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Biomedical subjects

I Hammerer

Publications and source records attributed to I Hammerer.

At least 19 recordsLinked to original sources

Balloon dilation for aortic recoarctation: morphology at the site of dilation and long-term efficacy.

OBJECTIVES: We undertook this study to assess the immediate and long-term outcome of balloon angioplasty performed for recurrent or residual coarctation of the aorta, and to assess the changes in the vessel wall caused by this procedure. METHODS: Clinical, echocardiographic, angiographic and hemodynamic data from 71 patients who underwent balloon angioplasty for recoarctation between January 1987 and January 1998 were analysed retrospectively. RESULTS: Angioplasty was performed after a median of 82.6 months (range 1.4 mo-20.9 y, mean 88.5 mo) following surgery for coarctation. Mean systolic pressure gradients were reduced from 27 +/- 15 mmHg to 11 +/- 11 mmHg after angioplasty (p < 0.0001). The mean diameter at the site of recoarctation increased from 5.5 +/- 2.5 to 7.5 +/- 2.7 mm (p < 0.0001). Outpouchings of contrast agents, indicating the disruption of the inner layers of the vessel wall, were defined as extravasations. They were observed in one-quarter of the angiograms performed immediately after the intervention. Immediate success of angioplasty was achieved in 71%, and persisted in 69% of patients during long-term follow up. The main determinant for immediate success was the age at the time of the procedure (p < 0.05), while the main determinant for long-term success was the increase achieved in diameter. Extravasations did not progress to aneurysms, neither acutely nor during echocardiographic follow-up studies. For further follow-up, more sensitive imaging techniques will be necessary to delineate the morphology of the site of extravasation observed immediately after angioplasty.

Adolescent↗

Conventional ventilation versus high-frequency oscillation: hemodynamic effects in newborn babies.

OBJECTIVE: We conducted a prospective study to assess the hemodynamic effects of conventional mechanical ventilation (CMV) compared with high-frequency oscillation (HFO) in newborn babies with respiratory distress syndrome. METHODS: A total of 18 consecutive term and preterm infants were examined by two-dimensional M-mode and pulsed Doppler echocardiography. RESULTS: Five patients had to be excluded, three of them because of increasing cardiovascular support after initiation of HFO. The remaining 13 infants (seven males, six females) had a median gestational age of 33 wks (range, 25-40) and a birth weight of 2350 g (range, 790-3600). Patients entered the study at 21 hrs (range, 5-69) of life, receiving total maintenance fluid of 90 mL/kg/day (range, 60-120). Five babies (38%) needed continuous inotropic support. HFO was used as a rescue therapy in infants who failed with CMV. In all 13 patients, HFO significantly impaired cardiac performance compared with CMV by decreasing aortic velocity-time integral: median, 10.2 cm (range, 6.0-14.6) vs. 8.3 cm (range, 5.3-12.4; p<.002); stroke volume: median, 3.8 mL (range, 1.6-6.8) vs. 3.2 mL (range, 1.3-5.9; p<.002); and cardiac index: 281 mL/min/kg of body weight (range, 177-579) vs. 200 mL/min/kg of body weight (range, 156-591; p<.002). Fractional shortening was also significantly reduced: median, 0.31% (range, 0.24-0.44) vs. 0.29% (range, 0.20-0.34; p<.01), because of a significantly smaller left ventricular diastolic diameter during HFO: median, 1.4 cm (range, 1.0-1.9) vs. 1.4 cm (range, 0.9-1.8; p<.05), with a median difference of -0.07 cm (range, -0.4-0.2). HFO also causes a significant decrease in heart rate-corrected left ventricular ejection time: median, 0.25 sec (range, 0.23-0.28) vs. 0.23 sec (range, 0.21-0.26; p < .02) and heart rate-corrected velocity of circumferential fiber shortening (Vcfc): median, 1.3 circ/sec (range, 1.0-1.6) vs. 1.2 circ/sec (range, 0.9-1.4; p<.05). Left ventricular end-systolic wall stress (LVESWS; g/cm2) remained stable. The correlation between Vcfc and LVESWS did not show any significance (CMV, r2 = .2; HFO, r2 = .09). The regression line between Vcfc and LVESWS showed a higher y-intercept and steeper slope during CMV than during HFO. Heart rate, mean arterial pressure, and left ventricular systolic diameter remained unchanged. CONCLUSIONS: In newborn babies, HFO significantly decreased left ventricular cardiac output caused by reduced left ventricular filling and HFO decreased contractility at higher mean airway pressures than with CMV.

Cardiac Output↗

Changes in left ventricular function in shocked newborns.

OBJECTIVE: To assess whether the change in cardiac output after volume replacement is due to elevation of stroke volume or heart rate and to determine the effect of mechanical ventilation on the hemodynamic situation. DESIGN: Prospective study. SETTING: A ten-bed neonatal intensive care unit (level III) at a university hospital. PATIENTS: 15 consecutive newborns with blood pressure below the 10th percentile related to age and weight. INTERVENTIONS: Volume replacement with Ringer's lactate 20 ml/kg body weight. MEASUREMENTS AND RESULTS: Before and after volume replacement, arterial pressure recordings, blood gas analysis, and an echocardiographic study were carried out. Left ventricular and aortic diameters were measured by the two-dimensional M-mode technique and velocity time integral of aortic flow by the pulsed color Doppler technique. From these data, stroke volume and cardiac output were calculated. Cardiac output (703 +/- 204 vs 826 +/- 166 ml/ min, p < 0.005) and cardiac index (267 +/- 69 vs 302 +/- 55 ml/min per kg body weight, p < 0.01) changed significantly due to an appreciable elevation in stroke volume (5.2 +/- 1.7 vs 5.8 +/- 1.7 ml, p < 0.05), whereas heart rate was unaltered (140 +/- 12 vs 142 +/- 20 beats/min; NS). The change in blood pressure (32 +/- 5 vs 38 +/- 8 mm Hg, p < 0.01) was also significant. Cardiac index before and after volume replacement showed a significant inverse correlation with the severity of respiratory disease expressed as alveolar-arterial oxygen difference (A-aDO2) (A-aDO2 vs cardiac index before volume replacement: r = -0.77, p < 0.001; after volume replacement: r = -0.73, p < 0.005) or oxygenation index (oxygenation index vs cardiac index before volume replacement: r = -0.73, p < 0.005; after volume replacement: r = -0.73, p < 0.005). Changes in left ventricular diastolic diameter, left ventricular systolic diameter, and fractional shortening were not significant. CONCLUSIONS: These results indicate that the major regulator of left ventricular output in newborns with hypovolemic or cardiogenic shock is stroke volume and not heart rate and that cardiac output depends on the severity of the respiratory disease.

Cardiac Output↗

Cardiac troponin T and creatine kinase MB mass concentrations in children receiving anthracycline chemotherapy.

Anthracyclines (doxorubicin, daunorubicin, and derivatives) are among the most effective antineoplastic drugs for pediatric cancer with dose-limiting acute and long-term cardiotoxicity. The exact mechanism of the development of cardiomyopathy is still not clear. Anthracyclines may induce subclinical acute myocardial injury leading to lysis of a limited number of myocytes. Alternatively, myocytes may experience a transient loss of cytoplasmic membrane integrity. Both conditions may lead to a transient efflux of small amounts of cytoplasmic enzymes and other proteins specific to the heart muscle fibers. To test these hypotheses we assayed plasma creatine kinase (CK) MB mass and cardiac specific troponin T (TnT). CKMB may be released even in case of reversible cell membrane injury, while prolonged elevation of TnT is the most sensitive and specific marker of limited myocardial necrosis. Thirty-five anthracycline-containing chemotherapy courses in 22 children with cancer were analyzed. CKMB mass and TnT concentrations were within the normal range in all children before anthracycline therapy. Within 72 hours from anthracycline therapy no increment of one of these two marker proteins was detected (ANOVA for repeated measures, P = 0.94 [TnT] and 0.25 [CKMB]). We conclude that only minimal if any acute necroses of cardiac myocytes occur after anthracycline therapy. Even membrane integrity appears to be maintained within the first 3 days after anthracycline therapy, in the absence of electrocardiographic or echocardiographic signs of acute cardiotoxicity.

Adolescent↗

Pulmonary sling: morphological findings. Pre- and postoperative course.

Pulmonary sling (PS) is a congenital condition in which the left pulmonary artery (LPA) arises from the right pulmonary artery (RPA), forming a sling around the trachea causing tracheal compression. The incidence is not so rare as initially thought. Symptoms of severe airway obstruction often begin in the newborn or young infant. Echo-colour-Doppler may reveal the PS but emphysema can mask the typical findings. Deviation of fluid-filled lungs may be detected prenatally. Chest radiographs show unusual air distribution, deviation of heart and mediastinum and altered tracheobronchial angles. Bronchography and bronchoscopy demonstrate the high incidence of associated tracheal anomalies such as cartilagenous rings and long tracheal stenosis. Anterior oesophageal indentation is not always seen in the oesophogram. Magnetic resonance imaging (MRI) and computed tomography (CT) reveal the PS, but cautious interpretation is necessary because of different levels of the anomalous LPA. PS and associated cardiovascular malformations can be clearly detected by angiography. Associated extrathoracic anomalies are common. Early diagnosis and therapy of PS is mandatory and consists of reimplantation of the LPA into the pulmonary trunk and division of the ligamentum arteriosum. The postoperative course may be cumbersome necessitating bronchological interventions. Tracheal resection may be necessary but restenosis is frequent. A one-stage repair has been proposed in such cases and was successfully done in a few reported cases. Relief of respiratory obstruction is often complete when there are no associated tracheobronchial anomalies. Late postoperative course is favourable but respiratory obstructive attacks may occur with decreasing incidence over time and tracheal growth.

Abnormalities, Multiple↗

Diagnosis of congenital pericardial defects, including a pathognomic sign for dangerous apical ventricular herniation, on magnetic resonance imaging.

OBJECTIVE: To establish criteria for the accurate diagnosis of different forms of left sided pericardial defects on magnetic resonance imaging. Early detection of a partial apical defect is essential as it is potentially fatal. DESIGN: Examination of four children with congenital pericardial defects by magnetic resonance imaging, the results being compared with the features on conventional chest radiography and echocardiography and with published data. RESULTS: Magnetic resonance imaging improved the ability to diagnose and distinguish between complete and partial left sided pericardial defects. A deep myocardial crease was visualised in a patient with apical pericardial defect, indicating the risk of a life threatening ventricular strangulation. A prominent left atrial appendage was, in contrast to many reports, not a reliable sign for partial left sided pericardial defect. CONCLUSIONS: The various forms of congenital left sided pericardial defects cannot reliably be diagnosed in plain chest radiographs or on echocardiography. Their diagnosis and the distinction between partial and complete defects, however, is of clinical importance and can be accomplished more confidently by magnetic resonance imaging.

Adolescent↗

[Balloon dilatation of postoperative and congenital aortic isthmus stenoses].

From July 1987 to December 1992, 52 patients underwent balloon-angioplasty of aortic coarctation at three units of pediatric cardiology in Austria (Graz = 35 patients, Innsbruck = 15 patients, and Vienna = 2 patients). 35 patients had postoperative and 17 had native coarctation. Mean age at intervention was 7 10/12 years with 2 patients under 1 year and 5 patients over 18 years old. The mean relation balloon diameter-coarctation diameter was 2.6 +/- 0.9. The blood pressure gradient between upper and lower extremities decreased from a mean of 44 +/- 16 mm Hg to 15 +/- 13 mm Hg (p < 0.0001). The diameter of the stenosed segment was increased from 5 +/- 3 mm to 8.5 +/- 3.5 mm (p < 0.0001). Native coarctation showed a significantly better result in respect to decrease of the gradient (36 +/- 12 mm Hg) than did postoperative coarctations (25 +/- 19 mm Hg) (p < 0.03). 13 patients did not respond adequately to angioplasty. 10 patients out of this group had tubular narrowings and belonged to the group of postoperative coarctations, whereas localized stenoses in native coarctations gave the best results. Localized wall irregularities were found in 4 patients with native coarctation. Balloon angioplasty of postoperative and native coarctations in childhood and adolescence is a secure and effective means of treatment and should be considered as therapy of first choice. The best results can be found in the group of the circumscript type of stenoses in native coarctation, whereas long and tubular stenoses in the group of postoperative coarctations give less satisfying results.

Adolescent↗

Capillary versus arterial plasma catecholamines as markers for sympatho-adrenal activity in infants.

In this study, we investigated whether capillary plasma catecholamines can be used as a suitable substitute for arterial catecholamines. Analysis was done radioenzymatically. Catecholamine concentrations were not different in arterial and simultaneously collected "arterialized" (warmed foot) capillary plasma obtained by heel-prick from 18 neonatal intensive care patients as assessed by linear regression analysis (correlation coefficient: 0.966 for noradrenaline; 0.894 for adrenaline; p less than 0.05) and by a Wilcoxon test [noradrenaline: 2.13 (0.61-10.47) versus 2.41 (1.05-10.23); adrenaline: 0.75 (0.16-1.70) versus 0.72 (0.10-1.37) nmol/L, median (range)]. However, "arterialization" of capillary blood is important; when blood was obtained in nine neonates without warming their feet, capillary concentrations of noradrenaline were higher than arterial values (p less than 0.03) and those of adrenaline were not different from arterial values. Catecholamine concentrations in arterialized capillary plasma collected in healthy full-term infants at 1 h [n = 9; noradrenaline: 6.85 (3.09-8.88) nmol/L; adrenaline: 1.34 (0.86-2.85) nmol/L] and 5 d after birth [n = 27; noradrenaline: 1.58 (0.89-3.16) nmol/L; adrenaline: 0.59 (0.25-1.64) nmol/L] reflect the well-known fall (p less than 0.01) in catecholamine levels after delivery. With a highly sensitive analytical technique, catecholamine concentrations can reliably be assessed in minute samples (100-200 microL) of arterialized capillary blood, even when concentrations have dropped to low "resting" basal levels. Moreover, the capillary sampling procedure is simple and safe, can easily be applied to healthy infants, and does not have the practical and ethical limitations of arterial blood sampling.

Adrenal Glands↗

The cardio-facio-cutaneous syndrome: report of a patient and review of the literature.

We report a 3-year-old girl with the cardio-facio-cutaneous (CFC) syndrome. She presented the typical combination of mild developmental delay, postnatal onset short stature with relative macrocephaly, a wide and prominent forehead with posteriorly rotated ears and down-slanting palpebral fissures, an atrial septal defect, and ectodermal abnormalities. All cases reported to date occurred sporadically. The aetiology remains unknown; de novo mutations of an autosomal dominant gene seem the most likely explanation.

Abnormalities, Multiple↗

Incidence of congenital heart disease in Tyrol, Austria 1979-1983.

The congenital heart disease incidence study was designed to collect valid data with respect to new diagnostic methods and to an improved system of preventive health care in order to compare the results with former studies. In the years 1979-1983 there were 41,725 live births in the Tyrol. Among these, 341 cases of congenital heart disease were recognised giving an incidence of 8.2 per 1000. This does not imply a real increase in congenital heart disease, but can be explained by differences in methodological bias. As in previous investigations as well in our study, ventricular septal defect has been noted as the most common cardiac lesion. A remarkable result is a 56% incidence of spontaneous closures. Within five years, 81 children died; 89% of them died by the age of one year.

Austria↗

[Aberrant course of the left pulmonary artery--a contribution to a rare disease picture].

An anomalous left pulmonary artery obstructs the right main bronchus and/or the trachea. Depending on the severity of the obstruction, symptoms range from a more or less disturbing stridor over attacks of shortness of breath to a life-threatening or even lethal apnoea. An 18-month-old girl suffering from a mild form of this anomaly is presented. The diagnostic and therapeutic possibilities are discussed. After exact clarification of the characteristics of the pulmonary sling, exclusion of associated aberrations, and considering good experience with a former case a conservative approach is recommended if the patient is not substantially impaired.

Bronchial Diseases↗

[Lactic acid acidosis with mitochondrial myopathy due to a pyruvate dehydrogenase deficiency].

We report on a patient, now 17 year old, in whom lactic acidosis was detected at the age of 7 while attempting to diagnose the causes of increasing weakness. The laboratory examinations revealed elevated pyruvate, alanine and oxaloacetate levels in serum and also a lowered citrate level. This led us to suspect a disturbance of the pyruvate dehydrogenase complex. Reduced pyruvate dehydrogenase activation in leucocytes and muscle tissue was indeed found. This article reports on the 10 year history of this case and attempts to establish a connection between the various symptoms observed and the underlying metabolic defect.

Acidosis↗

[Diagnosis of congenital pleuropericardial defects].

Pleuro-pericardial defects have been found incidentally during post mortems or chest surgery but, because of their usual lack of symptoms, are rarely found otherwise. If suspicion of such a malformation arises, it should be clarified because of possible herniation of the atrium or ventricle. The necessary diagnostic steps are discussed in relation to two patients and the value of chest x-rays is stressed. A pleuro-pericardial defect should be diagnosed because of the typical radiological changes of the cardiac contour. Only in exceptional cases should it be necessary to induce a diagnostic pneumothorax or to perform an exploratory thoracotomy.

Child, Preschool↗

[The use of midodrin in the treatment of the orthostatic syndrome (author's transl)].

Midodrin, a new alpha-mimetic drug, has been studied with respect to its therapeutic effectiveness in children suffering from orthostatic hypotension. The study was carried out as a double blind trial against placebo. A statistically significant improvement was found only in relation to the following symptoms: "tendency to collapse", "dizziness", "headache", "change of colour". Blood pressure- and ECG alterations within the framework of the Schellong orthostatic and functional test were not significantly different statistically. This might be due to the small number of patients examined, to a placebo-effect or perhaps due to the inconsistent findings inherent in this last test.

Child↗

[Agenesis of the ductus arteriosus Botalli and premature closure of the foramen ovale, in combination with mitral valve atresia, hypoplastic left ventricle, transposition of the great arteries, and pulmonary valve atresia (author's transl)].

Agenesis of the Ductus arteriosus Botalli is a rare anomaly, which is known to occur in combination with truncus arteriosus, tetralogy of Fallot with pulmonary valve agenesis and also in simple tetralogy. The authors report on a case, where neither a ductus nor any remnant of it could be found in a complex heart malformation consisting of premature closure of the Foramen ovale, mitral atresia, hypoplastic left ventricle, transposition of the great arteries, pulmonary valve atresia and hypoplastic pulmonary artery. Speculations as to the pathogenesis of this anomaly presume slowing and eventual arrest of the ductal blood flow as a consequence of closure of the Foramen ovale in early fetal life. Thus total involution and disappearance of the distal part of the sixth aortic arch also on the left side seem conceivable.

Autopsy↗