A multicentre survey of paediatric out-of-hospital cardiac arrest incidence, aetiology, and survival in New South Wales over an 11-year period

Funding Acknowledgements

Type of funding sources: None.

Introduction

Out-of-hospital cardiac arrest (OOHCA) is commonly associated with pulseless ventricular tachycardia and ventricular fibrillation (VT/VF) and cardiac aetiologies. One New South Wales (NSW) ambulance registry reported(1) cardiac aetiologies with a prevalence of 31% among OOHCA cases. Multicentre OOHCA data and NSW’s well-developed services for cardiac genetic predisposition screening motivate us to consider the following study of paediatric OOHCA in this state.

Purpose

We present a multicentre, retrospective study summarizing the demographics, clinical characteristics, incidence, presenting rhythm, and survival-to-discharge status of paediatric OOHCA cases in NSW over an 11-year period. We also present and categorize diagnostic outcomes for patients presenting with VT/VF.

Methods

A retrospective case series of 298 patients admitted to one of three NSW PICUs (two in Sydney and one in Newcastle) under 18 years of age and presenting with OOHCA between January 2009 and December 2019.

Results

Out of 296 paediatric OOHCA patients that survived until PICU admission, 187 (63.2%) were male and 160 (54.1%) survived until hospital discharge. Of those surviving to discharge, 105 (65.6%) were male. Presenting rhythm was asystole or pulseless electrical activity in 240 patients (84.8%, aged 0–17 years, median age 2 years), VT/VF in 41 patients (14.5%, aged 0–16 years, median age 9 years), and complete heart block in 2 patients (0.7%, aged 4–4 years, median age 4 years). Survival was higher in the VT/VF group (82.9%) relative to the asystole and pulseless electrical activity group (50.0%). Of the 41 patients presenting with VT/VF, 13 (31.7%) had a predisposing cardiac condition (2 truncus arteriosus, 1 arrhythmogenic right ventricular cardiomyopathy, 1 double outlet right ventricle, 1 hypoplastic right ventricle, 1 left ventricular non-compaction, 2 asystolic syncope, 2 left ventricular intramyocardial fibroma, 1 familial dilated cardiomyopathy, and 2 undetermined cardiac conditions) and 20 (48.8%) had a genetic condition (9 catecholaminergic polymorphic ventricular tachycardia, 4 hypertrophic cardiomyopathies, 1 Nkx-2.5 mutation, 2 Long QT syndrome, 2 PPA2 mutation, 1 TANGO2 mutation, 1 supraventricular tachycardia). Toxins or trauma were involved in 4 (9.8%) cases, while no cause was determined in 4 (9.8%) other cases.

Conclusions

Overall, 54.1% of paediatric OOHCA patients admitted to PICU survived until hospital discharge, rising to 82.9% among those with VT/VF. Genetic conditions (48.8%), predominated by CPVT, were present in over one-third of VT/VF cases: this figure confirms the continued need for detailed cardiac/genetic assessment for paediatric OOHCA cases.

Genetic markers of repolarization and arrhythmic events after acute coronary syndromes

BACKGROUND

There is a genetic contribution to the risk of ventricular arrhythmias in survivors of acute coronary syndromes (ACS). We wished to explore the role of 33 candidate single nucleotide polymorphisms (SNPs) in prolonged repolarization and sudden death in patients surviving ACS.

METHODS

A total of 2,139 patients (1680 white ethnicity) surviving an admission for ACS were enrolled in the prospective Coronary Disease Cohort Study. Extensive clinical, echocardiographic, and neurohormonal data were collected for 12 months, and clinical events were recorded for a median of 5 years. Each SNP was assessed for association with sudden cardiac death (SCD)/cardiac arrest (CA) and prolonged repolarization at 3 time-points: index admission, 1 month, and 12 months postdischarge.

RESULTS

One hundred six SCD/CA events occurred during follow-up (6.3%). Three SNPs from 3 genes (rs17779747 [KCNJ2], rs876188 [C14orf64], rs3864180 [GPC5]) were significantly associated with SCD/CA in multivariable models (after correction for multiple testing); the minor allele of rs17779747 with a decreased risk (hazard ratio [HR] 0.68 per copy of the minor allele, 95% CI 0.50-0.92, P = .012), and rs876188 and rs386418 with an increased risk (HR 1.52 [95% CI 1.10-2.09, P = .011] and HR 1.34 [95% CI 1.04-1.82, P = .023], respectively). At 12 months postdischarge, rs10494366 and rs12143842 (NOS1AP) were significant predictors of prolonged repolarization (HR 1.32 [95% CI 1.04-1.67, P = .022] and HR 1.30 [95% CI 1.01-1.66, P = .038], respectively), but not at earlier time-points.

CONCLUSION

Three SNPs were associated with SCD/CA. Repolarization time was associated with variation in the NOS1AP gene. This study demonstrates a possible role for SNPs in risk stratification for arrhythmic events after ACS.

Zebrafish as a model for long QT syndrome: the evidence and the means of manipulating zebrafish gene expression

Congenital long QT syndrome (LQT) is a group of cardiac disorders associated with the dysfunction of cardiac ion channels. It is characterized by prolongation of the QT-interval, episodes of syncope and even sudden death. Individuals may remain asymptomatic for most of their lives while others present with severe symptoms. This heterogeneity in phenotype makes diagnosis difficult with a greater emphasis on more targeted therapy. As a means of understanding the molecular mechanisms underlying LQT syndrome, evaluating the effect of modifier genes on disease severity as well as to test new therapies, the development of model systems remains an important research tool. Mice have predominantly been the animal model of choice for cardiac arrhythmia research, but there have been varying degrees of success in recapitulating the human symptoms; the mouse cardiac action potential (AP) and surface electrocardiograms exhibit major differences from those of the human heart. Against this background, the zebrafish is an emerging vertebrate disease modelling species that offers advantages in analysing LQT syndrome, not least because its cardiac AP much more closely resembles that of the human. This article highlights the use and potential of this species in LQT syndrome modelling, and as a platform for the in vivo assessment of putative disease-causing mutations in LQT genes, and of therapeutic interventions.

Echocardiographic assessment of blood flow volume in the superior vena cava and descending aorta in the newborn infant

BACKGROUND

Clinical methods of assessing adequacy of the circulation are poor predictors of volume of blood flow in the newborn preterm. Doppler echocardiography can be used to assess perfusion at various sites in the circulation.

OBJECTIVE

To assess repeatability of measurement of volume of superior vena caval (SVC) and descending aortic (DAo) flow.

DESIGN

SVC and DAo flow volume were assessed four times in the first 48 h of postnatal life in a cohort of preterm (<31 weeks) infants. Within-observer and between-observer repeatability was assessed in a subgroup of preterm infants. Normative values were derived from 14 preterm infants who required <48 h respiratory support and 13 healthy term infants.

RESULTS

Within-observer repeatability coefficient was 30 ml/kg/min for quantification of SVC flow, and 2.2 cm for DAo stroke distance. Measurement of DAo diameter had poor repeatability. Between-observer repeatability appeared poorer than within-observer repeatability. The fifth centile for volume of SVC flow in healthy preterm infants was 55 ml/kg/min and 4.5 cm for DAo stroke distance.

CONCLUSIONS

Echocardiographic assessments of volume of SVC flow and velocity of DAo flow have similar within-observer repeatability to other neonatal haemodynamic measurements. Between-observer repeatability for both measurements was poor, reflecting the difficulty of standardising these novel techniques. In this small cohort of preterm infants, SVC flow volume <55 ml/kg/min and DAo stroke distance <4.5 cm represented low or borderline systemic perfusion in the first 48 h of postnatal life.

Relationship between blood pressure and blood flow in newborn preterm infants

BACKGROUND

Arterial blood pressure remains the most frequently monitored indicator of neonatal circulatory status. However, studies of systemic perfusion in neonates have often shown only weakly positive associations with blood pressure.

OBJECTIVES

To examine the relationship between invasively monitored arterial blood pressure and four measurements of systemic perfusion: left and right ventricular outputs, superior vena caval (SVC) flow and descending aortic (DAo) flow.

DESIGN

Echocardiographic assessments of perfusion were performed four times in the first 48 h of postnatal life in a cohort of 34 preterm (<30 weeks) infants. Arterial blood pressure was monitored invasively over the exact duration of the echocardiogram.

RESULTS

In the first 48 h of postnatal life there was no evidence of a positive association between blood pressure and volume of blood flow in any of the four vessels studied. At 5 h postnatal age there was a weak but significant inverse correlation between volume of SVC flow and arterial blood pressure (p = 0.04). A similar but non-significant trend was seen at 12 h postnatal age.

CONCLUSIONS

Infants with reduced systemic perfusion tend to have normal or high blood pressure in the first hours of life, suggesting that a high systemic vascular resistance may lead to reduced blood flow. Low blood pressure does not correlate with poor perfusion in the first 48 h of postnatal life in sick preterm infants.

Neonatal tachycardias: an update

This review provides an updated framework for the diagnosis and management of neonatal tachycardias.

Near-miss SIDS due to Brugada syndrome

A 19 day old infant was successfully resuscitated from ventricular fibrillation. The 12 lead ECG was normal, with a normal QT interval, and remains so over three years follow up. DNA analysis revealed a missense mutation (R1193Q) in the SCN5A gene, previously linked with familial sudden unexpected nocturnal death syndrome, also known as Brugada syndrome.

Cardiorespiratory stability during echocardiography in preterm infants

Blood pressure, heart rate, and oxygen saturation were monitored prospectively during 40 echocardiography recordings on 17 preterm infants (25-29 weeks; 510-1430 g), to examine whether echocardiography can be performed without disturbing cardiorespiratory status in preterm infants. There was no impact on absolute blood pressure. Heart rate increased by a mean of 4 beats per minute, and oxygen saturation decreased by a mean of 1% during echocardiography. While these changes reached statistical significance they are not of clinical significance as they remained well within ranges seen during control rest periods. All readings had greater minute-to-minute variability during echocardiography but differences were small and again remained within physiological ranges.

Use of the newborn screening card to define cause of death in a 12-year-old diagnosed with epilepsy

Post-mortem investigation of sudden death in young people frequently reveals no overt cause for the death. Full investigation is hampered if tissue or blood is not retained for DNA analysis. We report a post mortem molecular diagnosis of long QT syndrome in a 12-year-old boy diagnosed with epilepsy who died suddenly playing sport. The DNA was extracted from an archived blood spot on his newborn screening ('Guthrie') card, which had been taken from him at 6 days of age. A missense mutation was detected in exon 5 of the KCNQ1 gene; R243C (835C > T), associated with long QT type 1. The same mutation was found in the mother (who now takes effective preventative therapy), but not in the sib who has now been reassured that she is not at risk of sudden death.

Transcatheter patent ductus arteriosus occlusion: evolution of techniques and results from the 1990s

OBJECTIVE

To review the evolution of transcatheter patent ductus arteriosus (PDA) occlusion techniques and results.

METHODS

A single institution, retrospective review including all patients with intention to close a PDA from 1991 to 1998, with no exclusions.

RESULTS

Rashkind occluder (n = 65), sideris double-button (n = 6), Cook detachable coil (n = 28) and Amplatzer ductal occluder (n = 4) were used. Successful implantation occurred in 99 of 103 patients. There was a need for a second transcatheter procedure to close residual ductal shunting in 12% of patients: Rashkind umbrellas (n = 8), double-button (n = 1), coils (n = 3). Eight patients (8%) required surgery, including 4 of 6 patients with the double-button occluder.

CONCLUSIONS

The Rashkind occluder and the Sideris double-button device both had an unacceptably high rate of residual shunts requiring a second transcatheter procedure or surgical closure. Detachable coils and the Amplatzer ductal occluder have become the current technology of choice for transcatheter PDA closure with high success rates.

The repeatability of echocardiographic determination of right ventricular output in the newborn

BACKGROUND

Non-invasive measurement of left ventricular output has been shown to be a repeatable technique. Little is known about the repeatability using echocardiography in determining pulmonary arterial diameters or right ventricular output.

AIMS

To find the most repeatable point at which to measure pulmonary arterial diameter, and to compare the repeatability of determining right ventricular output with left ventricular output.

METHODS

We assessed the Intra-observer and inter-observer repeatability for measuring the diameter of the pulmonary trunk in 24 term and 26 preterm infants, respectively. Interobserver repeatability was assessed for the diameters of the pulmonary trunk and aorta, for stroke distance, and for left and right ventricular output.

RESULTS

The coefficients of variation for intra-observer repeatability were 4%, 7.5% and 9% respectively for measurements of the pulmonary valve, the pulmonary trunk, and the right ventricular outflow tract. There were significant differences between observers for measurement of the pulmonary trunk (p<0.001) and right ventricular outflow tract (p=0.011) but not for the pulmonary valve measured in either its long (p=0.22) or short axis (p=0.22). Significant differences between observers were also found for the pulmonary stroke distance measured in the long axis (p=0.004) and aortic diameter at end-diastole (p<0.001). The other parameters did not differ significantly and were used to calculate right and left ventricular output, respectively. Mean left ventricular output was 241 mls/kg/min, with mean differences between observers of 0.6 mls/kg/min (95% confidence interval (CI): -39.2 to 40.3 mls/kg/min). Mean right ventricular output was 255 mls/kg/min, with mean differences of 0.3 mls/kg/min (95% CI: -24.1 to 23.4 mls/kg/min).

CONCLUSION

Measuring the diameter of the pulmonary trunk at the base of the valvar hinge points was most repeatable. Repeatability of right ventricular output was similar to that of left, with absolute values similar to those published by other workers.

NADPH diaphorase and nitric oxide synthase in the corpus cardiacum-corpus allatum of the cockroach Diploptera punctata

Juvenile hormone synthesis by corpora allata is regulated partly by allatostatin containing nerves from the brain that innervate the corpora cardiaca and the corpora allata. To investigate whether NO also participates in the regulation of juvenile hormone synthesis, antibody against NO synthase and the histochemical test for NADPH diaphorase activity, a marker for NO synthase, were applied to the corpora cardiaca-corpora allata of Diploptera punctata. Strong NADPH diaphorase activity occurred in corpus allatum cells but not in nerve fibers in the corpora allata or corpora cardiaca. In contrast, NO immunoreactivity occurred in nerves in the corpora cardiaca but not within the corpora allata. NO and allatostatin were not colocalized. NO synthase and NADPH diaphorase activity were localized in similar areas of the subesophageal ganglion and cells in the pars intercerebralis of the brain. Positive correlation of the quantity of NADPH diaphorase activity with juvenile hormone synthesis during the gonadotrophic cycle and lack of such correlation in subesophageal ganglia suggest that NADPH diaphorase activity reflects the necessity of NADPH in the pathway of juvenile hormone synthesis. These data suggest that NO is unlikely to play a significant role in the regulation of the corpora allata.

Development of a system to record cardiac output continuously in the newborn

Intermittent recordings of Doppler flow velocity and cardiac output are of value during intensive care of the sick newborn infant but result in repeated disturbance of the child. We describe a new device for making continuous precordial recordings of Doppler flow velocity from the pulmonary artery in healthy resting newborn infants. Optimal probe siting was evaluated in six babies, and signals were found to be best when the pulmonary artery was insonated from the mid left parasternum. Continuous recordings were made in 13 other babies. Pulmonary artery velocities and, by calculation, cardiac output were measured continuously over periods ranging from 24 to 60 min. Median right ventricular output ranged widely from 148 to 246 mL x kg(-1) x min(-1). In contrast, for individual babies, the values were remarkably stable: the interquartile ranges varied from 13.2 to 29.9 mL x kg(-1) x min(-1). The simultaneous display of signal power allowed independent assessment of artifactual changes in cardiac output. This technique is feasible in healthy term infants and now requires evaluation in the intensive care setting where it may provide useful information concerning trends and short-term variability in right ventricular output.

Haemodynamic effects of altering arterial oxygen saturation in preterm infants with respiratory failure

AIMS

To examine the haemodynamic effects of brief alteration in arterial oxygenation in preterm infants with respiratory failure.

METHODS

Eighteen preterm infants with respiratory failure, aged 9-76 hours, underwent detailed Doppler echocardiographic assessment at 86%, 96%, and 100% SaO2, achieved by altering the FIO2. Sixteen were receiving intermittent positive pressure ventilation, median FIO2 0.45 (0.20-0.65), median mean airway pressure 12 cm H2O (0-20). SaO2 was stable for 15 minutes at each stage. Four parameters of pulmonary arterial pressure were measured: peak velocity of tricuspid regurgitation and peak velocity of left to right ductal flow, TPV:RVET ratio and PEP:RVET ratio, measured at the pulmonary valve, along with flow velocity integrals at the aortic and pulmonary valves, and systemic arterial pressure. Ductal size was graded into closed, small, moderate, large with imaging, pulsed and continuous wave Doppler.

RESULTS

Between 86% and 96% SaO2, there were no consistent changes, but in three of the 12 with a patent ductus arteriosus (PDA) there was ductal constriction, with complete closure in one. Between 96% and 100% SaO2, peak ductal flow velocity rose significantly in four of eight with a PDA. Ductal constriction occurred in four infants; in three this was associated with a significant fall in aortic flow integral and a rise in aortic pressure (4-6 mm Hg). Overall, 11 infants went from 86% to 100% SaO2 and pulmonary arterial pressure fell significantly in seven.

CONCLUSION

A brief rise in SaO2 within the range maintained by most neonatal units can cause significant ductal constriction. The fall in pulmonary arterial pressure with 100% SaO2 seen in most infants was associated with a fall in pulmonary blood flow (or no change), rather than a rise, indicating that the dominant haemodynamic effect was ductal constriction rather than pulmonary vasodilation.

Atrial fibrillation with neonatal pulmonary lymphangiectasia

A female infant born at 28 weeks' gestation was found to have mild hydrops foetalis. Initial echocardiography showed a structurally normal heart. During the first week of life, episodic atrial tachycardia with 1:1 or 2:1 conduction was seen, requiring therapy with digoxin. The infant remained ventilator dependent, with a persistent, chylous pleural effusion which contained a preponderance of lymphocytes. Congenital pulmonary lymphangiectasia (CPL) was confirmed histologically. Worsening episodes of atrial tachycardia, including episodes of atrial fibrillation, were further investigated and a repeat echocardiogram revealed thickening of the entire right atrial wall. The cardiac findings of a thickened right atrial wall with the histological signs of myocarditis were thought to be the cause of paroxysms of atrial fibrillation, an extremely rare arrhythmia in the neonatal period. To the authors' knowledge there have been no previous reports of CPL in association with the cardiac abnormalities described herein.

Multicenter evaluation of the MicroScan Rapid Gram-Negative Identification Type 3 Panel

The accuracy and performance of the revised MicroScan Rapid Gram-Negative Identification Type 3 Panel (Dade MicroScan Inc., West Sacramento, Calif.) were examined in a multicenter evaluation. The revised panel database includes data for 119 taxa covering a total of 150 species, with data for 12 new species added. Testing was performed in three phases: the efficacy, challenge, and reproducibility testing phases. A total of 405 fresh and stock gram-negative isolates comprising 54 species were tested in the efficacy phase; 96.8% of these species were identified correctly in comparison to the identification obtained either with the API 20E system (bioMérieux Vitek, Hazelwood, Mo.) or by the conventional tube method. The number of correctly identified isolates in the challenge phase, including new species added to the database, was 221 of 247, or 89.5%, in comparison to the number correctly identified by the conventional tube method. A total of 465 isolates were examined for intra- and interlaboratory identification reproducibility and gave an agreement of 464 of 465, or 99.8%. The overall reproducibility of each individual identification test or substrate was 14,373 of 14,384, or 99.9%. The new Rapid Gram-Negative Identification Type 3 Panel gave accurate and highly reproducible results in this multiple-laboratory evaluation.

Allatostatin in hemocytes of the cockroach Diploptera punctata

Allatostatins are neuropeptides that inhibit the production, by the corpora allata, of a major insect hormone, juvenile hormone. These peptides are produced by cells of the brain and ganglia as well as by midgut endocrine cells. Transport from these sites may contribute to the allatostatin content in the hemolymph (insect blood). Using a monoclonal antibody against Diploptera punctata allatostatin I (A-P-S-G-A-Q-R-L-Y-G-F-G-L-NH2) and in situ hybridization with a digoxigenin-labeled cRNA probe generated from a portion of the allatostatin gene, it is demonstrated that allatostatin is present in and synthesized by granular hemocytes of D. punctata. About 5% of the hemocytes react with anti-allatostatin antibody and a similar number hybridize with a cRNA probe that detects allatostatin-specific mRNA. Electron micrographs showed that allatostatin-immunoreactive material occurs in membrane-bound, uniformly dense granules that frequently fill fusiform-shaped cells. Allatostatin in cell and plasma fractions of hemolymph quantified by enzyme-linked immunosorbent assay and by bioassay for inhibition of juvenile hormone synthesis in vitro indicated that about equal quantities (0.1-0.2 fmol/microl) are present in cell and plasma fractions. The production of allatostatin by hemocytes suggests that allatostatins may function as regulatory peptides in hemolymph activities in addition to their other known functions.

A regional study of presentation and outcome of hypertrophic cardiomyopathy in infants

OBJECTIVE

To describe regional incidence, presentation, and outcome of idiopathic (familial) and Noonan syndrome related infant hypertrophic cardiomyopathy (HCM) between 1969 and 1994.

DESIGN

Case series.

SETTING

Regional cardiac referral unit of the South West Region of England and south Wales, population approximately four million.

PATIENTS

21 cases of idiopathic (or familial) HCM, and eight infants with Noonan syndrome.

MAIN OUTCOME MEASURES

Survival and persistence or resolution of symptoms or cardiac hypertrophy.

RESULTS

Incidence: eight cases between 1969 and 1982 (idiopathic 6, Noonan 2), 21 cases between 1982 to 1994 (idiopathic 15, Noonan 6). Mode of presentation: cardiac failure, 17 (59%); murmur, 9 (30%); cyanosis, 2 (7%); family history, 1 (7%). Age at presentation: 0-7 days, 16 (55%); 8 days-4 months, 9 (31%); 5-12 months, 4 (14%).

OUTCOME

five deaths (17%), all < 1 year, all from progressive cardiac failure (idiopathic 3, Noonan 2). Four of these five had not received beta blockade. Among the 24 survivors (follow up 1.3-23.2 years, median 5.5 years) hypertrophy had resolved in nine (38%) (idiopathic 8, Noonan 1), was mild and asymptomatic in seven (29%), and was symptomatic or severe in eight (33%). All 10 infants presenting with septal thickness > 1.3 cm have persistent cardiac hypertrophy.

CONCLUSIONS

Mortality in infant HCM is much lower than previously reported and resolution is more frequent. This may reflect increased detection of less severe forms in addition to the success of aggressive medical management including beta blockade.

Estimation of pulmonary arterial pressure in the newborn: study of the repeatability of four Doppler echocardiographic techniques

Despite the increasing use of Doppler echocardiographic (DE) techniques to determine pulmonary arterial pressure in the neonate undergoing intensive care, there have been no studies comparing their repeatability in this population. Our objective was to compare the repeatability of four such techniques in neonates. The study was conducted in two regional neonatal units serving the North East of England. Group A (repeatability between observers): Two experienced observers performed detailed DE examinations, one directly after the other. Group B (within observer repeatability/temporal variability): One observer performed two examinations 1 hour apart. Group A comprised 15 preterm babies (26-36 weeks' gestation, 975-2915 g), most with mild respiratory failure; 4 healthy term babies; and 7 with congenital heart disease, in whom tricuspid regurgitation (TR) only was measured. Their ages were 18 hours to 12 days. Group B comprised 11 babies aged 12-64 hours with moderate to severe respiratory failure; 10 were preterm (26-36 weeks, 785-2800 g). We recorded four measurements: (1) Peak velocity of TR in m/s; (2) peak left-to-right ductal flow velocity (PDAmax in m/s); (3) TPV/RVET ratio; and (4) PEP/RVET ratio, where TPV = time to peak velocity at the pulmonary valve, PEP = right ventricular preejection period, and RVET = right ventricular ejection time. The Bland-Altman analysis was used to produce the coefficient of repeatability (CR: 95% confidence limits of repeatability), also expressed as a repeatability index (CR/mean value) and as a number of "confidence steps"-a measure of sensitivity of the technique to hemodynamic change (range of values within the population/CR). Between-observer and within-observer repeatabilities were similar. Within-observer CR and index (%) results were for TR +/- 0.26 m/s (9%); for PDAmax, +/- 0.48 m/s (39%); TPV/RVET 0.1:1.0 (34%), PEP/RVET 0.12:1.00 (36%). TR and PDAmax had the largest number of confidence steps in the expected range of values (TR 8.5; PDA max 6.5; TPV/RVET 3.2; PEP/RVET 3.2). The most repeatable technique was TR, but PDAmax would also be useful for a serial study owing to the potential for large change. Systolic time interval ratios were less repeatable and likely to be less sensitive indicators of hemodynamic change.

Haemodynamic features at presentation in persistent pulmonary hypertension of the newborn and outcome

Thirty four newborns presenting with persistent hypoxaemia in the first three days of life underwent detailed haemodynamic assessment using Doppler echocardiography, including measurements of pulmonary arterial pressure (PAP), left ventricular (LV) function, and left ventricular output (LVO). Results were compared with values from 51 healthy babies, and those of survivors were compared with non-survivors. Four of the 34 babies were excluded from this analysis because one was found to have transposed great arteries, one had a large left-to-right shunt with no evidence of persistent pulmonary hypertension, and two had diffuse skeletal myopathy. Tricuspid regurgitation was present in 70%, permitting systolic PAP estimation. The pulmonary:systemic arterial pressure ratio range was 0.7:1 to 1.83:1 (mean 1.02:1). A patent duct was present in 83%, and flow patterns indicated PAP approaching, or above, systemic pressure in all. Systolic time interval ratio TPV/RVET (time to peak velocity at the pulmonary valve/right ventricular ejection time) was mostly (65%) in the normal range, and did not correlate with other PAP measurements. LV function was below the 10th centile in only 11%, but values for LVO lay below the 10th centile in 41%, and for left ventricular stroke volume index (LSVI) in 66%. Results of 18 survivors were compared with 10 non-survivors (excluding two premature babies who died early with pulmonary interstitial emphysema). There were no significant differences for any parameter of PAP or LV function, but LVO and LSVI were significantly lower in non-survivors: LVO survivors (mean (SD)), 205 (57), non-survivors 138 (63) ml/kg/minute (P < 0.01); LSVI survivors, 1.29 (0.51), non-survivors 0.86 (0.31) ml/kg (P < 0.05). All four babies with LVO < 100 ml/kg/minute died, and 6/7 babies with LSVI < 1 ml/kg died. Detailed echocardiographic evaluation shows that the haemodynamic features of persistent pulmonary hypertension are diverse and that clinical diagnosis can be incorrect. Low LV output and stroke volume, usually with normal LV function, were the only Doppler echocardiographic parameters to predict subsequent death. This correlation with outcome requires further prospective evaluation.

Aortopulmonary collateral arteries mimicking symptomatic ductal shunting in a preterm infant

A preterm infant with bronchopulmonary dysplasia presented with clinical and Doppler echocardiographic features suggesting a left-to-right ductal shunt. The duct was ligated surgically. Clinical and echocardiographic signs did not change after ligation. Detailed colour Doppler examination ultimately showed several aortopulmonary collateral arteries giving rise to continuous turbulent flow in the main and left pulmonary arteries, similar to that seen with left-to-right ductal shunting.

Cardiovascular abnormalities in end stage renal failure: the effect of anaemia or uraemia?

Children with end stage renal failure and anaemia have an increased cardiac index and often gross ventricular hypertrophy. Correction of anaemia with recombinant human erythropoietin (r-HuEpo) for less than six months results in a reduction in the cardiac index without a significant reduction in left ventricular hypertrophy. Seven children receiving dialysis (group 1) were studied to determine whether a reduction in left ventricular hypertrophy would occur after a 12 month period of r-HuEpo. A decrease in the cardiac index was seen by six months, and a significant reduction in left ventricular mass index and cardiothoracic ratio was seen by 12 months. Successful renal transplantation also results in a reduction in the cardiac index and left ventricular hypertrophy, but the relative contributions of correction of anaemia and correction of biochemical disturbance is unknown because they usually improve simultaneously. To investigate this, six children (group 2) who already had a mean haemoglobin concentration of 107 g/l while receiving dialysis were followed up for 12 months after successful transplantation. They showed no significant change in haemoglobin concentration, but a dramatic improvement in biochemistry. There was no significant change in cardiovascular function. Anaemia is the more dominant influence on cardiovascular function in end stage renal failure.

Right heart pressure determination by Doppler in infants with tricuspid regurgitation

Doppler and direct measurements of right ventricle to right atrial pressure drop were made during cardiac catheterisation on 28 occasions in 26 infants with congenital heart disease. Age was 10 days to 12 months (median 4.5 months), and weight was 3.1 to 9.0 kg (median 4.7 kg). We measured peak velocity of tricuspid regurgitation by continuous wave Doppler, and the pressure drop was calculated using the modified Bernoulli equation (delta p = 4v2). There was a high correlation (r = 0.95) between direct and Doppler measurements. Doppler values tended to underestimate the right ventricle to right atrial pressure drop, but this was not of clinical significance (mean 2 mm Hg). The 95% confidence interval for the Doppler velocity was -0.41 to +0.26 m/sec, and was consistent across the range of pressures studied. Variability between observers was tested, by two observers performing sequential paired examinations on 16 newborn babies with tricuspid regurgitation. The coefficient of repeatability was 6.3 mm Hg (95% confidence interval 4.7 to 9.5 mm Hg) or 0.26 m/sec (0.18 to 0.50 m/sec). This method of right ventricular pressure estimation, validated previously only in older children and adults, is a reproducible and accurate technique in infants with tricuspid regurgitation.

Cardiac abnormalities in end stage renal failure and anaemia

Thirteen anaemic children on dialysis were assessed to determine the incidence of cardiac changes in end stage renal failure. Nine children had an increased cardiothoracic ratio on radiography. The electrocardiogram was abnormal in every case but no child had left ventricular hypertrophy as assessed by voltage criteria. However, left ventricular hypertrophy, often gross, was found on echocardiography in 12 children and affected the interventricular septum disproportionately. Cardiac index was increased in 10 patients as a result of an increased left ventricular stroke volume rather than heart rate. Left ventricular hypertrophy was significantly greater in those on treatment for hypertension and in those with the highest cardiac index. Abnormal diastolic ventricular function was found in 6/11 children. Children with end stage renal failure have significant cardiac abnormalities that are likely to contribute to the high cardiovascular mortality in this group. Anaemia and hypertension, or its treatment, probably contribute to these changes. Voltage criteria on electrocardiogram are of no value in detecting left ventricular hypertrophy. Echocardiography must be performed, with the results corrected for age and surface area, in order to detect and follow these abnormalities.

Short term correction of anaemia with recombinant human erythropoietin and reduction of cardiac output in end stage renal failure

Children with end stage renal failure and anaemia have an increased cardiac index and often gross ventricular hypertrophy. The contribution of anaemia to these abnormalities is uncertain. Eleven children with end stage renal failure and anaemia (haemoglobin concentration < 90 g/l) were enrolled into a single blind, placebo controlled, crossover study to assess the cardiovascular effects of reversing anaemia using subcutaneous human recombinant erythropoietin (r-HuEpo). Each limb lasted 24 weeks; seven children completed both limbs of the study. Haemoglobin increased with r-HuEpo, remaining above 100 g/l for a mean of 11 weeks. Cardiac index fell as a result of a reduction in both left ventricular stroke volume and heart rate. Left ventricular end diastolic diameter also decreased. In five children left ventricular wall thickness and left ventricular mass decreased with r-HuEpo, but this failed to reach significance for the whole group. Blood pressure did not change in six normotensive children completing an r-HuEpo limb; the decrease in cardiac index was therefore balanced by an increase in peripheral vascular resistance. Three children were taking anti-hypertensive treatment at the start of the study; one required an increase, and one a decrease, in treatment during the r-HuEpo limb. Short term treatment with r-HuEpo reduces cardiac index. A longer study is needed to determine whether this will, in time, result in a significant reduction in left ventricular hypertrophy.

Restrictive endocardial fibroelastosis in a neonate without other cardiac pathology

A case is presented of constrictive endocardial fibroelastosis without other cardiac abnormality in a newborn infant who was treated successfully by orthotopic heart transplantation.

Pulmonary and systemic arterial pressure in hyaline membrane disease

Systolic pulmonary arterial pressure was determined serially over the first 10 days of life in 33 babies with hyaline membrane disease by measuring the peak velocity of pansystolic tricuspid valve regurgitation, using Doppler ultrasound, and applying the Bernoulli equation. Results are presented in age groups 0-12, 13-36, 37-72, and 73-96 hours respectively. The incidence of tricuspid valve regurgitation was 92, 97, 80, and 64% (falling to 35% by day 10) compared with 53, 50, 31, and 0% in 17 healthy premature infants. In comparing healthy babies with those with hyaline membrane disease, no allowance was made for right atrial pressure. The derived 'right ventricle to right atrial (RV-RA) pressure difference', was expressed as a ratio of systemic arterial (systolic) pressure. Over the first three days, this ratio fell much faster in the healthy babies. Values were 0.78:1, 0.77:1, and 0.72:1 in babies with hyaline membrane disease and 0.87:1, 0.53:1, and 0.44:1 in healthy babies. Ductal patency was prolonged in babies with hyaline membrane disease (75% on day 4 compared with 6% in healthy babies). The incidence of bidirectional ductal flow, indicating balanced pulmonary and systemic arterial pressures, was 79, 53, 30, and 20%, and in healthy babies was 41% at 0-12 hours and zero thereafter. Pulmonary arterial pressure was then calculated by adding a right atrial pressure estimate of 5 mm Hg to the RV-RA difference when the babies were ventilated. Babies of lower gestation had lower values. The pulmonary: systemic arterial pressure ratio showed considerable temporal variability, but fell with age and was raised by high mean airway pressure and pneumothorax (through a reduction in systemic pressure), and less noticeably by carbon dioxide tension. It did not correlate significantly with other indices of disease severity. Hyaline membrane disease is associated with delayed postnatal circulatory adaptation characterized by pulmonary hypertension, systemic hypotension, and prolonged ductal patency.

Central venous pressure in the ventilated neonate

As there is no other measurement of right ventricular preload, central venous pressure (CVP) measurement provides unique and important haemodynamic information. CVP is not measured routinely in neonatology and there is a shortage of data in the ventilated neonate. CVP was measured in 62 ventilated neonates. Thirteen had respiratory disorders (28-42 weeks' gestation, birth weight 860-4390 g) and 49 had congenital heart disease (birth weight 1600-4500 g, age 0.5-30 days). Data from other case reports are also presented. In the babies with respiratory distress, a value of zero was associated with clinical evidence of hypovolaemia and negative values, common in the unventilated neonate, did not occur in those who were ventilated. Values over 7 mm Hg were found in babies with evidence of myocardial dysfunction or persistent fetal circulation but were also found with transmitted high intrathoracic pressure, such as with pneumothorax. In the babies with congenital heart disease, values mostly lay between 4 and 8 mm Hg. Values outside this range, particularly above 8 mm Hg, were usually associated with profound metabolic acidosis, suggesting circulatory failure. While the main use of CVP measurement is in trend analysis, this report suggests that single measurements can be of value, though correct interpretation will depend on the context in which they are made.

Aortic coarctation endarteritis and aneurysm: diagnosis by transoesophageal echocardiography

A 17-year-old girl developed infective endarteritis, caused by Staphylococcus aureus, at the site of a previously undiagnosed aortic coarctation. Transoesophageal echocardiography revealed a clinically unsuspected false aneurysm. Foreknowledge of the presence of the aneurysm proved to be life saving when an acute deterioration required emergency surgery.

Non-invasive assessment of pulmonary arterial pressure in healthy neonates

Doppler echocardiograms were carried out on 51 healthy babies three times during the first 72 hours of life to estimate pulmonary arterial systolic pressure by measuring regurgitant tricuspid jet velocity and applying the Bernoulli equation. Tricuspid regurgitation was detected at some stage in all preterm babies and most of those born at full term. Pulmonary arterial pressure could be measured from peak regurgitant velocity in babies with pansystolic regurgitation. The incidence of pansystolic regurgitation among 34 term babies at 0-12, 13-36, and 32-72 hours of age was 22, 27, and 19%, and in 17 preterm babies (within the same age groups) was 53, 50, and 31%, respectively. Estimates of pulmonary artery pressure in the term babies were in accord with known catheter values. Pressure fell rapidly during the first day in all 51 babies. The ratio of pulmonary:systemic arterial pressure was comparable between the two groups throughout. Ductal flow patterns mirrored the fall in this ratio with age--bidirectional flow was associated with a ratio of between 0.88:1 and 1.22:1 and high velocity left to right flow with a ratio of between 0.49:1 and 0.66:1. Both these techniques are noninvasive ways of assessing neonatal pulmonary arterial pressure.

Hemopump support for the failing heart

Under fluoroscopy, the hemopump is passed through the aortic valve into the left ventricle through a Gortex (WF Gore, Denver, CO) chimney sewn to a surgically exposed femoral artery. The system aspirates the left ventricular blood and actively pumps it into the aorta. Five patients (four men, one woman), aged 47-71 years (mean, 62 years), were candidates for hemopump support because of refractory cardiogenic shock. Three were recovering from repeated coronary artery bypass graft (CABG) surgery, and two required postoperative emergency CABG for failed percutaneous transluminal coronary angioplasty (PTCA). One patient died during insertion, and four had the hemo-pump successfully placed. All patients had low cardiac out-put and had intraaortic balloons in place. Average insertion time took 20 min, with maintenance on the hemopump for an average of 13 hr. One patient was maintained on the hemopump for 12 hr, but because of continued deterioration, was placed on a total artificial heart (Harvik 7-70). Patients 3 (hemopump inserted transthoracically) and 4 had the hemopump discontinued because of brain death, and the fifth survived. This patient is alive and working 1 yr later. The hemopump is an effective left ventricular support system that is less invasive than conventional transthoracic systems.

Correction of total anomalous pulmonary venous connection below the diaphragm

Six infants with total anomalous pulmonary venous connection below the diaphragm had correction by modification of conventional surgical technique. Catheterization revealed the confluence of the pulmonary veins draining into a descending vein below the diaphragm. Symptoms of pulmonary venous hypertension and low cardiac output were typical. All had repair with circulatory arrest (average time, 32 minutes). Mobilization of the pulmonary veins and the descending vein is important. The descending vein was transected at the diaphragm. Its anterior surface was incised through the confluence of the pulmonary veins, thus creating an open Y incision. This large Y-shaped vein was anastomosed to the left atrium and carried obliquely to the tip of the left atrial appendage. The anastomosis was fashioned so that the long limb of the Y rotated anteriorly and superiorly to substantially enlarge the left atrium, making the total diameter of the anastomosis larger than the mitral valve orifice. This simplified the surgical repair and allowed direct suture closure of the atrial septal defect in all patients, as the left atrial size was at least doubled. No postoperative complications occurred, and the patients were discharged an average of 4.2 days postoperatively. Restudy at an average of 3.5 years revealed normal pressures and normal architecture by angiography. Use of the descending vein as an integral part of the reconstruction and enlargement of the left atrium was the major technical factor leading to a successful outcome in these patients and eliminating a patch or transposition of the atrial septum.

Towards the evaluation of natural resource management projects in the sahel

Recent drought in the Sahel has focussed attention on the important role played by natural resources in the rural economy and, together with the increasing environmental awareness of donors, has spawned a series of field projects aimed at improving the management of existing natural resources. This paper is a working document; a contribution to the discussion of how to evaluate the success or failure of natural resource management projects and of whether important components of successful projects can be replicated elsewhere.

Disrupted coronary artery caused by angioplasty: supportive and surgical considerations

Of 2,859 patients having percutaneous transluminal coronary angioplasty, 201 (7%) underwent emergency coronary artery bypass grafting. Two categories of patients were reviewed. Group 1 consisted of 126 patients of 2,304 who had immediate coronary artery bypass grafting after failed elective percutaneous transluminal coronary angioplasty. Ninety-eight of these patients had angiographic evidence of occlusion of a coronary artery, and 28 had angiographic evidence of coronary artery dissection. Epicardial hemorrhage was observed at operation in 20% (25 patients). Three deaths (2.4%) occurred in group 1, and an average of 3.3 grafts was performed per patient. Group 2 comprised 75 of 555 patients who had unsuccessful attempted percutaneous transluminal coronary angioplasty during an evolving myocardial infarction and required immediate coronary artery bypass grafting. Angiography revealed coronary artery occlusion in 61 patients with dissection in 14. All group 2 patients had evidence of myocardial injury by electrocardiographic and enzymatic (myocardial-specific isoenzyme of creatine kinase) criteria. Three deaths (4%) occurred in this group, and there was an average of 3.4 grafts per patient. Percutaneous transluminal coronary angioplasty is routinely performed without surgical consultation, although an operating room and team are usually available. Supportive techniques include the intraaortic balloon pump and percutaneous cardiopulmonary bypass. In those patients with coronary artery dissection, care must be taken to reestablish the true lumen of the coronary artery. Hemopericardium should be surgically explored and broken guidewires or other foreign bodies or debris removed. From 1979 through 1986, the number of patients requiring emergency coronary artery bypass grafting after percutaneous transluminal coronary angioplasty steadily declined to less than 5%.

Permanent left ventricular assistance for outpatients through surgical implantation of a modified intra-aortic balloon pump

There is a large population of patients in end-stage congestive heart failure who cannot be treated by means of conventional cardiac surgery, cardiac transplantation, or chronic catecholamine infusions. In 2 such patients, we provided permanent left ventricular assistance on an outpatient basis by surgically implanting a modified intra-aortic balloon pump. A Dacron-velour graft to the common iliac artery served as a covering for the extravascular portion of the balloon's pneumatic tubing, which was stabilized by routing it through the iliac crest. The tubing was then carried ventrally to exit through a stoma just above the inguinal ligament. Before hospital discharge, each patient underwent a 5-day regimen of alternate pumping and ambulation. The patient was then permitted to go home, but returned daily as an outpatient in accordance with individual need, for approximately 6 hours of hemodynamic support. The 1st patient lived 3 months after pump insertion, and the 2nd patient for 38 days. Although the 1st patient developed a fever of unknown origin that prompted us to remove the intra-aortic balloon pump unnecessarily, there was no evidence of infection upon surgical exploration and subsequent tissue culturing; she died, rather, of intractable ventricular fibrillation, apparently consequent to her 36-hour loss of hemodynamic support. The 2nd patient also died of a cause unrelated to the presence of the pump, and on autopsy showed good evidence of healing and absence of infection. On the evidence of this pilot study, we conclude that intermittent left ventricular assistance, through periodic activation of a permanently implanted intra-aortic balloon pump during outpatient visits, warrants further study as an alternative for selected patients with end-stage heart disease, when medical and other surgical options have been exhausted.

Percutaneous cardiopulmonary bypass: application and indication for use

Percutaneous cardiopulmonary bypass (CPB) was used in 22 patients: 7 patients with cardiac arrest due to acute myocardial infarction; 4 patients in cardiac arrest because of failed angioplasty; 1 patient for high-risk elective angioplasty; 1 patient with massive pulmonary emboli; 2 patients with hypothermia; 2 pediatric patients (1 with sepsis and 1 in combination with extracorporeal membrane oxygenator support); 1 patient with refractory arrhythmia; and 4 patients with trauma. Percutaneous CPB involves a modified Seldinger technique that is easily applied. All patients except those with massive trauma were resuscitated with the use of percutaneous CPB. One patient requiring a very difficult proposed angioplasty received percutaneous CPB support while triple-vessel angioplasty was performed. Percutaneous CPB appears to be beneficial in resuscitating patients with refractory cardiac arrest or other forms of circulatory collapse except trauma. Limited use for brief periods in high-risk patients having elective angioplasty might be applicable.

Internal mammary artery versus saphenous vein graft to the left anterior descending coronary artery: prospective randomized study with 10-year follow-up

In 1975, 80 patients undergoing revascularization were prospectively randomized to receive either a greater saphenous vein (SV) graft (41 patients, Group 1) or a left internal mammary artery (LIMA) graft (39 patients, Group 2) to the left anterior descending coronary artery (LAD). All patients were completely revascularized. The average number of grafts per patient in both groups was 3.2. Patients were followed 10 years; follow-up was 97.5% complete. Group 1 and Group 2 were compared in regard to mortality, treadmill response, myocardial infarction, reoperation, percutaneous transluminal coronary angioplasty, and return to work. Mortality in Group 1 was 17.9% versus 7.7% in Group 2 (p less than 0.05). Treadmill studies were positive in 17 Group 1 patients and 7 Group 2 patients (p less than 0.05). Myocardial infarctions occurred in 8 patients in Group 1 versus 3 in Group 2. The number of reoperations was 2 in Group 1 versus 1 in Group 2. Percutaneous transluminal coronary angioplasty was performed in 3 patients in Group 1 and 2 in Group 2. Repeat studies revealed 76.3% patency of the SV graft to the LAD (Group 1) and 94.6% patency of the LIMA graft to the LAD (Group 2). Cardiac-related mortality in Group 1 was 12.8% at 10 years (5 patients) versus 7.7% in Group 2 (3 patients). Based on this study, the IMA is a superior conduit for bypass to the LAD.

Bridging circulatory support before heart transplant without invasion of the mediastinum

Heart transplantation is becoming a useful tool in the clinical treatment of patients with end-stage cardiac decompensation. Donor organs are not always available at a critical time for a patient waiting for a transplant. Bridging techniques have been described that use mechanical support systems. This article describes the use of femoral-venous to femoral-arterial bypass over a period of 50 hours in a 38-year-old woman waiting for a donor heart. Because the patient sustained cardiopulmonary arrest before organ availability, mechanical circulatory support that used femoral-venous to femoral-arterial bypass was instituted. The patient's own lungs were used as an oxygenator. Pump flow levels were determined by the level of central aortic oxygen saturation. Successful transplant was performed, and bridging, therefore, was done without invasion of the mediastinum.

Characteristics of drug abusers that discriminate needle-sharers

To identify variables that discriminate needle-sharing among drug abusers, 224 male drug abusers were studied. They had been admitted to a 30-day inpatient drug treatment program over a 19-month period (September 1983 through March 1985). The variables examined were divided into three categories: demographic (age, race, education), personality (Minnesota Multiphasic Personality Inventory [MMPI] scores and MMPI deviant scores), and drug use patterns (drug of choice, use of single or multiple [mixed] drugs, severity of drug use, and place of use). Three variables were identified that discriminated needle-sharers from other drug abusers. Compared with other drug abusers, needle-sharers used more multiple drugs, were more likely to use a "shooting gallery," and had more problems related to drug use. No demographic or personality variables discriminated needle-sharers from nonsharers. The data suggested that needle-sharing is widespread in the drug culture. Needle-sharing was not confined to a particular racial group, educational level, or personality type. These findings can be used to structure education programs about acquired immunodeficiency syndrome (AIDS) for drug abusers. Drug treatment programs appear to provide an important opportunity to educate drug abusers about AIDS and related health issues associated with needle-sharing.

Reperfusion protocol and results in 738 patients with evolving myocardial infarction

Reperfusion is an accepted therapy for evolving myocardial infarction (MI), as successful reperfusion reduces morbidity and mortality. A team approach between the cardiologists and cardiac surgeons must be applied to achieve reperfusion within a finite time from the onset of coronary thrombosis. Analysis of 738 patients grouped them by successful reperfusion in the catheterization laboratory versus the operating room. Factors that predict wall motion recovery related to the onset of clinical symptoms, time to reperfusion, coronary anatomy, and collateral network were reviewed. Comparisons were made between patients with stable versus unstable hemodynamics and successful or unsuccessful reperfusion. Of the 738 patients, the initial attempt at reperfusion was made in the catheterization laboratory with success in 331. These patients all had primarily single-vessel disease. With multiple-vessel disease identified at catheterization, 189 patients were immediately treated by surgical reperfusion. This method also was used for an additional 72 patients in whom reperfusion could not be achieved in the catheterization laboratory. Of the entire group of 738 patients, 146 (20%) could not be reperfused. Overall mortality for the 592 patients reperfused was 4.9% compared with 17% for those who could not be reperfused. Time was critical for wall motion recovery if no collaterals were demonstrated on angiography. If collaterals were present, time to reperfusion was not critical. Wall motion recovered in 90% of the patients if the endocardial anatomy on the initial angiogram was smooth. However, if the endocardial anatomy looked mottled and irregular, less than 10% of patients had recovery of wall motion.(ABSTRACT TRUNCATED AT 250 WORDS)