Effects of Feedback on Chest Compression Quality: A Randomized Simulation Study

OBJECTIVES

Our aim for this study was to test whether visual and verbal feedback compared with instructor-led feedback improve the quality of pediatric cardiopulmonary resuscitation (CPR).

METHODS

There were 653 third-year medical students randomly assigned to practice pediatric CPR on 1 of 2 manikins (infant and adolescent; n = 344 and n = 309, respectively). They were further randomly assigned to 1 of 3 feedback groups: The instructor feedback (IF) group (n = 225) received traditional, instructor-led feedback without any additional feedback device. The device feedback (DF) group (n = 223) received real-time visual feedback from a feedback device. The instructor and device feedback (IDF) group (n = 205) received verbal feedback from an instructor who continuously reviewed the trainees' performance using the feedback device. After the training, participants' CPR performance was assessed on the same manikin while no feedback was being provided.

RESULTS

For the primary outcome of total compression score, participants in the DF and IDF groups performed similarly, with both groups showing scores significantly (P < .001) better than those of the IF group. The same findings held for correct hand position and the proportion of complete release. For compression rate, the DF group was at the higher end of the guideline for 100 to 120 chest compressions per minute compared with the IF and IDF groups (both P < .001). No effect of feedback on compression depth was found.

CONCLUSIONS

Chest compression performance significantly improved with both visual and verbal feedback compared with instructor-led feedback. Feedback devices should be implemented during pediatric resuscitation training to improve resuscitation performance.

Discrepancy between invasive and non-invasive blood pressure readings in extremely preterm infants in the first four weeks of life

Background

The agreement between invasive and non-invasive blood pressure (BP) readings in the first days of life of preterm infants is contentiously debated.

Objective

To compare mean, systolic and diastolic invasive (IBP) and non-invasive BP (NBP) readings obtained during routine care in the first four weeks of life of extremely preterm infants.

Methods

We extracted pairs of IBP and NBP readings obtained from preterm infants born below 28 weeks of gestation from the local database. After exclusion of erroneous measurements, we investigated the repeated measures correlation and analyzed the agreement (bias) and precision adjusted for multiple measurements per individual.

Results

Among 335 pairs of IBP and NBP readings obtained from 128 patients, we found correlation coefficients >0.65 for mean, systolic and diastolic BP values. The bias for mean BP readings was -0.4 mmHg (SD 6.1), for systolic BP readings 6.2 mmHg (SD 8.1), and for diastolic BP readings -4.3 mmHg (SD 6.5). Overestimation of systolic IBP and underestimation of diastolic IBP by the non-invasive measurement were found both in the group with gestational age from 23 to 25.9 weeks and in the group with gestational age from 26 to 27.9 weeks. Systolic NBP readings tended to exceed invasive readings in the range <50 mmHg (bias 9.9 mmHg) whereas diastolic NBP readings were lower than invasive values particularly in the range >30 mmHg (bias -5.5 mmHg).

Conclusion

The disagreement between invasive and non-invasive BP readings in infants extends to the first four weeks of life. Biases differ for mean, systolic and diastolic BP values. Our observation implies that they may depend on the range of the blood pressure. Awareness of these biases and preemptive concomitant use of IBP and NPB readings may contribute to reducing over- or under-treatment.

Lymphoma in Danon disease with chronic rhabdomyolysis treated with EPOCH-R: A case report

Rare disorders often represent a challenge for clinicians and require close collaboration of an interdisciplinary team.We present the complex case of a 22-year-old male with Danon disease and late-onset of posttransplant lymphoproliferative disorder after heart transplantation. The critical aspects of his condition were: pre-existing rhabdomyolysis; infiltration of muscle and gut with lymphoma; advanced clinical stage with bulky disease; nonresponsiveness to the reduction of immunosuppression and rituximab monotherapy; expected cardiotoxicity of anthracyclines. Therefore, the patient was treated with the EPOCH-R protocol, which includes continuous administration of doxorubicin over 4 days, instead of R-CHOP, in which the anthracycline is given in a short single infusion. Complete remission was achieved after the third cycle; rhabdomyolysis did not increase and heart function was not affected. The patient received a total of 6 cycles and is still in metabolic complete remission.We conclude that patients with Danon disease can be treated with anthracycline-containing chemotherapy and that continuous infusion of EPOCH-R does not exacerbate pre-existing rhabdomyolysis.

Fetal MRI detects early alterations of brain development in Tetralogy of Fallot

OBJECTIVE

Prenatal imaging has identified alterations of brain growth in fetuses with congenital heart disease. However, little is known about the timing of altered brain development and its occurrence in specific congenital heart disease subgroups. This magnetic resonance imaging study aimed to identify early (median, 25 gestational weeks [GW]) changes in fetal total brain (TBV), gray matter (GMV), and subcortical brain (SBV) volumes in Tetralogy of Fallot (TOF) cases in utero.

STUDY DESIGN

Fetal magnetic resonance imaging (1.5 Tesla) was performed in 24 fetuses who were diagnosed with TOF and 24 normal age-matched control fetuses (20-34 GW). TBV, GMV, SBV, intracranial cavity, cerebellar, ventricular, and external cerebrospinal fluid volumes were quantified by manual segmentation based on coronal T2-weighted sequences. Mixed model analyses of variance and t-tests were conducted to compare cases and control fetuses.

RESULTS

TBV was significantly lower (P < .001) in early (<25 GW) and late TOF cases. Both GMV (P = .003) and SBV (P = .001) were affected. The GMV-to-SBV ratio declined in fetuses with TOF (P = .026). Compared with normal fetuses, ventricular volume was increased (P = .0048). External cerebrospinal fluid was enlarged in relation to head size (P < .001). Intracranial cavity volume (P = .314) and cerebellar volume (P = .074) were not significantly reduced in fetuses with TOF.

CONCLUSION

TOF is associated with smaller volumes of gray and white matter and enlarged cerebrospinal fluid spaces. These changes are present at ≤25 GW and indicate altered fetal brain growth in this pathophysiologic entity during early stages of human brain development.

The Effects of Hemodynamic Alterations on Lung Volumes in Fetuses with Tetralogy of Fallot: An MRI Study

This study assessed whether the presence of tetralogy of Fallot (TOF) affects fetal lung development and whether these fetuses are at risk of pulmonary hypoplasia (PH). Furthermore, we investigated whether the degree of the concomitant pulmonary valve (PV) stenosis or a stenosis in the branch pulmonary arteries correlates with the fetal lung volume. Lung volumetry was performed in 16 fetuses with TOF who underwent MRI between gestational weeks 21 and 35 and in 22 controls. Fetal biometric data and the diameters of the PVs were evaluated by ultrasound. PV and branch pulmonary artery diameters were standardized (z-scores), and fetal lung volume/fetal body weight (FLV/FBW) ratios (ml/g) were calculated. The mean FLV/FBW ratio (0.031 ± 0.009 ml/g) in the TOF group was statistically significantly lower than in the control group (0.041 ± 0.009 ml/g; P = 0.003). None of the fetuses with TOF met the criterion for PH. FLV did not correlate with the degree of PV stenosis, but rather with the presence of a significant stenosis in at least one branch pulmonary artery. The presence of TOF moderately affects fetal lung growth, which is apparently not dependent on the degree of the PV stenosis. However, only an additional stenosis in at least one branch pulmonary artery was associated with a small FLV, but not with PH. Thus, reduced pulmonary blood flow may be offset by additional factors, such as the ability to establish a sufficient collateral system and to alter structural vascular size and, thus, pulmonary vascular resistance.

Preterm infants who later require duct ligation show different vital signs and pH in early postnatal life

AIM

The study investigated early postnatal vital signs in very low birthweight (VLBW) infants who later developed patent ductus arteriosus (PDA). We hypothesised that the early postnatal course of vital signs and blood gas variables might differ between infants whose PDA closed spontaneously, those who responded to ibuprofen and those who later required PDA ligation.

METHODS

We analysed computerised records of VLBW infants born <28 weeks of gestational age, including vital signs, arterial pH values and echocardiographic data from the first postnatal days.

RESULTS

In total, 104 infants were included in the study. In the group of infants born <26 weeks of gestational age and requiring ibuprofen for PDA (n = 34), 12 infants ultimately required surgical ligation. Infants requiring ligation showed significantly lower oxygen saturation (p = 0.019), mean blood pressure (p = 0.034) and higher heart rate fluctuation ranges (p = 0.040) in the first five postnatal days than those who responded to ibuprofen. In multivariable logistic regression analysis, lower pH values in the first 48 h predicted the subsequent requirement for ligation independent of gestational age (p = 0.004).

CONCLUSION

Patients <26 weeks of gestational age requiring PDA ligation showed significant differences in the course of vital signs and pH during the first days of life.

Ventriculo-arterial coupling in children with Still's murmur

Still's murmur is the most common innocent heart murmur in children and considered flow related; however, so far the cause of the murmur has not yet been fully explained. Assessment of the hemodynamic ventriculo‐arterial interaction and the proportional anatomical dimensions of the left ventricle and the aortic root were the objective for this study. This case–control study was conducted at the Division of Pediatric Cardiology, Vienna Medical University, including healthy children with and without Still's murmur. To assess ventriculo‐arterial interaction, the model of ventriculo‐arterial coupling (VAC) was applied. The model describes the interaction between the left ventricle (left ventricular contractility, E_LV) and the arterial system (effective arterial elastance, E_A) by the VAC ratio E_A/E_LV. The parameters E_A and E_LV can be derived from M‐mode echocardiography thereby allowing a noninvasive pressure–volume analysis. Outcomes comprised VAC ratio and diameters of both the aortic root (AOD) and the left ventricle in end diastole (LVED) and end systole (LVES) as well as their relative proportions, ejection fraction (EF), stroke volume (SV), blood pressure (BP), and heart rate (HR). Forty‐three healthy children with Still's murmur (mean age 5.2 years) and 42 healthy children without murmur (mean age 5.8 years) participated in this study. Children with Still's murmur had a significantly lower VAC ratio E_A/E_LV (0.5 ± 0.13 vs. 0.59 ± 0.15; P < 0.005), a significantly higher EF% (67.1 ± 5.8 vs. 63.3 ± 5.6; P < 0.005, P < 0.01), and a larger SV per kg bodyweight (1.84 ± 0.33 vs. 1.68 ± 0.38; P < 0.05) than controls. BP, HR, and diameters of AOD, LVED, and LVES as well as their relative anatomic proportions did not differ between children with Still's murmur and controls. Still's murmur seems to be generated by a subtle alteration in ventriculo‐arterial coupling in healthy children. This result can be translated to parents, as they may be informed that their child's innocent murmur is caused by a more “lively interplay between the heart and the aorta.”

So far, the physiology of Still's murmur has not yet been defined. This study is the first to describe a significant difference in ventriculo‐arterial coupling in healthy children with and without Still's murmur.

Incidence of thrombotic and bleeding complications during cardiac catheterization in children: comparison of high-dose vs. low-dose heparin protocols

BACKGROUND

During cardiac catheterization (CC) in children, unfractionated heparin (UFH) is used for primary prophylaxis of thrombotic events (TE). However, the optimal UFH dose to minimize TE and bleeding in children has yet to be established.

OBJECTIVES

To (i) objectively assess the incidence of TE and bleeding during pediatric CC using clinical assessment and ultrasound; and (ii) compare a high-dose vs. low-dose UFH protocol for thromboprophylaxis.

METHODS

A randomized controlled trial (RCT) comparing high-dose UFH (100 units kg(-1) bolus, followed by 20 units kg h(-1) continuous infusion) vs. low-dose UFH (50 units kg(-1) bolus) during CC. Outcome assessment was by clinical examination and vascular ultrasound, performed by blinded examiners before and within 48 h after CC. Children with no consent for randomization were followed in a cohort receiving standard-of-care UFH (parallel-cohort RCT).

RESULTS

A total of 227 children were included; 137 were randomized and 90 followed in the cohort study. The overall incidence of TE was 4.6% and bleeding 6.6%. The RCT was stopped early for futility as there were no differences between the high-dose and the low-dose UFH in TE (5% vs. 3%; risk ratios [RR] 1.5, 95% confidence interval [CI] 0.3; 9) and bleeding (7% vs. 12%, RR 0.6, 95% CI 0.2; 2). There were also no differences when RCT and cohort study populations were combined.

CONCLUSIONS

The incidences of TE and bleeding during CC in children were low. There were no differences between the high-dose and the low-dose UFH protocols studied. Although Heparin Anticoagulation Randomized Trial in Cardiac Catheterization (HEARTCAT) was not designed as non-inferiority trial, low-dose UFH (50 units kg(-1) bolus) appears sufficient for thromboprophylaxis during CC.

Tachycardia-induced cardiomyopathy after functional closure of the foramen ovale in a fetus

Although fetal tachyarrhythmias are relatively rare, they are an important causes of fetal morbidity and mortality. We report a 30-week pregnant woman with fetal tachycardia, fetal hydrops and ascites. Fetal heart rate was 230 bpm. Fetal heart rate was 230 bpm. M-mode echocardiography revealed a tachycardia with a 1:1 relationship between atrial and ventricular conduction and a short time interval between ventricular and atrial contraction. These findings suggested a diagnosis of atrioventricular re-entrant tachycardia. On the third day digoxin treatment, the fetal heart rate was still 225 bpm with a 1:1 relationship between atrial and ventricular conduction. At this time, no flow across the foramen ovale was detected. Functional closure of the foramen ovale was suspected.

Danon disease: case report and detection of new mutation

Danon disease is an X-linked disorder resulting from mutations in the lysosome-associated membrane protein-2 (LAMP2) gene. We report a male patient with skeletal myopathy, mental retardation, and massive hypertrophic obstructive cardiomyopathy necessitating heart transplantation. Immunohistochemistry of skeletal muscle and leukocytes, western blot analysis of leukocytes and cardiac muscle, flow cytometry, and DNA sequencing were performed. Muscle biopsy revealed autophagic vacuolar myopathy and lack of immunohistochemically detectable LAMP-2. Diagnosis of Danon disease was confirmed by western blot analysis of myocardial tissue and peripheral blood sample of the patient showing deficiency of LAMP-2 in myocardium and leukocytes. Moreover, absence of LAMP-2 in lymphocytes, monocytes and granulocytes was shown by flow cytometric analysis. Genetic analysis of the LAMP2 gene revealed a novel 1-bp deletion at position 179 (c.179delC) at the 3' end of exon 2, resulting in a frameshift with a premature stop codon.

Special schooling in children with congenital heart disease: a risk factor for being disadvantaged in the world of employment

The objective of this study was to evaluate type of schooling in children with congenital heart disease (CHD) who were inpatients at a tertiary pediatric cardiology center. This retrospective cohort study included 227 consecutive children with CHD (male, 125; female, 102) who had been inpatients from 1996 to 2005. Data on type of schooling had been documented by the in-hospital teacher at the time of admission. Medical data were obtained by reviewing medical charts. The primary endpoint was the percentage of children requiring special schooling, which was related to the respective percentage in the Austrian pediatric background population. Furthermore, the influence of clinical and demographic covariables was assessed. Fifteen percent (vs. 3.6% in the background population) of the study cohort required special schooling; 86% of them had a history of cardiac surgery. Cardiopulmonary bypass surgery in the first year of life showed a trend for an association with an increased frequency of special schooling. There were no significant associations with the Aristotle Basic Score (a measure for procedure complexity in CHD), gender, or first language. In conclusion, the need for special schooling is increased in children with CHD.

Incidence and diagnosis of thrombosis in children with short-term central venous lines of the upper venous system

OBJECTIVES

Deep venous thrombosis in children is frequently related to central venous lines. Study objectives were to determine objectively the incidence of deep venous thrombosis in children with short-term central venous lines and to assess the diagnostic value of venography, venous ultrasonography, and echocardiography, in a prospective cohort study.

METHODS

Consecutive children with congenital heart disease requiring short-term central venous lines in the upper venous system were screened systematically for deep venous thrombosis by using venography, venous ultrasonography, and echocardiography, according to standardized protocols.

RESULTS

The study population consisted of 90 children (median age: 2.7 years; range: birth to 18 years). Most central venous lines (97%) were located in the jugular veins. The overall incidence of deep venous thrombosis was 25 cases (28%) among 90 children. Venography identified deep venous thrombosis located in the subclavian and central veins but missed most deep venous thrombosis in the jugular veins. Venous ultrasonography had good sensitivity in the jugular veins but did not detect deep venous thrombosis in central veins. Echocardiography detected only 1 case of central deep venous thrombosis.

CONCLUSIONS

The incidence of central venous line-related deep venous thrombosis in children with short-term central venous lines is high and comparable to reports for children with long-term central venous lines. Sensitivities of venography, venous ultrasonography, and echocardiography in children vary depending on the affected venous segment. A combination of diagnostic tests is required for sensitive detection of central venous line-related deep venous thrombosis in the upper venous system.

Recent trends in heart transplantation: the University of Vienna experience

Since the beginning of the University of Vienna Cardiac Transplant Program in 1984, 1086 heart transplant procedures have been performed through the end of 2007. One- and five-year survival has increased steadily over time (82% and 76%). Ten-year survival is 65%. Over the past 10 years our program has seen dramatic changes in patient selection, accepting now patients with more risk factors (Age, diabetes, elevated pulmonary resistance,..). Developments in immunosuppression have decreased incidence of infection, rejection and graft arteriosclerosis continuously. Our program continues to pursue novel strategies to improve the survival and quality of life of our heart transplant patients.

Predictors of spontaneous closure of isolated secundum atrial septal defect in children: a longitudinal study

OBJECTIVES

The goals were to assess the frequency of spontaneous closure of isolated secundum atrial septal defect in children and to identify predictors of spontaneous atrial septal defect closure.

METHODS

A retrospective cohort study was performed in a tertiary care pediatric cardiology center. Consecutive patients (n = 200) diagnosed as having isolated atrial septal defects (no multiple or fenestrated atrial septal defects, no additional congenital heart disease, and no syndromes) were monitored for > 6 months with serial 2-dimensional echocardiography, according to a standardized protocol.

RESULTS

The median age at diagnosis was 5 months (minimum: 0 months; maximum: 13.9 years). The atrial septal defect diameter at diagnosis was 4 to 5 mm in 40% of cases, 6 to 7 mm in 28% of cases, 8 to 10 mm in 21% of cases, and > 10 mm in 11% of cases. The median age at the final follow-up evaluation was 4.5 years (range: 6.8 months to 16.2 years). Thirty-four percent of atrial septal defects showed spontaneous closure, and 28% decreased to a diameter of < or = 3 mm. Logistic regression analysis revealed atrial septal defect diameter and age at diagnosis as independent predictors of spontaneous closure or regression to < or = 3-mm defect size. Of atrial septal defects with a diameter of 4 to 5 mm at diagnosis, 56% showed spontaneous closure, 30% regressed to a diameter of < or = 3 mm, and none required surgical closure. Of atrial septal defects with a diameter of > 10 mm at diagnosis, none closed spontaneously, whereas 77% required surgical or device closure. Gender and observation time were not associated with spontaneous atrial septal defect closure or regression to < or = 3 mm.

CONCLUSIONS

In the present study population of children with atrial septal defects, 62% showed spontaneous closure (34%) or regression to < or = 3 mm (28%). Initial atrial septal defect diameter was the main predictor of spontaneous closure.

PHACES: a neurocutaneous syndrome with anomalies of the aorta and supraaortic vessels

The acronym PHACES summarizes the most important manifestations of a rare neurocutaneous syndrome. Specifically, "P" accounts for malformation of the brain in the region of the posterior fossa, "H" stands for haemangiomas, "A" is for arterial anomalies, and "C" is for coarctation of the aorta along with cardiac defects, "E" is for abnormalities of the eye, and "S" for clefting of the sternum, and/or a supraumbilical abdominal raphe. Our objective is to introduce the syndrome to paediatric cardiologists. Our patient has stenosis of the aortic arch, multiple malformations of the great vessels arising from the aortic arch, intracranial vascular abnormalities, a sternal malformation with a supraumbilical raphe, and facial haemangiomas. We stress that it is important always to consider the existence of this syndrome in all patients with facial haemangiomas.

Early failure of the tissue engineered porcine heart valve SYNERGRAFT in pediatric patients

OBJECTIVES

The first tissue engineered decellularized porcine heart valve, Synergraft (Cryolife Inc., USA) was introduced in Europe as an alternative to conventional biological valves. This is the first report of the rapid failure of these new grafts in a small series.

MATERIALS AND METHODS

In 2001, 2 model 500 and 2 model 700 Synergraft valves were implanted in four male children (age 2.5-11 years) in the right ventricular outflow tract as a root. Two patients had a Ross operation and two had a homograft replacement.

RESULTS

The cryopreserved Synergraft valves appeared macroscopically unremarkable at implantation. Recovery from surgery was uneventful and good valve function was demonstrated postoperatively. Three children died, two suddenly with severely degenerated Synergraft valves 6 weeks and 1 year after implantation. The third child died on the 7th day due to Synergraft rupture. Subsequently the fourth graft was explanted prophylactically 2 days after implantation. Macroscopically all four grafts showed severe inflammation starting on the outside (day 2 explant) leading to structural failure (day 7 explant) and severe degeneration of the leaflets and wall (6 weeks and 1 year explant). Histology demonstrated severe foreign body type reaction dominated by neutrophil granulocytes and macrophages in the early explants and a lymphocytic reaction at 1 year. In addition significant calcific deposits were demonstrated at all stages. Surprisingly pre-implant samples of the Synergraft revealed incomplete decellularization and calcific deposits. No cell repopulation of the porcine matrix occurred.

CONCLUSION

The xenogenic collagen matrix of the Synergraft valve elicits a strong inflammatory response in humans which is non-specific early on and is followed by a lymphocyte response. Structural failure or rapid degeneration of the graft occurred within 1 year. Calcific deposits before implantation and incomplete decellularization may indicate manufacturing problems. The porcine Synergraft treated heart valves should not be implanted at this stage and has been stopped.

Infantile sialic acid storage disease and protein-losing gastroenteropathy

We report on a boy who presented at birth with gastroschisis and thereafter developed the characteristic clinical symptoms of infantile sialic acid storage disease within the first two months of life. Measurements of free sialic acid excretion (tenfold increase) in the urine and a 15-fold elevation of free sialic acid in cultured fibroblasts proved the diagnosis. The clinical course was complicated by hypertrophic cardiomyopathy, recurrent infections, hypothyroidism, and intestinal protein losses, which had never been described before in an infantile sialic acid storage disease patient. The child died at the age of 10 months. Clinical and laboratory findings are discussed and compared with other cases described in the literature.

Self-concept in male and female adolescents with congenital heart disease

Cognitive achievement, behavioural problems, and various dimensions of personality were assessed in 48 male and female patients with congenital heart disease (CHD) aged from 12 to 16 years in comparison to a control group. The CHD group showed a lower speed of cognitive processing but seemed to have less state-anxiety and to possess a higher superego strength. Male adolescents with CHD presented with a reduced perceived capacity and self-esteem. This was not true for adolescent girls with CHD. The negative self-concept of boys with CHD may be partly explained by reduced physical ability interfering with peer relationships.

Interventional stent implantation in a child with patent ductus venosus and pulmonary hypertension

We report on the rare case of a 4-year-old boy with patent ductus venosus and pulmonary hypertension presenting with progressive fatigue, tachypnoea at rest and tachycardia. Cardiac catheterisation revealed suprasystemic pressure in the pulmonary arteries with severely elevated pulmonary vascular resistance. In order to reduce the diameter of the ductus venosus, a stent was implanted interventionally, which closed, as expected, spontaneously 2 years later. Pulmonary arterial pressure and pulmonary vascular resistance decreased significantly and the general condition of the boy improved dramatically.

CONCLUSION

To the best of our knowledge, this represents the first report of successful interventional stent occlusion of a patent ductus venosus associated with severe pulmonary hypertension. The future will tell whether this intervention is curative or represents a bridging procedure for subsequent liver transplantation.

Survival after intrauterine myocardial infarction: noninvasive assessment of myocardial perfusion with 99mTc-Sestamibi scintigraphy

Survival after severe intrauterine myocardial infarction has not been reported previously. We describe the course of a neonate with a structurally normal heart, who presented with cardiogenic shock at birth due to intrauterine myocardial infarction with a huge ventricular aneurysm. Myocardial perfusion was assessed noninvasively by means of 99mTc-Sestamibi, a radiopharmaceutical agent recently introduced in nuclear cardiology to avoid repeated coronary angiography. The patient survived with improved cardiac function and normal neurodevelopmental outcome.

Is there a possible role for haemostasis in the development of perigraft reaction complicating the modified Blalock Taussig shunt?

The perigraft reaction is an unusual complication found in patients in whom a modified Blalock Taussig shunt has been created using a polytetrafluoroethylene graft. We found that, in two infants, consistent laboratory findings during such a perigraft reaction were hypofibrinogenemia, increased levels of thrombin-antithrombin III complex, prothrombin fragment 1 and 2 and products of degradation of fibrin. Normalization of the levels of fibrinogen produced resolution of the perigraft reaction.

Extracorporeal life support in pediatric patients with heart failure

The prognosis of patients with end-stage heart failure presenting with acute clinical deterioration is poor. Extracorporeal membrane oxygenation (ECMO), however, can provide univentricular and biventricular cardiac support which has led to the extended application of ECMO to infants and children. With improving results, indications and modalities of mechanical support have changed, and mechanical bridge to cardiac transplantation will offer extended survival for selected patients. The purpose of this article is to provide comprehensive data of pediatric cardiac support and to discuss the central role of echocardiography in the estimation of cardiac performance during mechanical support. As a conclusion, one can predict that the encouraging results of today will lead to further technological developments, which will create individual technical solutions of different clinical applications.

Scintigraphic assessment of pulmonary and whole-body blood flow patterns after surgical intervention in congenital heart disease

Glenn shunt and Fontan procedure, the most widely used surgical procedures in congenital heart anomalies, may be associated with abnormal pulmonary blood flow patterns and the development of pulmonary arteriovenous fistulae.

METHODS

This study quantified pulmonary and whole-body blood flow using the microsphere technique by sequential injection of 99mTc microspheres into upper and lower limb veins and performing planar lung imaging in four projections and anterior and posterior whole-body scans in 46 patients with either Glenn shunt or Fontan procedure. The right-to-left shunt volume was estimated by a brain and kidneys-to-lungs ratio and compared with calculations from the whole-body scans.

RESULTS

In 31 of 46 patients, the blood from the superior vena cava was drained preferentially into the right lung (75%+/-19%). The inferior venous system was drained equally into both lungs. The right-to-left shunt volume was 24%+/-12% after injection into the superior caval system, 50%+/-18% after injection into the inferior caval system. A subgroup of patients who had undergone a palliative Blalock-Taussig shunt (BTS) before the final surgery showed a perfusion pattern that was not known after pulmonary angiography or contrast echocardiography: 15 of 24 patients with BTS had hypoperfusion of the upper lobe on the side of the BTS after injection into the arm vein and corresponding normal perfusion or hyperperfusion when injected into the foot vein.

CONCLUSION

Lung perfusion scintigraphy after tracer application into the superior and inferior caval systems detects more abnormal pulmonary blood flow patterns than contrast echocardiography and is the only procedure able to quantify right-to-left shunt volume individually for the superior and inferior caval systems. Thus, this diagnostic technique should be part of the routine follow-up in children after Glenn shunt or Fontan procedure.

Echocardiographic evidence of aortopulmonary collaterals in premature infants after closure of ductus arteriosus

Aortopulmonary collaterals occur in a variety of congenital heart diseases, in chronic pulmonary infection and abscesses, in association with lung tumors, and after multiple pulmonary emboli. In patients with congenital cyanotic heart disease aortopulmonary collaterals mainly occur in conditions with reduced pulmonary blood flow. We investigated 12 preterm low-birth-weight infants, gestational age 29.3+/-3.3 weeks, with respiratory failure who suffered from moderate to severe chronic lung disease after a period of mechanical ventilation. All patients developed aortopulmonary collaterals after closure of a patent ductus arteriosus. Aortopulmonary collaterals could be displayed clearly by color Doppler echocardiography and originated mainly from the descending aorta or the aortic arch. Hypoxic and hypercapnic episodes favored the development of aortopulmonary collaterals, which disappeared after pulmonary hemodynamics and respiratory function had improved. In only one patient coiling of a large col lateral vessel had to be performed. Systemic-to-pulmonary collateral vessels potentially aggravate chronic lung disease by increasing collateral pulmonary blood flow and reducing lung compliance. We conclude that aortopulmonary collaterals occur in bronchopulmonary dysplasia and can cause major problems in ventilated premature infants. Echocardiographic evaluation is important to prevent aggravation of chronic lung disease of infants at risk.

[Hypoplastic left-heart syndrome. Initial intensive care experiences with the Norwood operation in Vienna]

Palliative surgery of the hypoplastic left heart syndrome (HLHS), whereby both pulmonary and systemic circulation are restored, was first described by Norwood in 1983. Careful ventilatory and pharmacologic modulation of the ratio of pulmonary to systemic vascular resistance are a crucial part of pre-, peri- and postoperative management. We report our experience in 3 of 7 newborns with HLHS who underwent the Norwood operation. Hemodynamic and respiratory parameters were evaluated retrospectively in these patients and we analysed the influence of diagnostic and therapeutic interventions on the course of disease before and after operation. During prostaglandin therapy two of three patients required mechanical ventilation preoperatively because of pulmonary hyperperfusion. Decreased myocardial contractility, oliguria and increased pulmonary vascular resistance characterized the postoperative course. The management included a careful application of inotropic support when necessary, adaptation of the ventilatory setting in order to modulate pulmonary perfusion and, in addition, institution of peritoneal dialysis. One patient died from staphylococcus aureus and superinfection with respiratory syncytial virus on day 41 after the operation. Maintaining an optimal balance between pulmonary and systemic blood flow is an essential aspect of postoperative management. Serum lactate and central venous oxygen saturation are helpful parameters in monitoring therapeutic measures in these patients. We conclude from our preliminary experience, that the Norwood operation might be an alternative therapeutic approach for newborns with HLHS in whom heart transplantation is not possible.

[Bacterial endocarditis in childhood]

BACKGROUND

Bacterial endocarditis in childhood is a rare but serious disease. The group of children with congenital heart disease at risk to develop bacterial endocarditis increases, because more children survive with advanced medical and surgical management. Rheumatic Fever as predisposing heart disease decreases and is of reduced importance.

PATIENTS

From 1983 to 1993 16 patients in the age of 0.3 to 17.6 years (mean 10.6 years) were received by the Department of Pediatric Cardiology of the University Children's Hospital Vienna with the diagnosis "bacterial endocarditis". A congenital heart disease was known previously in 13 cases: 4 children had VSD, 2 children had Tetralogy of Fallot, 1 child had a single ventricle and an infundibular pulmonary stenosis, 4 children had pulmonary atresia, 1 child had a cleft of the mitral valve, and 1 child had a coronary artery fistula. Moreover, 1 child had a mitral valve prolapse with valvular regurgitation as a consequence of Marfan-Syndrome. 6 children with congenital heart disease had been treated surgically previously.

METHODS

Medical data of all patients with the diagnosis of "bacterial endocarditis" between 1983 and 1993 were analysed. It was this period when echocardiography was used for the first time to contribute to diagnosis and course control.

RESULTS

In 11 of 16 cases positive blood cultures were obtained. Mostly Streptococcus viridans (4 cases) and Staphylococcus aureus (3 cases) were isolated. During the parenteral therapy with antibiotics 9 children suffered as a side effect from a drug induced fever and/or decreasing leucocytes and thrombocytes or a rash. In addition to the antibiotic therapy 8 children were treated surgically. One child died immediatly after the operation. 15 of the 16 patients with endocarditis survived.

CONCLUSIONS

With children with known heart disease the recommendations for the prevention of bacterial endocarditis have to be strictly followed and every long ongoing feverish disease has to be carefully examinated.

Erythropoietin, erythropoesis and iron status in children after major surgical stress

The aim of our study was to evaluate bone marrow stimulation and bone marrow response to post-operative anaemia in children after open heart surgery. In 16 children (age 5.7 +/- 0.9 years, weight 20.1 +/- 3.2 kg) serum erythropoietin, haematocrit, reticulocyte count, ferritin, transferrin saturation and C-reactive protein were assessed perioperatively after cardiopulmonary bypass for surgical repair of atrial septal defect. Erythropoietin increased seven fold from 14 +/- 6.2 (7-30) to 80 +/- 49 (20-171) mU/ml (P < 0.05) and the reticulocyte count a 1.7-fold from 11.1 +/- 3.1 (6-19) to 18.4 +/- 5.9 (10-31) / 1000 (P < 0.05). Transferrin saturation was inversely correlated to C-reactive protein.

CONCLUSION

These findings suggest adequate bone marrow stimulation but an inadequate bone marrow response during the immediate perioperative period, caused by inhibition of erythropoesis by acute postoperative inflammation in children after open heart surgery.

Doppler flow profiles in the right and left pulmonary artery in children with congenital heart disease and a bidirectional cavopulmonary shunt

The systolic and diastolic Doppler tracings in the right and left pulmonary artery were analyzed in 10 patients with complex cyanotic congenital heart disease, aged 6 months to 12 years (median 3 years), after employment of a bidirectional cavopulmonary shunt. The postoperative interval ranged from 2 weeks to 1.7 years (median 1.3 years). In children with pulmonary atresia or severe pulmonary stenosis with minimal antegrade pulsatile pulmonary blood flow Doppler echocardiography confirmed a systolic and diastolic bidirectional shunt from the vena cava superior to both pulmonary arteries. In children with pulmonary stenosis, Doppler echocardiography confirmed a systolic shunt only to the right pulmonary artery and a diastolic bidirectional shunt into both pulmonary arteries. As the left pulmonary artery was perfused by the pulsatile transvalvular flow it was difficult to detect a concomitant systolic Glenn-related flow in those patients. Quantitative analysis of the diastolic Doppler tracings revealed a significant difference in the velocity time integral in the right and left pulmonary artery indicating a dominant right lung perfusion in diastole.

Intercoronary collateral flow detected by Doppler colour flow mapping is an additional diagnostic sign in children with anomalous origin of the left coronary artery from the pulmonary artery

Intercoronary collateral flow within septal collaterals was detected by colour-coded Doppler echocardiography in three children with anomalous origin of the left coronary artery from the pulmonary artery. In each of the three patients angiography confirmed the presence of septal collaterals.

Anomalous origin of the left coronary artery: a review of surgical management in 13 patients

Over the last decades, surgical management of anomalous left coronary artery originating from the pulmonary artery (ALCAPA) has seen a considerable evolution. Between 1965 and 1992, 13 children with age at operation ranging between 2 months and 11 years (mean 23 months) underwent one of 5 different surgical procedures: ligation (n = 3), direct aortic reimplantation (n = 7), subclavian (n = 1) or internal mammary (n = 1) artery anastomosis, or modified aortic implantation (Vigneswaran-procedure, n = 1). There were 3 early and one late deaths resulting in an overall mortality of 30.7%. Mortality was 66.7% in the ligation group, and 20% in the revascularization group (28.6% in the subgroup with direct aortic implantation). The one late death occurred 6 months after ligation. Follow-up ranges between 3 months and 21 years, mean 7.3 years. All but one survivors are in NYHA functional class I. Following operative correction, there was clear improvement in left ventricular performance. Our data give reason to suggest ALCAPA to be more frequent than considered so far. Early surgery is recommended in all patients with ALCAPA, regardless of age or symptomatic status. Reestablishment of a two-coronary system is considered the procedure of choice. All survivors require long-term follow-up controls of early recognition of residual or progressive cardiac problems.

Two-dimensional and Doppler echocardiographic follow-up after the arterial switch operation for transposition of the great arteries

An echocardiographic follow-up examination was performed in 20 children who underwent an arterial switch operation from November 1984 to October 1990. The age at the time of operation ranged from 1 to 54 days, the weight ranged from 2.5 to 4.5 kg body weight. The time interval from the day of operation and the examination ranged from 3 to 74 months. M-mode echocardiography showed hypokinetic left ventricular function in 6 patients (30%). Abnormal segmental left ventricular wall motions were found in 6/16 patients (37.5%). Doppler echocardiographic examination at the site of the pulmonary anastomosis revealed an instantaneous gradient less than 20 mmHg in 9 patients (45%), a gradient between 20 and 60 mmHg in 9 patients (45) and a gradient greater than 60 mmHg in two patients (10%). The location of the stenosis was just below the bifurcation in 17 patients (85%) and seemed to be related to stretching of the pulmonary trunk during the Lecompte maneuver. One patient (5%) had a supravalvular aortic stenosis with a gradient of 43 mmHg. Color-flow mapping revealed mild aortic regurgitation in 8 patients (40%) but moderate regurgitation in one patient (5%). Three patients (15%) showed mild mitral regurgitation, all of them also had hypokinetic left ventricular function.

Angiotensin converting enzyme activity in children with congenital heart disease

Serum angiotensin converting enzyme (ACE) activity was determined in 46 children with congenital heart disease with normal and abnormal lung perfusion: (1) congenital heart disease with normal pulmonary blood flow (12 patients); (2) congenital heart disease with increased pulmonary blood flow (18 patients); (3) congenital heart disease with decreased pulmonary blood flow (16 patients). There was no significant difference in serum ACE activity between the three groups. In group 2 serum ACE activity had a tendency to correlate inversely with both mean pulmonary arterial pressure (r = -0.43; P less than or equal to 0.05) and pulmonary vascular resistance (r = -0.48; P = 0.05). No further correlations between serum ACE activity and age, serum electrolytes, creatinine nor other haemodynamic data could be established.

Pharmacokinetics of intra-arterial indomethacin treatment for patent ductus arteriosus

We present pharmacokinetic data of prolonged, intra-arterial indomethacin treatment (i.e. induction plus maintenance dose) for symptomatic patent ductus arteriosus (sPDA) in 26 ventilated premature infants. sPDA was assessed by two-dimensional and pulsed Doppler echocardiography. Permanent ductal closure occurred in 20 (76%) infants. Plasma levels of indomethacin were 1.18 +/- 0.74; 1.8 +/- 1.0; 1.51 +/- 0.93 and 1.25 +/- 0.98 micrograms/ml (mean +/- SD) at 12, 24, 48 and 72 h after initial dose administration. All except one patient who responded with ductal closure, showed plasma levels above 0.25 microgram/ml throughout the 3 day treatment period and no case of sPDA reopening was noted. Although target concentrations over time were not defined, the data indicate that the maintenance levels measured were within the therapeutic range. A negative correlation was found for plasma drug levels and postnatal age (r = 0.52; P less than 0.01). Volume of drug distribution was 0.23 +/- 0.18 l/kg, total clearance 0.1 +/- 0.11 ml/min and elimination constant 0.06 +/- 0.05 h-1 (mean +/- SD). The great variation in pharmacokinetic data reflects the heterogeneity of the population studied with respect to extracellular fluid space, cardiovascular status, serum protein and other parameters.

[L-carnitine therapy and myocardial function in children treated with chronic hemodialysis]

Six out of 14 chronically hemodialysed children with significantly decreased serum carnitine levels were substituted with L-carnitine (15-30 mg/kg/day-Biocarn) up to normal and above normal carnitine levels. None of these patients were digitalised. During the time of investigation plasma carnitine levels were investigated monthly and, simultaneously, three echocardiographic parameters in M-mode were quantitatively und qualitatively determined: shortening fraction (SF-%), ratio of left ventricular pre-ejection/ejection time (LVPT/LVET) and velocity of circumferential fibre shortening (Vcf). Carnitine substitution produced measurable changes in echocardiographic parameters, and a significant quantitative improvement in left ventricular function and performance: after 6 months of carnitine substitution a 24% improvement was seen, after 18 months a 44% mean improvement. No side effects of carnitine were observed; the compatibility was good. Beside these positive effects all patients reported decreased dialysis-associated spasms and polyneuropathic symptoms and increased somatic ability.

[Value of myocardial scintigraphy of coronary anomaly in the differential diagnosis of pediatric cardiomegaly]

The differentiation between anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) and other causes of cardiomegaly and thereby the decision to operate, as opposed to undertaking conservative therapy is often extremely difficult in clinical practice. Electrocardiographically, signs of myocardial infarction can be missed in ALCAPA, other forms of dilative cardiomyopathy (DCMP) often showing similar clinical features. Up to now aortography alone can make a clear-cut distinction between these two entities. In order to determine the diagnostic value of thallium-201 myocardial scintigraphy in ALCAPA, we investigated 18 children, 7 of them with angiographically or autoptically established ALCAPA and 11 patients with DCMP. The coronary artery anomaly was diagnosed on the basis of the typical myocardial perfusion defects in only 3 of the relevant 7 patients. In 9 of the 11 patients with DCMP ALCAPA was excluded by the homogeneous perfusion pattern or small focal reduction in thallium-201 activity in the left ventricular muscle mass. In view of the overall disappointing results of this method in achieving a specific diagnosis in ALCAPA, all patients with DCMP with or without suspected fibroelastosis should undergo invasive diagnosis with aortography.

Right ventricular performance and pulmonary haemodynamics in adolescent and adult patients with cystic fibrosis

A combined haemodynamic and radionuclide approach was used to evaluate right ventricular performance in 16 adolescent and adult patients with cystic fibrosis (CF). There were nine patients with mild arterial hypoxaemia (PaO2 greater than 80% of predicted) and normal resting pulmonary artery pressure and seven patients with severe arterial hypoxaemia (PaO2 less than 70% of predicted) and resting pulmonary arterial hypertension (PH). The right ventricular ejection fraction (RVEF) by equilibrium angiocardiography using krypton 81m as a tracer and stroke volume index (SVI) by thermodilution techniques were measured simultaneously and right ventricular end-diastolic and end-systolic volumes were derived. RVEF was normal in CF patients without PH (58.9 +/- 7.2%) but was reduced in those with PH (45.4 +/- 2.6%). There was a statistically significant inverse linear correlation between RVEF and afterload as assessed by mean pulmonary artery pressure (Pap: r = -0.76) and pulmonary vascular resistance (PVR: r = -0.78), indicating that RVEF ist afterload-dependent. Right ventricular function, however, as assessed by right ventricular end-systolic pressure-volume relations was even higher in CF patients with PH, indicating preserved or even increased right ventricular function in the face of an increased afterload stress.

[Immunosuppressive treatment of chronic myocarditis]

6 children aged 9 months to 13 8/12 years developed reduced physical capacity, failure to thrive, dyspnoea on effort and heart failure after viral infection. Bed rest and anticongestive therapy did not reduce the severe heart failure. Immunosuppressive therapy with prednisolone 2 mg/kg/d and azathioprine 2 mg/kg/d was added on the assumption of chronic myocarditis (n = 4) or endocardial fibrosis (n = 2). 3 of the 6 children showed a considerable improvement in heart size, ECG and systolic heart function. Interruption of immunosuppressive therapy due to side effects in one child led to cardiac deterioration, which was reversed by renewed prednisolone therapy. Two patients died of progressive congestive heart failure. Heart transplantation was successfully performed in the now 14 year-old girl who was suffering from terminal dilated cardiomyopathy. Since there is no specific test for selecting patients who are likely to benefit from immunosuppressive therapy we feel this regimen would be justified in hopeless cases of congestive cardiomyopathy who have not responded to conventional therapy with anti-congestive drugs.

Right ventricular contractility is preserved in patients with cystic fibrosis and pulmonary artery hypertension

A combined hemodynamic and radionuclide approach was used to evaluate right ventricular contractility in 16 adolescent and adult patients with cystic fibrosis (CF). Nine patients had normal resting pulmonary artery pressure, and seven had resting pulmonary artery hypertension (PH). Right ventricular ejection fraction (RVEF) was observed by radionuclide angiocardiography, and stroke volume index (SVI) by thermodilution techniques. By combination of these measures right ventricular end-diastolic and end-systolic volumes were derived. RVEF was normal in CF patients without PH (58.9 +/- 7.2%) but was reduced in those with PH (45.4 +/- 2.3%). There was a strong inverse linear correlation between RVEF and afterload, as assessed by mean pulmonary artery pressure (r = -0.76), indicating RVEF being afterload-dependent. Right ventricular contractility, however, as assessed by right ventricular end-systolic pressure-volume relations was even higher in CF patients with PH, indicating preserved or even increased contractility in the face of an increased afterload stress. The acceleration time, evaluated by pulsed Doppler echocardiography, was normal in CF patients without PH (117.3 +/- 5.5 msec) and significantly reduced in those with PH (85.1 +/- 6.4 msec). Both RVEF and AT were efficient in estimating pulmonary artery pressure in these patients.