distending the already enlarged annular ring. The observed great interindividual differences in time required for disappearance of AV valve incompetence and hydrops could be explained by a different state of progression of tachycardia-induced "cardiomyopathy" at the time of drug-induced cardioversion.(ABSTRACT TRUNCATED AT 400 WORDS)

[Augmented reality in echocardiography. A new method of computer-assisted training and image processing using virtual and real three-dimensional data sets]. / Augmented Reality in der Echokardiographie--Eine neue Methode der computergestützten Ausbildung und Bildbearbeitung durch virtuelle und reale dreidimensionale Datensätze.

Augmented reality (AR) applications link real with virtual image data, in order to increase their information content. In medicine they are especially useful for education and for supporting the interpretation of three-dimensional (3D) image data. Simulators are used to train risky or expensive procedures. In the AR application EchoCom2 a 3D surface model of the human heart is linked with echocardiographic volume data sets. The 3D echocardiographic data sets are registered with the heart model to synchronize it's temporal and spatial orientation. The heart model together with an animated ultrasound sector represents a reference scenario, which displays the currently selected cutting plane within the echocardiographic volume data set. Modifications of the cutting plane within the echocardiographic data are transferred simultaneously and in real time to the reference scenario. The AR application is used as a simulator to train two-dimensional echocardiographic examinations and as an orientation and navigation aid for the exploration of 3D echocardiographic data sets. Beginners in echocardiography have only a rudimentary conception of the spatial relationship between the actual ultrasound image and the 3D anatomy of the heart. They are unable to translate multiple two-dimensional slices into a coherent 3D mental image of the heart. In EchoCom2 the trainee can interactively explore the 3D heart model and the registered 3D echocardiographic data sets by the animated ultrasound sector, whose position is controlled by an electromagnetic orientation and position system (EPOS). The data from the EPOS are used to calculate the echocardiographic images that are analogue to the position of the animated ultrasound sector. EchoCom2 is also used to support the interpretation of 3D echocardiographic data sets. The analysis of 3D echocardiographic data has to be done during a post processing. Defining the exact position of a cutting plane within the volume is difficult due to the lack of a standardized representation, the independence of the cutting plane of any transducer position and the possibility to calculate an indefinite number of views. The simultaneous representation of the current cutting plane both in the volume data, and in the heart model enables the examiner ad hoc to recognize it's position and the visualized structures.

Acute mitral regurgitation due to chordal rupture in a patient with neonatal Marfan syndrome caused by a deletion in exon 29 of the FBN1 gene.

The neonatal Marfan syndrome is an autosomal dominantly inherited disease with an extremely poor prognosis. This report gives a clinical and echocardiographic description of an infant with a mutation in exon 29 of the fibrillin-1 gene (FBN1), a region in which this severe form of Marfan syndrome seems to cluster. The infant died at the age of 3 months due to severe acute mitral regurgitation leading to intractable heart failure.

[Non-invasive Doppler echocardiography assessment of right ventricular pressure in patients with ventricular septal defect]. / Nichtinvasive Doppler-echokardiographische Abschätzung des rechtsventrikulären Drucks bei Patienten mit Ventrikelseptumdefekt.

In patients with VSD right ventricular pressure can be determined noninvasivly by subtracting the VSD-gradient from the systolic blood pressure. Using a stand-alone continuous-wave Doppler the VSD-gradient may be underestimated due to a large angle theta caused by the various VSD locations and the often atypical VSD-jet directions. Therefore Color-Doppler was used to visualize the VSD-jet and to align (angle less than 15 degrees) the continuous-wave Doppler beam. 37 patients, who underwent catheterization were studied. By VSD-jet visualization 3 patients were correctly identified in whom the VSD gradient would have been underestimated due to a large angle 0. They were excluded from this study because of the resulting error. In the remaining 34 patients VSD-gradients up to 105 mmHg were measured. A good correlation was found between the noninvasively an invasively determined right ventricular pressures: r = 0.93; y = 1.06x -2.4. One source of error in this method is the difference between the maximal instantaneous and the peak to peak VSD-gradient. Differences of up to 39 mmHg were found when the maximal instantaneous gradient occurred either very early or very late in systole. In these cases the midsystolic gradient should be used. It is concluded that the presented method is easy to perform and permits a reliable noninvasive estimation of the right ventricular pressure in patients with VSD.

Prenatal diagnosis of a left ventricular aneurysm.

In a fetus with ventricular extrasystoles a congenital aneurysm of the left ventricle was diagnosed prenatally. At 32 weeks of gestation, echocardiography showed a large apical left ventricular aneurysm with a thin, hypokinetic wall. Congestive heart failure did not occur. Prenatal and postnatal examinations did not detect the aetiology of the aneurysm, but excluded the majority of possible causes. The 2-year-old child is now asymptomatic and normally developed. Neither medication nor surgical treatment have been necessary, except for antithrombotic prophylaxis with low-dose aspirin.

Fetal two-dimensional Doppler echocardiography (colour flow mapping) and its place in prenatal diagnosis.

One hundred and fifty fetuses between 16 and 38 weeks of gestation were studied by fetal echocardiography using colour-coded two-dimensional Doppler echocardiography. Two-dimensional, M-mode, and Doppler spectral analyses were also performed. In 14 fetuses, structural and/or functional abnormalities were detected. Abnormalities were correctly ruled out in all the other fetuses. The advantages of two-dimensional Doppler echocardiography are (1) rapid screening for flow abnormalities in the fetal heart, and thus shortening of the Doppler examination time; (2) rapid diagnosis of valvular regurgitation, valvular stenosis, and abnormal shunting of blood across the interatrial and interventricular septa; and (3) facilitation of the diagnosis of complex congenital heart defects which in certain cases is possible only by using two-dimensional Doppler echocardiography.

[2-dimensional color coded Doppler echocardiography of the fetus: physiologic and pathologic findings]. / Zweidimensionale farbkodierte Doppler-Echokardiographie des Feten: physiologische und pathologische Befunde.

The fetuses of 352 patients at between 16 and 38 weeks of gestation were studied by using two-dimensional Doppler echocardiography (2-DDE). In 32 fetuses, structural and/or functional abnormalities were detected. The advantages of 2-DDE are, in particular, rapid screening for flow abnormalities and, thus, shortening of the Doppler examination time. Further benefits include a rapid diagnosis of valvular regurgitation, valvular stenosis, and abnormal shunting of blood across the cardiac septa. The diagnosis of complex heart defects is facilitated by and, in certain cases, only possible at all using 2-DDE.

[Ventricular septal defect following cardiac trauma: closure with the Amplatzer Septal Occluder]

Ventricular septal defect following cardiac trauma: percutaneous closure with the Amplatzer septal occluder. HISTORY AND CLINICAL FINDINGS: A 36-year old roofer fell 8 m and suffered a severe polytrauma. A complicating pericardial tamponade was relieved as an emergency and myocardial fissure of the left ventricle about 1 cm in length sutured. 2 weeks later, a severe mitral insufficiency due to rupture of the papillary muscle occurred, that was cared by the implantation of a bioprosthesis. 6 weeks later dyspnoea and restricted physical capability were clinically impressive. INVESTIGATIONS AND DIAGNOSIS: Echocardiography demonstrated a posttraumatic muscular ventricular septal defect. Doppler echocardiography and heart catheterization showed a ventricular septal defect still restrictive with a left-to-right shunt (pulmonary-to-systemic flow ratio Qp/Qs 1.8:1). Under exercise, there was a significant increase in mean pulmonary arterial pressure from 27 to 60 mmHg. TREATMENT AND COURSE: The patient who had already been operated twice before was treated by the percutaneous occlusion of the ventricular septal defect from arterio- to venofemoral, a guide catheter was inserted transseptally into the left ventricle. An Amplatzer Septal Occluder, a self-expandable, self-centering wire-mesh double disc with a connecting central stent part, was loaded and then implanted in the ventricular septal defect. The intervention was controlled by fluoroscopy and echocardiography. Post intervention, only a trivial residual shunt was seen. The pumping efficacy of the left ventricle increased, in particular of the septal and apical segments. Clinically, the patient was markedly more load-bearing, the exercise-induced dyspnoea reduced. CONCLUSIONS: Following a cardiac trauma, various complications may occur that can manifest themselves clinically at two or more times. A posttraumatic ventricular septal defect of a patient already operated was successfully occluded by an Amplatzer Septal Occluder. Alongside established surgical methods, the non-operative implantation of new occlusion systems could mean an effective treatment option for muscular ventricular septal defects.

Color Doppler flow mapping of fetal heart.

Color Doppler flow mapping of fetal heart was performed in 582 fetuses between 16 and 38 weeks of gestation. Congenital heart diseases were excluded in 522 fetuses correctly. In 59 fetuses structural and/or functional cardiac abnormalities were diagnosed. In one fetus small multiple ventricular septal defects were missed. The most important additional information obtained by color Doppler flow mapping was: (1) Diagnosis of insufficiencies of atrioventricular valves; (2) Demonstration of turbulent high velocity jet in stenosis of semilunar valve; (3) Reverse flow in ascending aorta in atresia of aortic valves and on ductus arteriosus and main pulmonary artery in atresia of pulmonary valves; (4) Reverse perfusion of ductus arteriosus and main pulmonary artery as well as an antegrade turbulent high velocity jet in severe pulmonary stenosis as part of tetralogy of Fallot; (5) Bidirectional interventricular shunting of blood in ventricular septal defect. Color Doppler flow mapping allows rapid screening for flow abnormalities of the fetal heart. Exact localisation of sample volume by pulsed wave Doppler in area of abnormal flow pattern is possible, thus significantly reducing the Doppler examination time. The accuracy of prenatal diagnosis of congenital heart diseases is improved by application of color Doppler flow mapping, in particular in presence of complex cardiac defects.