Inter- and intraobserver variability in LVH and RVH reporting in pediatric ECGs.

BACKGROUND: Physicians' diagnoses are often used as the gold standard for evaluating computer electrocardiogram (ECG) interpretation programs. As part of a larger study to evaluate the Glasgow pediatric ECG analysis program, inter- and intraobserver variability in the ECG reporting of two pediatric cardiologists was examined. METHODS: The ECGs of 984 children were sent for reporting independently by two cardiologists with all identifying information except age and sex removed. Three hundred twenty ECGs had no clinical indication available, and they were thus reported "blind." For 664 ECGs, the clinical indication was known and included with the ECG trace. All ECGs reported as right ventricular hypertrophy (RVH) or left ventricular hypertrophy (LVH) were returned to the cardiologists without their knowledge for reporting a second time "blind" as to the clinical indication. RESULTS: When the cardiologists' reports were compared with each other, the provision of clinical information led to greater agreement between them for the diagnosis of LVH (kappa increased from 0.44 to 0.52) but did not substantially affect their agreement in diagnosing RVH (kappa fell from 0.66 to 0.63). Intraindividual comparisons in 166 ECGs revealed that one cardiologist was more consistent in diagnosing RVH and the other more consistent in diagnosing LVH. CONCLUSIONS: This study has demonstrated the difficulties in using cardiologists' diagnoses as the gold standard with which to evaluate pediatric ECGs.

Evaluation of pediatric electrocardiogram diagnosis of ventricular hypertrophy by computer program compared with cardiologists.

This study aimed to evaluate the diagnosis of pediatric left ventricular hypertrophy (LVH) and right ventricular hypertrophy (RVH) by the Glasgow electrocardiogram (ECG) interpretation program compared to interpretations provided by two pediatric cardiologists. ECGs had all identifying information removed and were sent to the cardiologists independently with the patient's age and sex and the clinical indication for the ECG, if known. A total of 984 ECGs were included in the study, of which 664 were reported "with clinical indication" and 320 were reported "blind." With respect to an averaged diagnosis of the two cardiologists, the sensitivity of the program for RVH was better when the cardiologists reported blind (73.3%) than with the clinical indication (53.5%), with the same trend for the program compared with individual cardiologists. The specificity of the program was at least 94.4% in all cases. For LVH, the program had high specificity (=95.8%) for "reported blind" and "with clinical indication" cases but low sensitivities throughout (the highest was 44.4% with respect to an averaged diagnosis of the two cardiologists reporting with the clinical indication). Subsequent discussion revealed that if the cardiologists had disagreed with one another initially, their consensus opinion was twice as likely to be in agreement with the program.

The outcome of idiopathic dilated cardiomyopathy and myocarditis in children from the west of Scotland.

We analysed retrospectively all infants and children with idiopathic dilated cardiomyopathy (IDC) and myocarditis at the Regional Cardiac Centre of the Royal Hospital for Sick Children, Glasgow, during 1980-1997. Among the 39 patients with IDC, 25 (64%) were infants aged < 1 year, eight (20.5%) had wheezing as the presenting symptom, and only six (15%) had a significant cardiac murmur. Thirty-eight of thirty-nine patients diagnosed in life were followed-up for 1 day to 15 years (median 3 years). Twelve of the thirty-nine (31%) died, six deaths were within a week of presentation and the rest within a year. The survival at 1 year and at 12 years was 0.69 (95% CI 0.54 to 0.84). Fourteen patients had histologically proven myocarditis, and all 9/14 (64%) detected at post-mortem and one of the five diagnosed in life died. Patients with myocarditis exhibited an actuarial survival of 0.29 (95% CI 0.04 to 0.53) at 1 year and at 9 years, significantly lower than IDC patients (log rank 9.8, P < 0.01). There was no difference in the outcome for patients with positive or negative Coxsackie titres or who presented in the 1980s and in the 1990s. No risk factor that independently influenced the outcome or survival could be identified in either group. Thus our study from a relatively well-defined population of the west of Scotland showed that a significant proportion of children with IDC and myocarditis died in the first week of illness and that patients with myocarditis had shorter survival.

Interventional treatment of lateral tunnel dehiscence in a total cavopulmonary connection using a balloon expandable covered stent.

In this paper we present a patient with dehiscence of an intra-atrial tunnel previously constructed during a total cavopulmonary connection procedure. We describe the use of a custom made covered stent to seal off the dehisced segment, and abolish the intra-cardiac shunting. We believe this is the first account of such a procedure being undertaken.

Transhepatic approach for cardiac catheterisation in children: initial experience.

AIM: To assess initial experience of cardiac catheterisation in children by the transhepatic approach where conventional venous access is impossible. PATIENTS AND METHODS: Percutaneous transhepatic cardiac catheterisation was performed on six occasions in five children (three male) aged 4 to 36 months (mean 17 months). All children had documented femoral venous occlusion and all but one had occlusion of the superior vena cava. Ultrasound was used in five of the six procedures to help identify a large hepatic vein. A 4 F or 5 F sheath was introduced into the vein using the Seldinger technique. In the fourth patient, hepatic venous access was obtained immediately without the assistance of ultrasound. RESULTS: Percutaneous transhepatic catheterisation was successfully performed at all six attempts. Total procedure time ranged from 120 to 200 minutes (mean 138 minutes) and screening time from 14 to 22 minutes (mean 16.8 minutes). A serious complication was encountered in only one patient who had a retroperitoneal bleed after administration of thrombolysis for loss of femoral arterial pulse. CONCLUSIONS: The percutaneous transhepatic technique can provide a safe alternative approach for cardiac catheterisation in children with multiple venous occlusion. The procedure can be performed very simply using the Seldinger technique and equipment normally used for conventional venous cannulation for cardiac catheterisation.

Reduced heart rate variability following repair of tetralogy of Fallot.

OBJECTIVE: To examine autonomic function as assessed by heart rate variability in patients 10 or more years after repair of tetralogy of Fallot, and to relate this to cardiac structure, function, and electrocardiographic indices. METHODS: Heart rate variability was measured by standard time domain techniques on a 24 hour Holter ECG in 28 patients, aged 12 to 34 years (mean 19.5), who had undergone repair of tetralogy of Fallot at least 10 years previously. Echocardiography was performed to assess left ventricular size and function, right ventricular size and pressure, and any proximal pulmonary arterial stenosis. Right ventricular function was evaluated by radionuclide scan. QRS duration, QT interval, and QT dispersion were measured on a standard 12 lead ECG. Measurements of heart rate variability were compared with values from 28 age matched healthy controls (mean age 19.9 years). Interrelations between variables were assessed using Pearson correlation coefficients and stepwise regression analysis. RESULTS: Heart rate variability was reduced, compared with values for age matched normal controls, in 12 of the 28 patients. Reduced heart rate variability was associated with increased age, increased right ventricular size and pressure, and widening of the QRS complex. CONCLUSIONS: Reduced heart rate variability is a feature following repair of tetralogy of Fallot. It is associated with increasing age, impaired right ventricular haemodynamics, and widening of the QRS complex. Under these circumstances, reduced heart rate variability may be a marker for deteriorating right ventricular function. Increased QRS duration has been identified as a risk factor for sudden death following repair of tetralogy of Fallot, and impaired cardiac autonomic control may be one of the mechanisms involved.

1:1 atrioventricular conduction in congenital complete heart block.

A female neonate with congenital complete heart block developed atrioventricular conduction through an accessory pathway. Despite sinus rhythm and an adequate heart rate she developed severe dilated cardiomyopathy and died at age 14 months. This case illustrates that underlying heart block can be present in individuals with asymptomatic Wolff-Parkinson-White syndrome and that the dilated cardiomyopathy that occasionally accompanies autoimmune congenital heart block is not primarily caused by bradycardia.

Closure of Blalock-Taussig shunts using a new detachable coil device.

Two children underwent interventional closure of a modified Blalock-Taussig shunt using a new detachable coil system (Duct-Occlud). This procedure has advantages over currently available materials to occlude these and other communications between the systemic and pulmonary circulations.

Age and body surface area related normal upper and lower limits of M mode echocardiographic measurements and left ventricular volume and mass from infancy to early adulthood.

BACKGROUND: M Mode echocardiograms can be measured by two different conventions. In addition, normal limits of echocardiographic measurements have customarily been stratified according to age or body surface area. There is therefore a need to develop a more easily managed approach to calculating normal limits of measurements for the two conventions, one of which, the Penn convention, has not previously been used for echocardiographic measurements in children. METHODS: M mode echocardiograms were recorded in 127 healthy subjects aged from 7 months to 19.5 years. Measurements were made from paper recordings according to the recommendations of the American Society of Echocardiographers and those of the Penn convention. RESULTS: Age and body surface area were found to be highly correlated; but for completeness separate age dependent and body surface area dependent equations for the normal limits of M mode echocardiographic variables were developed. CONCLUSION: A set of age dependent equations and a set of body surface area dependent equations are presented for easy calculation of upper and lower limits of normal M mode echocardiographic variables in infants and children.

Intermittent ductal patency in healthy newborn infants: demonstration by colour Doppler flow mapping.

Colour Doppler flow mapping was used to determine the time of closure of the arterial duct in 51 healthy newborn infants. Initial time of closure corresponded with previous reports: 20% on the first day, 82% by the second day, 96% by the third day, and 100% by the fourth day. Twenty infants were delivered by caesarean section and followed up for seven days even if the duct had apparently closed; in six intermittent patency was demonstrated with flow in the third, fourth or fifth day, although earlier functional closure had been observed. All were found to be closed on the sixth and seventh days. It is necessary to be aware of the phenomenon of intermittent closure in any study determining or assessing the effect of any intervention on ductal patency.

Protein C activity in severely ill newborns with congenital heart disease.

Levels of protein C functional activity were studied in twenty-nine full-term infants with symptomatic congenital heart disease, who presented in the neonatal period. Protein C levels on admission ranged from < 10% to 61% (mean 37.7% S. D. 14.1%). Eight of the twenty-nine babies had protein C levels between 1.5 and > 3.0 S. D. below the normal neonatal mean with no parental evidence of familial deficiency. Of these infants with low protein C two developed thrombotic complications and four had evidence of coagulation factor consumption. Critically ill infants were over-represented in the group with low protein C. Severely ill newborn infants with protein C at or below the lower limit of the normal neonatal range may be at increased risk of either a consumptive coagulopathy or major thrombosis.

Electrocardiographic changes during cesarean section under regional anesthesia.

To determine electrocardiographic changes and whether myocardial ischemia occurs during cesarean section, electrocardiograms were recorded continuously using Holter monitoring in 25 patients undergoing elective cesarean section under either spinal or epidural anesthesia. In addition, in 13 of the patients, two-dimensional precordial echocardiography was carried out before and during cesarean section. ST segment depression suggestive of myocardial ischemia occurred in 16 patients including 8 of the 13 with echocardiograms. Wall motion remained entirely normal during episodes of ST segment depression. Patients in whom ST depression developed had significantly more rapid heart rates at delivery than those who did not experience ST depression. We conclude that ST segment depression is a common feature of the electrocardiogram during cesarean section under regional anesthesia and is not the result of myocardial ischemia.

Transoesophageal echocardiographic assessment of fixed subaortic obstruction in children.

OBJECTIVE: To evaluate the clinical usefulness of transoesophageal echocardiography in the assessment of children with fixed left ventricular outflow tract stenosis. PATIENTS AND METHODS: Eight consecutive children, aged over 5 years, with fixed subaortic stenosis and one child with fixed subpulmonary left ventricular outflow tract stenosis were prospectively assessed by precordial and transoesophageal echocardiography. RESULTS: Transoesophageal images of the left ventricular outflow tract were much clearer than precordial images in all patients except one with a prosthetic mitral valve. Improved visualisation provided further information on the nature of the lesion (additional chordal attachment of the mitral valve in one, accessory atrioventricular valve tissue with aneurysm formation in one), on the extent of the lesion (circumferential in three), and on the very close relation of a ridge to the aortic valve leaflets in one. Transoesophageal Doppler did not provide any additional information on aortic regurgitation and was unreliable for gradient estimation across the left ventricular outflow tract. CONCLUSIONS: Transoesophageal imaging provides an excellent means of visualising lesions in the left ventricular outflow tract and can be useful in a few children and adolescents in whom precordial echocardiography does not provide adequate information. The technique can also be used intraoperatively to define the full extent of the obstructive lesion and to assess residual lesions after surgery.

Influence of colour Doppler echocardiography on the ultrasonic assessment of congenital heart disease: a prospective study.

OBJECTIVE: To evaluate the additional information provided by colour Doppler in the ultrasonic assessment of congenital heart disease. PATIENTS AND METHODS: A prospective study of 215 children (age range 1 day-16 years) presenting with clinical signs of congenital heart disease. RESULTS: Colour Doppler was essential for the diagnosis of an anomalous left coronary artery and altered the management of a patient initially diagnosed as having cardiomyopathy. Colour Doppler provided extra information, but without major impact on management, in the following: the diagnosis of ventricular septal defects associated with other defects, of multiple ventricular septal defects, of anomalous pulmonary venous drainage, and of mild mitral regurgitation; the demonstration of site of coarctation, of stenotic or hypoplastic pulmonary artery branches, of unobstructed flow through a right atrial membrane, and of left ventricle to right atrium regurgitation; the assessment of the width of the duct and of flow through the patent foramen ovale in transposition and tricuspid atresia; the differentiation of pulmonary atresia from critical pulmonary stenosis and the measurement of maximum velocity of tricuspid regurgitation. CONCLUSIONS: Ideally all patients should undergo colour Doppler studies before cardiac surgery to ensure a more accurate diagnosis. However, since the additional information provided does not affect the management in most patients, machines without colour Doppler can provide a satisfactory service in paediatric cardiology centres in countries where resources are limited.

Transoesophageal echocardiographic assessment of primum, secundum and sinus venosus atrial septal defects.

We compared the ability of transthoracic and transoesophageal echocardiography to determine the presence and site of an atrial septal defect and associated anomalous pulmonary venous connexions in 13 school age children (aged 5 to 15 years) and 12 adults (aged 25 to 68 years). Transthoracic echocardiography detected atrial septal defects in 12 children and 6 adults. Transoesophageal echocardiography confirmed the position of 16 (13 secundum, 3 primum) of these 18 defects but altered the diagnosis from a secundum defect to a sinus venosus defect in one and from a sinus venosus defect to a high secundum defect in another. In addition to these 18, transoesophageal echocardiography diagnosed a defect in 5 adults (3 secundum and 2 sinus venosus defects) and 1 child (secundum defect). In an adult with inconclusive transthoracic findings, transoesophageal echocardiography enabled clear visualisation of the atrial septum and excluded an atrial septal defect. Transoesophageal echocardiography showed anomalous attachment of a pulmonary vein into the region of a sinus venosus defect (n = 3) but did not show anomalous connexions to the superior caval vein (n = 3) or the inferior caval vein (n = 1). Transoesophageal echocardiography provides a reliable method of diagnosing or excluding an atrial septal defect in patients with inconclusive transthoracic findings and is of particular diagnostic value in sinus venosus defects.

Diagnosis of mitral valve aneurysm by transoesophageal echocardiography.

In a patient with mitral valve aneurysm precordial echocardiography suggested a mistaken diagnosis of infective endocarditis. Transoesophageal echocardiographic examination established the correct diagnosis, which was subsequently confirmed at operation. Transoesophageal echocardiography gives better resolution of lesions associated with the mitral valve than precordial examination and may improve the diagnostic accuracy.

Balloon atrial septostomy under echocardiographic control: six years' experience and evaluation of the practicability of cannulation via the umbilical vein.

Balloon atrial septostomy was undertaken under cross sectional echocardiographic control in 63 consecutive infants: in no case was fluoroscopic imaging required. The procedure was performed in the cardiac catheterisation laboratory, ward side room, or at the bedside in the neonatal intensive care unit. Catheterisation via the umbilical vein was attempted in 37 infants aged less than 48 hours old and was successful in 27. No complication was clearly attributable to the procedure though two infants died. A nine day old child died from disseminated intravascular coagulation the day after septostomy by the iliofemoral route and another, aged nine days, died of necrotising enterocolitis which had developed when he was eight days old, after umbilical catheterisation at eight hours. Balloon atrial septostomy is a safe and easy procedure under cross sectional echocardiographic imaging control. Catheterisation via the umbilical vein was safe, easy to perform, and is appropriate in infants aged less than 48 hours.

Doppler ultrasound and the silent ductus arteriosus.

A clinically undetectable, small ductus arteriosus was identified by Doppler ultrasonography in 21 individuals. Infants were excluded from the study and no patient had pulmonary hypertension. Persistence of the ductus arteriosus is likely to be more common than shown by less sensitive diagnostic methods. Some patients considered to have infective endocarditis with a normal heart may have a silent ductus arteriosus. Evidence of such an association would justify ligation or antibiotic cover as prophylactic measures.