Michael E. C. Blackburn

Laser valvotomy with balloon valvoplasty for pulmonary atresia with intact ventricular septum: five years' experience.

OBJECTIVE: To assess immediate and medium term results of transcatheter laser valvotomy with balloon valvoplasty in selected infants with pulmonary atresia and intact ventricular septum. DESIGN: Prospective study. SETTING: Tertiary cardiac unit. PATIENTS: All infants with pulmonary atresia and intact septum with no more than minor tricuspid valve hypoplasia referred between November 1990 and June 1995. Laser valvotomy was attempted in nine infants of median age 4-5 days and median weight 3.6 kg. INTERVENTION: The pulmonary valve was perforated using a 0.018 inch fibreoptic guidewire attached to a NdYag laser and introduced through a catheter positioned beneath the valve. After perforation the valve was dilated with progressively larger balloons. MAIN OUTCOME MEASURES: Successful laser valvotomy and balloon dilatation, complications, pulse oximetry, right ventricular outflow velocities, and need for surgical treatment. RESULTS: Valvotomy was successful in all but one case, the failure being due to laser breakdown. After perforation the valve was dilated to 6-8 mm diameter. Prostaglandin E was withdrawn immediately in six of the eight duct dependent infants, and 28 and 49 days later in two. No patient required an aortopulmonary shunt. Two patients had repeat valvoplasty at 20 days and three months of age, respectively; one required infundibular resection and closure of the atrial septum at age four and one is awaiting similar treatment. CONCLUSIONS: Laser valvotomy with balloon valvoplasty is safe and effective treatment for selected patients with pulmonary atresia and intact ventricular septum and should be considered as first line treatment in place of surgical valvotomy.

Right ventricular outflow stent implantation: an alternative to palliative surgical relief of infundibular pulmonary stenosis.

OBJECTIVE: Preliminary assessment of the use of stents for palliative relief of right ventricular infundibular stenosis as an alternative to palliative surgical ventricular outflow enlargement. DESIGN: Descriptive clinical study. PATIENTS: Four patients with right ventricular outflow obstruction, aged between 2 and 15 years. One had had previous palliative surgery for pulmonary atresia, one had hypoplastic pulmonary arteries after palliative surgery for tetralogy of Fallot, one had multiple congenital abnormalities, and one had hypertrophic cardiomyopathy. SETTING: Tertiary paediatric cardiac centre. METHODS: After initial echocardiographic diagnosis the extent of right ventricular outflow obstruction was assessed by angiography. Balloon expandable stainless steel stents (Johnson & Johnson) were deployed in the right ventricular infundibulum. MAIN OUTCOME MEASURES: Improvement in right ventricular outflow assessed by ventriculography and change in right ventricular/ left ventricular pressure ratio, change in systemic oxygen saturation, freedom from arrhythmias, and sustained improvement in echocardiographic indices of obstruction. RESULTS: Mean right to left ventricular pressure ratio fell from 0.95 to 0.35 in the three patients with intact ventricular septum. Oxygen saturation increased from 76% to 91% in the patient with tetralogy. No arrhythmias were detected. Improvement was maintained at mean follow up of 9.7 months in three cases, but one patient required stent enlargement 17 months later because of neoendothelial proliferation within the stent. CONCLUSION: Stent implantation provides an effective alternative to palliative surgical enlargement of the right ventricular infundibulum. Neoendothelial proliferation causes reduction in lumen in some cases, but this may respond to redilatation.

Implantable cardioverter-defibrillator therapy in adult patients with tetralogy of Fallot

AIMS Adults with repaired tetralogy of Fallot (TOF) are at risk of sudden cardiac death (SCD). ESC and AHA guidelines suggest the use of implantable cardioverter defibrillators (ICDs) to protect from this. Few data are available on the benefits of these devices in this population, and there are no randomized studies. METHODS AND RESULTS We analysed outcomes with respect to death, ICD therapy delivery, and complications for 20 patients with repaired TOF and 39 dilated cardiomyopathy (DCM) patients followed up at a UK teaching hospital. All TOF patients had clinical ventricular tachycardia (VT), electrophysiological study-inducible VT, or previous arrest due to tachyarrhythmia and received dual-chamber devices with individualized atrial detection algorithms. Tetralogy of Fallot patients were younger than DCM patients, but follow-up duration was not different between the groups. Tetralogy of Fallot patients were more likely to have experienced oversensing (45 vs. 13%; P < 0.02), inappropriate anti-tachycardia pacing delivery (20 vs. 2%; P < 0.05), and inappropriate cardioversion (25 vs. 4%; P = 0.06) than DCM patients and less likely to receive appropriate therapies than DCM patients. The death rate in TOF patients was significantly lower than that in DCM patients (5 vs. 21%; P < 0.05). CONCLUSION Tetralogy of Fallot patients have a higher risk of inappropriate therapies and other complications yet a lower incidence of appropriate therapies from their ICD than DCM patients. Further research into identification of factors predicting SCD in TOF and the benefits of ICD implantation is essential given the potential complications of ICD implantation in young congenital heart disease patients.

Recommendations for the use of palivizumab as prophylaxis against respiratory syncytial virus in infants with congenital cardiac disease

New data are emerging on the use of palivizumab as prophylaxis against infection with the respiratory syncytial virus in infants with congenital cardiac disease. Following a 4-year multicentre randomised trial, it was shown that prophylactic injections with palivizumab were effective and safe for such children. Prophylaxis consists of 5, monthly, intramuscular injections of palivizumab, at a dose of 15 mg/kg, given during the season for infection with the respiratory syncytial virus. Timing is at the discretion of the physician, depending on the onset of the season locally. It is suggested that, in the United Kingdom, this should be commenced in mid-September. To help clinicians to identify appropriate candidates for palivizumab, a working group of the British Paediatric Cardiac Association has developed recommendations. Infants, namely those under 1 year old, with congenital cardiac disease likely to benefit from prophylaxis include those with haemodynamically significant lesions, particularly increased pulmonary blood flow with or without cyanosis; pulmonary venous congestion, pulmonary hypertension or long-term pulmonary complications, residual haemodynamic abnormalities following medical or surgical intervention (patients who have undergone cardiopulmonary bypass should receive an injection as soon as they are medically stable), cardiomyopathy requiring treatment, and congenital cardiac disease likely to need hospital admission for medical or surgical intervention during the season of infection with the virus. Prophylaxis with palivizumab may also be indicated, at the discretion of the physician, in some children with complex cardiac disease over the age of 1 year. Children less likely to benefit from prophylaxis are those with haemodynamically insignificant disease, or those with lesions adequately corrected by medical or surgical intervention.

New outpatient referrals to a tertiary paediatric cardiac centre: evidence of increasing workload and evolving patterns of referral

OBJECTIVES To assess the volume and range of diagnosis in new patients referred to paediatric cardiac outpatient clinics. METHODS Data was collected prospectively, using a proforma completed at all outpatient clinics over a period of three months. RESULTS There were 526 new referrals, representing an increase of almost one-fifth compared to 5 years ago. Of the referrals, 78 percent came from hospital doctors, and 22 percent from general practitioners, with 221 of those referred being infants. A heart murmur was the most common reason for referral, representing almost two-thirds of cases. In 372 patients referred (71 percent), the heart was discovered to be structurally normal. The proportion of patients with normal hearts referred by general practitioners and hospital doctors were 81 percent, and 68 percent, respectively (p less than 0.004). There was considerable variation in the pattern of referral between doctors working in different hospitals. CONCLUSION New referrals to centres dealing with congenital cardiac malformations are increasing alarmingly, with the majority of the children referred having normal hearts. This increase in demand for specialist services has important implications for resources and training.

Haemolysis following implantation of duct occlusion coils

Objectives To describe the incidence and management of haemolysis after transcatheter coil occlusion of the arterial duct. Design Prospective clinical and echocardiographic follow up of patients who have undergone implantation of the Cook detachable duct occlusion coil. Setting Tertiary paediatric cardiac centre. Patients Five cases of haemolysis (two girls aged 6 and 11 months; three boys aged 6, 17, and 14 months) from a series of 137 duct coil implantations. Main outcome measures The occurrence of clinically significant haemolysis after implantation of duct occlusion coils and resolution of haematuria after completion of duct occlusion. Results Haemolysis was detected in five of 137 procedures following implantation of Cook detachable duct coils. Four patients became symptomatic 12 hours after the procedure but in one haemolysis was detected three months later. Resolution of ongoing haemolysis was achieved within 48 hours of detection with further coil implantations, but haematuria persisted for up to 10 days. In one patient the extensive destruction of erythrocytes resulted in acute renal failure requiring peritoneal dialysis. Conclusions Haemolysis is an important complication after duct coil implantation. It occurred in 3.6% of 137 procedures in this series and is most likely to occur in young patients with relatively large ducts. Further coil implantation to occlude the duct completely is not only successful but technically relatively straightforward and should be undertaken early if major complications such as severe anaemia and renal failure are to be avoided.

Stenting of stenosed aortopulmonary collaterals: a new approach to palliation in pulmonary atresia with multifocal aortopulmonary blood supply.

A patient with complex pulmonary atresia and increasing cyanosis due to stenoses of aortopulmonary collateral vessels improved after implantation of balloon expandable stents into the stenosed vessels. Stent implantation may provide an alternative to surgical palliation in this group of patients.

Transeosophageal echocardiography in neonates, infants and children: applicability and diagnostic value in everyday practice of a cardiothoracic unit

Objective—To determine the applicability of and information obtained by transeosophageal echocardiography in neonates, infants, and children in every day practice of a cardiothoracic unit. Design—Four month prospective study. Setting—Supraregional centre for paediatric cardiothoracic services. Patients and methods—58 patients aged between four days and 16 years with a wide range of cardiovascular disease underwent transoesophageal echocardiography under sedation or general anaesthetic. One of two paediatric probes (6 or 7 mm diameter), or an adult probe (13 mm in diameter) was used. Whenever possible the investigation was immediately preceded by precordial echocardiography. Main outcome measures—Success, failure, technical difficulties, and complications of probe introduction and, when possible, comparison of the information obtained with that obtained from precordial echocardiography. Results—Introduction of the probe was successful in 57 of the 58 patients. The only complication encountered was transient bradycardia during manipulation of the probe in a 2·2 kg baby. The adult (13 mm) probe was successfully used in children as small as 7·0 kg. Below this weight a smaller paediatric probe was required. In 56% of cases transoesophageal ultrasound provided information not obtained from the precordial approach. The technique was of particular value perioperatively and in the immediate postoperative period in neonates and infants and in the presence of valve prostheses and the investigation of mediastinal tumours in older children. Conclusions—Transoesophageal echocardiography is a valuable additional investigative tool for children of all ages. It is of particular value when aquisition of precordial image is impaired around the time of and after operation and in children with prosthetic valves or mediastinal tumour. Image quality was superior with the adult probe and we recommend the use of this probe unless the patients weight is below 7 kg, when a paediatric probe allows this technique to be used usefully and safely in babies as small as 2·2 kg.

Dystrophic calcification of the fetal myocardium.

Intramural cardiac masses were detected antenatally in three fetuses by echocardiography. The masses were initially thought to be rhabdomyomas. All three pregnancies were terminated and histology showed dystrophic calcification in all, with no evidence of tumour. Therefore, dystrophic calcification of the fetal myocardium may have a similar appearance to single or multiple rhabdomyomas. This should be considered when counselling parents after detection of masses in the fetal heart, particularly when considering the risk of associated tuberous sclerosis.

Congenital total lipodystrophy and peripheral pulmonary artery stenosis

Multiple peripheral pulmonary artery stenoses were detected in three patients with congenital generalised lipodystrophy. This association, which has not been described before, may be clinically important in patients with lipodystrophy who present with impaired exercise tolerance or heart murmurs.