Atrial septal defects of secundum type in patients less than 40 years of age. A follow-up study

The series comprised 479 consecutive patients from all parts of Norway operated on in the period 1955-1976. Only 8% were less than 7 years at surgery. Dominating preoperative symptoms were dyspnea and increased fatigue. The follow-up period ranged from 2 to 21 years, mean 10,28 years. There were 4 early deaths (within 30 days after surgery), and at follow-up further 5 patients had died. Excluding a man who died in a traffic accident the total mortality is 1,7%. Of the 470 surviving patients 81,7% were improved, 17% were unchanged and 1,3% had deteriorated. In patients with symptoms dyspnea and palpitations were common complaints. Different types of arrhythmia were found in 31 patients. One third were paroxysmal tachy-arrhythmias, and 9 patients had atrial fibrillation. Only 3 of the 31 patients had some type of preoperative arrhythmia, and 26 were more than 20 years of age of surgery. Seven patients were reoperated because of a residual left to right shunt, 5 of them were initially operated in hypothermia dn inflow occlusion. During the follow-up period 10 patients had late cardiovascular disorders.

Outcome of congenital heart defects--a population-based study

In a population-based study including 35,218 infants born alive during the 15-y period 1982-96, 360 (1%) were diagnosed as having a congenital heart defect (CHD). At a follow-up 3-18 y after birth (median 9.5 y) 154 patients (42.8%) were spontaneously cured; of these, 142 (92.2%) had ventricular septal defects (VSDs). Forty-two patients (11.7%) died, 22 of these (52.4%) during the neonatal period (0-28 d after birth). A total of 119 patients (33.1%) underwent therapeutic procedures (surgery, catheter interventions), 24 (20.2%) of whom died. Of the 95 children surviving therapeutic procedures, 54 (56.8%) had their defects completely repaired, while 41 (43.2%) had residual defects or cardiac sequelae, often of minor importance. In 69 children (19.2%) with persistent non-operated defects, 43 (62.3%) had VSDs. A chromosomal disorder, syndrome or associated extracardiac malformation occurred in 72 children (20%).

CONCLUSIONS

The study underlines the broad variety in severity of CHDs, with a high neonatal mortality rate as well as a high rate of spontaneous cure. It is estimated that 25% of infants born with a CHD will grow into adult age with persistent non-operated defects, residual defects or cardiac sequelae after therapeutic procedures.

Mutational spectrum in the cardioauditory syndrome of Jervell and Lange-Nielsen

Jervell and Lange-Nielsen syndrome (JLNS) is an autosomal recessive syndrome characterised by profound congenital sensorineural deafness and prolongation of the QT interval on the electrocardiogram, representing abnormal ventricular repolarisation. In a study of ten British and Norwegian families with JLNS, we have identified all of the mutations in the KCNQ1 gene, including two that are novel. Of the nine mutations identified in this group of 10 families, five are nonsense or frameshift mutations. Truncation of the protein proximal to the recently identified C-terminal assembly domain is expected to preclude assembly of KCNQ1 monomers into tetramers and explains the recessive inheritance of JLNS. However, study of a frameshift mutation, with a dominant effect phenotypically, suggests the presence of another assembly domain nearer to the N-terminus.

[Catheter closure of open ductus arteriosus--the first 100 patients]

BACKGROUND

Patent ductus arteriosus is increasingly treated with catheter based techniques. We present our results as by the end of 1998 of the first 100 patients given such treatment.

MATERIAL AND METHODS

The 100 patients between 0.6 and 31.4 years were initially treated with one of these devices: The Rashkind umbrella (60 patients), Cook PDA coils (31 patients) or Amplatzer ductal occluders (ten patients). Seven umbrella patients were treated twice, one with an additional umbrella, six with coils; two coil patients twice, one with another coil and one--after embolisation--with a peg.

RESULTS

The overall complete closure rate for all groups was 90% after nine patients had been treated a second time. The primary complete closure rate in pegs was 100%, after reintervention 85% in umbrella and 97% in coil patients. Neither umbrellas nor pegs have embolised. One coil embolised in the course of implantation of 40 coils (2.5%). No other complication has occurred.

INTERPRETATION

The closure of the arterial duct with catheter techniques compares favorably with surgery and is now established as the method of choice. Following the investigational introduction of pegs there is no longer an upper limit in the size of ducts suitable for such treatment.

IsK and KvLQT1: mutation in either of the two subunits of the slow component of the delayed rectifier potassium channel can cause Jervell and Lange-Nielsen syndrome

The Jervell and Lange-Nielsen syndrome (JLNS) comprises profound congenital sensorineural deafness associated with syncopal episodes. These are caused by ventricular arrhythmias secondary to abnormal repolarisation, manifested by a prolonged QT interval on the electrocardiogram. Recently, in families with JLNS, Neyroud et al. reported homozygosity for a single mutation in KVLQT1 , a gene which has previously been shown to be mutated in families with dominantly inherited isolated long QT syndrome [Neyroud et al . (1997) Nature Genet ., 15, 186-189]. We have analysed a group of families with JLNS and shown that the majority are consistent with mutation at this locus: five families of differing ethnic backgrounds were homozygous by descent for markers close to the KVLQT1 gene and a further three families from the same geographical region were shown to be homozygous for a common haplotype and to have the same homozygous mutation of the KVLQT1 gene. However, analysis of a single small consanguineous family excluded linkage to the KVLQT1 gene, establishing genetic heterogeneity in JLNS. The affected children in this family were homozygous by descent for markers on chromosome 21, in a region containing the gene IsK . This codes for a transmembrane protein known to associate with KVLQT1 to form the slow component of the delayed rectifier potassium channel. Sequencing of the affected boys showed a homozygous mutation, demonstrating that mutation in the IsK gene may be a rare cause of JLNS and that an indistinguishable phenotype can arise from mutations in either of the two interacting molecules.

[Hypoplastic left heart syndrome. Present experiences and future possibilities]

The authors report experiences from Norwood's staged palliation for hypoplastic left heart syndrome performed in Philadelphia on Norwegian children. Although there is no universal agreement that these children should be operated at all, the Norwegian health authorities have decided that all expenses for transport, examination and treatment shall be covered by the National Health Insurance Scheme. Since 1987 a total of 21 children have been transported to USA for operation. Eight of these children have completed all the planned stages of the operative treatment. Two are waiting for stage 3. 11 children have died. The authors discuss how to proceed with regard to treatment of this complicated patient group in future.

Pulmonary vascular resistance in complete atrioventricular septal defect. A comparison between children with and without Down's syndrome

Invasive data obtained in children with complete atrioventricular septal defect over the last three years are presented to determine the age at which pulmonary vascular obstructive disease develops. Comparisons were made between children with (n = 21) and without Down's syndrome (n = 12). The investigation was restricted to patients less than one year of age at initial catheterization. Patients with complicated associated heart defects were excluded. Patients with Down's syndrome had a higher ratio of pulmonary to systemic vascular resistance than children without Down's syndrome in the basal situation. This difference almost disappeared after 100% oxygen had been given to patients with elevated pulmonary vascular resistance, indicating that hypoxia and/or hypoventilation is of importance, especially in children with Down's syndrome. Fixed elevated pulmonary vascular resistance was found in 11% of Down patients under one year, with the youngest patient being 5.5 months old. One child without Down's syndrome may have had fixed elevated pulmonary vascular resistance. It is concluded that all children with complete atrioventricular septal defect should be evaluated and operated on at a very young age.

Congenital heart defects, hamartomas of the tongue and polysyndactyly in a sister and brother

We report a sister and brother with congenital heart defects, hamartomas of the tongue and polydactyly. Both had coarctation of the aorta, which was repaired in early infancy. In addition, the girl had atrioventricular canal. She died postoperatively at age 4 years. The boy had subaortic stenosis and died of pneumonia at age 2 years. Both children had normal psychomotor development. The parents were healthy and unrelated. The familial occurrence could be due to a previously unrecognized autosomal recessive syndrome or parental gonadal mosaicism for a dominant syndrome.

[Magnetic tomography in congenital heart defects]

Magnetic resonance imaging (MR) has been shown to be valuable in defining cardiac anatomy in a variety of cardiac abnormalities. The article describes the technique and results of MR in 32 children with congenital heart disease. MR clearly depicts the anatomy of the great vessels, and may be used for the evaluation of palliative systemic-pulmonary artery shunts. In postoperative controls, MR may replace or postpone angio-cardiography. MR is also a promising technique for the evaluation of myocardial and valvular function. Especially in small children, the non-invasive nature of MR is of great importance.

Balloon debanding of the pulmonary artery

Clinical balloon debanding of the pulmonary artery is reported in two patients, 6 months and 4 years of age. The band was made of Dacron, and was closed with one single polypropylene suture. This suture was subsequently ruptured with a balloon inflated within the pulmonary artery at the site of the band. Balloon debanding relieved the gradient almost completely in the two patients. No problems occurred during the procedure. In the future this may prove to be an efficient and reliable way to remove the effect of a pulmonary artery banding.

In vitro balloon dilatation of the banded pulmonary artery

The pulmonary artery of unfixated human heart-lung specimens was banded by placing a Dacron tape around the artery and securing the tape with a 5.0 Prolene suture at selected circumferences. The banding was successfully dilated with a balloon catheter in 24 instances. The mean pressure necessary to burst the suture securing the tape was 2.4 atmospheres.

Metrizamide and metrizoate for cardioangiography in infants and children

Metrizamide was compared with metrizoate in a double blind investigation. Cardioangiography was performed in 30 infants and children below 2 years of age with congenital heart disease. Adverse reactions were few and unimportant. Changes in ECG, ventricular pressure and heart rate during and after the contrast injections were recorded. The side effects were slight in both groups. Metrizamide caused less changes than metrizoate at a statistically significant level.

Tricuspid atresia corrected with valved xenograft conduits

In eight patients from 1976 until 1980, tricuspid atresia (TA) was corrected with valved xenograft conduits between either the right atrium and the main pulmonary artery or between the right atrium and the rudimentary right ventricle. All patients suffered from transient right-heart failure postoperatively and eventually developed normalized cardiac function throughout the first two months after operation. At recatheterization one year postoperatively, the right atrial pressure had generally only increased slightly, the pulmonary artery pressure was normal in all patients and only minor pressure differences were present across the valved conduits. X-ray examination showed normalization of the heart size in the majority of the patients, and in those with conduits between the right atrium and the right ventricle a considerable enlargement of the right ventricular chamber together with normalization of right ventricular contractility had developed. Arterial oxygen saturation, haemoglobin and haematocrit valves had normalized in all patients. One patient died postoperatively of intractable right ventricular failure, septicaemia and intravascular coagulation, and another was uneventfully re-operated on two years postoperatively because of conduit thrombosis. Clinical results were gratifying. Two patients with valved conduits between the right atrium and the right ventricle showed a normal unrestricted level of activity without medication, while patients with valved conduits between the right atrium and the main pulmonary artery were digitalized with an almost normal level of activity. Early repair with valved conduits of patients with TA is advocated.

Coarctation of the aorta. A follow-up study after surgical treatment in infancy and childhood

Between 1951 and 1973, 138 patients aged 0 to 12 years were operated on for coarctation of the aorta. Ten of 18 infants died early. There were 3 late deaths, 2 occurred suddenly and 1 after reoperation. Three of the 125 late survivors had severe, 19 had slight symptoms, while 103 had no complaints, 3 of whom refused examination. The remaining 122 cases were examined between 2 and 24 years (mean 10.9 years) after the operation. Two patients had sequelae from an operative spinal cord injury and 2 had late hemipareses (traumatic in one). Recoarctation, defined as arm/leg pressure gradient exceeding mmHg, totally occurred in 18.7%, and in 4 of 7 cases operated on in infancy. Hypertension without recoarctation was observed in 17.2% and associated cardiovascular anomalies in 18% of the late survivors. It is suggested that the optimal age for surgical repair of coarctation of the aorta is between 4 and 6 years of age. A long-term follow-up is recommended in all patients.