Transcatheter closure of secundum atrial septal defects with the amplatzer septal occluder: early experience.

BACKGROUND: Secundum atrial septal defect is a common congenital heart defect that causes right heart volume overload and produces symptoms usually after the third decade of life. Treatment until the last few years has been open heart surgery. OBJECTIVES: To review our early experience with transcatheter closure of ASD2 using the Amplatzer septal occluder. METHODS: Between November 1999 and February 2000, 20 children and young adults with a median age of 9.1 years (4.2-35.1 years) were referred for transcatheter closure of ASD2. Diagnosis was established by transthoracic echocardiography. Implantation was performed under general anesthesia through the femoral vein with the guidance of transesophageal echocardiography and fluoroscopy. Femoral arterial puncture was performed for blood pressure monitoring during the procedure. The device size chosen was similar to the balloon-stretched diameter of the ASD2. RESULTS: Implantation was completed successfully in 18 patients. Two patients were referred for elective surgery: one had an unsuitable anatomy for transcatheter closure by TEE in the catheterization laboratory and the device could not be implanted properly, the other patient had a large multiperforated septal aneurysm that was retrieved. Mean ASD2 diameter by TTE and TEE was similar (13.9 +/- 3 mm, 13.4 +/- 3.5 mm) and mean stretched diameter was 18.3 +/- 4.3 mm. Mean Qp:Qs (pulmonary flow:systemic flow) was 2.2 +/- 0.6. Mean fluoroscopy time for the procedure was 14.8 +/- 4.8 minutes. The patients were discharged the day after the procedure. Four patients had a tiny leak immediately post-procedure, and none had a leak at one month follow-up. The only complication was a small pseudoaneurysm of the femoral artery in one patient, that resolved spontaneously. CONCLUSIONS: Transcatheter closure of ASD2 with the Amplatzer septal occluder is a safe and effective alternative to surgical closure. Long-term outcome has to be evaluated.

Anomalous origin of the left coronary artery from the pulmonary artery: diagnosis and postoperative follow up.

BACKGROUND: Anomalous origin of the left coronary artery from the pulmonary artery is a rare congenital malformation that presents a diagnostic challenge to the pediatrician and pediatric cardiologist. Although surgical repair is always indicated, the optimal technique has yet to be determined. OBJECTIVES: To review our experience with the diagnosis of children with ALCAPA and to assess short to midterm surgical results. METHODS: Between 1992 and 1998, 13 infants and children (2 months to 15 years) were treated for ALCAPA at our medical center. Eight were diagnosed during the first year of life; all were symptomatic and had severe dysfunction of the left ventricle. The five patients diagnosed at an older age had normal myocardial function. Diagnosis was established by echocardiography alone in seven patients; six required catheterization (one infant and all older patients). Surgery was performed in 12 patients to establish dual coronary artery system: 7 underwent the Takeuchi procedure and 5 had re-implantation of the anomalous left coronary artery. RESULTS: One infant died shortly after diagnosis before surgical repair was attempted, and one died postoperatively. Four patients required additional surgery: three for late complications of the Takeuchi procedure and one valve replacement for mitral insufficiency. Recent evaluation revealed good global left ventricle function in all patients except for one, who is still within the recovery phase and shows gradual improvement. However, most patients who presented with severe myocardial dysfunction upon diagnosis still display abnormal features such as echo-dense papillary muscles or evidence of small akinetic segments. In this group, early repair was associated with faster myocardial recovery. CONCLUSIONS: The diagnosis of ALCAPA remains a clinical challenge to the pediatrician and cardiologist. Diagnosis can be established echocardiographically, and early diagnosis and treatment may lead to faster myocardial recovery. The preferred surgical method appears to be re-implantation of the ALCA. The chance for good recovery of global ventricular function is high even in the sickest patients, nonetheless abnormal myocardial features can be identified even years after surgery.

The Ross operation: initial Israeli experience.

BACKGROUND: The need for aortic valve replacement in children and young adults poses a special problem to cardiologists and surgeons. Replacing the sick aortic valve with the patient's pulmonary valve as described by Ross has proven to be a good option in this special age group. OBJECTIVE: To review our initial experience in order to assess the short-term results. METHODS: From January 1996 to June 1999, 40 patients (age 8 months to 41 years) underwent aortic valve replacement with pulmonary autograft. Indications for surgery were congenital aortic valve disease in 30 patients, bacterial endocarditis in 5, rheumatic fever in 3, and complex left ventricular outflow tract obstruction in 3. Trans-esophageal echocardiography was performed preoperatively and post-bypass in all patients, and transthoracic echocardiography was done prior to discharge and on follow-up. RESULTS: There was no preoperative or late mortality. All patients remain in functional class I (New York Heart Association) and are free of complications and medication. None showed progression of autograft insufficiency or LVOT obstruction. Homograft insufficiency in the pulmonary position has progressed from mild to moderate in one patient, and three developed mild homograft stenosis. CONCLUSIONS: The Ross procedure can be performed with good results in the young population and is considered an elegant surgical alternative to prosthetic values and homografts.

Acute complications in the current era of therapeutic cardiac catheterization for congenital heart disease.

The acute complications of therapeutic cardiac catheterization for congenital heart disease as performed currently in a small unit were reviewed. In recent years, there has been a significant increase in the number of lesions thought amenable to catheter therapy. Only a few reports, however, have addressed the overall incidence of acute complications of therapeutic cardiac catheterization, all representing the experience of centres performing moderate-to-large numbers of procedures. A retrospective review was performed of 425 therapeutic catheter procedures performed at our institution between May 1993 and November 1997. Acute complications were retrieved from the database. This included all adverse events that were clinically recognized at the time of or within 2 weeks after the procedure and which, to the best of the authors' clinical judgement, were related to the catheterization and not part of the natural history of the child's illness. All patients were observed overnight following the procedure, and stayed in hospital if a complication developed. There were 49 acute complications (11.5%), of which 43 (10.1%) were deemed minor and 6 (1.4%) were considered major. The rate was low in patients with valvar pulmonary stenosis, including three neonates (3/45, 6.7%), for those undergoing angioplasty of native co-arctation (1/15, 6.7%) and pulmonary arteries (2/27, 7.4%); and for coil embolization of systemic to pulmonary collateral arteries (1/16, 6.3%). The rate was high in patients with valvar aortic stenosis, including 12 neonates (9/37, 24.3%), and for angioplasty of re-coarctation (4/23, 21.7%). There were more overall complications in neonates (25.6%) than in older patients (10.1%) (p < 0.01). Two patients died (0.5%), but no patient required emergency surgical intervention. In spite of the introduction of many new therapeutic modalities with greater intrinsic risk, and the fact that patients with more complex lesions and who are more acutely ill are being treated, the overall rate of complications remains relatively low. This probably reflects improvements in pericatheterization medical management, in selection of patients, in procedural techniques, and in the experience of operators.

Interventional catheterization decreases plasma levels of atrial natriuretic peptide (ANP) in children with congenital heart defects.

Atrial natriuretic peptide (ANP) is one of the cardiac peptides implicated in volume and sodium homeostasis. We investigated the effect of interventional catheterization on plasma levels of ANP, aldosterone, and cortisol in 28 children with various congenital heart defects (CHD). Patients were divided by age into two groups: group A--infants and children over 3 months of age (n = 22), and group B--newborns (n = 6). These were compared to age-matched control groups. In group A, interventions included pulmonic valvotomy (n = 8), aortic valvotomy (n = 4), balloon angioplasty of native coarctation of the aorta (n = 3), balloon dilatation of the mitral valve (n = 1), and Rashkind double umbrella closure of patent ductus arteriosus (n = 6). Group B interventions included pulmonic valvotomy (n = 3), aortic valvotomy (n = 1), and balloon atrial septosomy (n = 2). In group A, mean ANP levels were markedly higher than in age-matched controls (125.2+/-15.8 vs. 24.6+/-4.6 pg/ml) (P <0.0001), and decreased immediately after intervention (75.6+/-11.4 pg/ml, P <0.02), and more markedly on follow-up (42.9+/-5.0 pg/ml, P < 0.0001). In group B (newborns), mean basal plasma levels were high before and after intervention and were not different from age-matched controls (243+/-42.1 vs. 220.8+/-16.2 pg/ml). There was a significant decrease on follow-up measurement (62.1+/-12.7 pg/ml, P < 0.005). In both groups, plasma cortisol levels increased significantly immediately following catheterization (P < 0.02), and normalized on follow-up. Basal aldosterone levels were normal in group A and high in Group B (9.9+/-3.8 vs. 167.6+/-16.9 ng/dl) (P < 0.001). It is suggested that plasma ANP levels are increased in children with CHD, without overt heart failure, and decrease significantly following successful intervention. In newborns with CHD, the physiological high ANP levels obscure the effect of the CHD.

Midterm clinical impact versus procedural success of balloon angioplasty for pulmonary artery stenosis.

The objective of this study was to determine the procedural success rate of balloon angioplasty for branch pulmonary artery stenosis in terms of its clinical impact on the subsequent management of these patients. Most previous studies of balloon angioplasty have concentrated on the initial success rate (50-60%), complications (6-10%), recurrence rate ( approximately 15%), and technical issues. A favorable clinical impact was noted in only 35% of patients. Over a 3-year period (March 1990 to March 1993), 32 patients (17 boys, 15 girls) underwent 34 balloon angioplasty procedures. Their mean age at dilation was 7.6 +/- 4.3 years (range 1.1-19.0 years). Postoperative tetralogy of Fallot and tetralogy of Fallot with pulmonary atresia were the most frequent cardiac lesions (44%). The procedures were "technically" successful in 56% (19 of 34) of balloon dilations on the basis of at least two of the following criteria: an increase of >50% of the predilation diameter; an increase of >20% in the relative flow to the affected lung by radioisotope study; or a decrease in the systolic right ventricular/aortic pressure ratio from 85-100% to <60%. Twelve percent of the patients had transient complications (two deep vein thromboses, one unilateral pulmonary edema, and one pneumothorax). In 17 of 19 (89%) of the patients there was a favorable clinical impact on their subsequent care as based on one of the following criteria: resolution of the stenosis and avoidance of surgical intervention (n = 14); optimization of future surgical procedure (n = 3); reduction in right ventricular pressure to <60% of aortic pressure (n = 13). Five patients who had unsuccessful balloon angioplasty and one with initially successful balloon angioplasty later underwent endovascular stent placement, which also favorably influenced their clinical status. The success rate of balloon angioplasty for branch pulmonary artery stenosis, when measured by strict procedural criteria, is accompanied by a favorable clinical impact in more than 50% of patients. Hence this procedure should be the initial therapeutic modality in this setting despite the relatively high transient complication rate. The use of endovascular stents probably increases the favorable clinical impact.

Radiofrequency catheter ablation of ectopic atrial tachycardia.

Ectopic atrial tachycardia (EAT) is an uncommon type of supraventricular tachycardia. It is usually chronic, incessant and resistant to pharmacologic therapy. Radiofrequency catheter ablation, which has become one of the treatments of choice for the more common types of supraventricular tachycardia, has recently also been shown to be effective in EAT. Radiofrequency catheter ablation was attempted in three patients with incessant EAT. Two of the patients, aged 7 and 13 years, had signs of left ventricular dysfunction, and the EAT originated in the left atrium. The remaining patient, aged 72 years, had a right EAT with normal left ventricular function. Radiofrequency ablation was guided by endocardial atrial mapping to locate the site of earliest atrial activation. Ablation was successful in all three patients, with complete cure of the tachycardia for a follow-up period of 12 to 19 months. Radiofrequency catheter ablation of EAT is highly successful and should be considered as one of the treatments of choice for this arrhythmia.

Non-traditional risk factors for atherosclerosis in high risk children.

Non-traditional risk factors for atherosclerosis were examined in children whose fathers suffered from myocardial infarction up to age 48. Factors examined were hyperinsulinemia, insulin resistance, lipoprotein(a) [Lp(a)], fibrinogen, cardiovascular hyperreactivity, and autonomic nervous system dysfunction. Hyperinsulinemia was present in five cases (9%) and hypoinsulinemia in two. Insulin output following glucose load was significantly higher in obese children compared with controls. There was an increase in Lp(a) alone in 14 cases (24%) and with low density lipoprotein in 6 cases. Increased fibrinogen and positive correlation with insulin abnormality was present in 29% (76% females) (P >0.02). Cardiac hyperreactivity (increased systolic blood pressure) was present in 9% and increased blood pressure and pulse rate in 17%. Holter monitoring pattern was sympathetic in 39% and parasympathetic in 47% of cases. Thus a number of non-traditional risk factors were found to be higher than normal in a relatively large number of children at high risk for atherosclerosis, with 25 children having more than three risk factors.

Late death from aneurysm rupture following balloon angioplasty for branch pulmonary artery stenosis.

We report on a child with Williams syndrome who died from aneurysm rupture 2 weeks following balloon angioplasty for branch pulmonary artery stenosis.

Percutaneous closure of small patent ductus arteriosus: comparison of Rashkind double-umbrella device and occluding spring coils.

We compared our current practice of closing small patent ductus arteriosus (PDA) with coils with our previous experience of using double-umbrellas. Twelve patients underwent percutaneous closure of a small PDA with a coil. Selection criteria were a minimal diameter of < or = 2.5 mm and angiographic type A or E. The 12 most recent, non-consecutive patients who had undergone double-umbrella device closure of a PDA and would presently be considered suitable candidates for spring coil occlusion were retrospectively reviewed. The two groups were compared with regard to complications and immediate and midterm results. Eleven of the 12 attempted PDA occlusions using spring coils were successful. The mean follow-up period was 5.8 +/- 4.6 months. Color-Doppler echocardiograms have shown no residual leaks, no turbulence in the descending aorta, and no left pulmonary artery stenosis. All 12 attempted double-umbrella device placements were successful. The mean follow-up period was 16.2 +/- 5.8 months. Color-Doppler echocardiograms have shown trivial residual leaks in four patients and mild turbulent flow in the left pulmonary artery in one patient. There was no significant difference between the two groups in demographic and hemodynamic data. Although the mean follow-up time was significantly longer in the patients who underwent double-umbrella closure, there was significantly more color-Doppler echocardiographic evidence of residual flow (P < 0.03). Small PDA closure with coils is effective, resulting in less residual leaks compared with the double-umbrella device.

Balloon dilation of pulmonary venous pathway obstruction in an infant after the mustard procedure.

Pulmonary venous pathway obstruction developed after a Mustard procedure in an infant with transposition of the great arteries. The stenosis was successfully dilated by the percutaneous balloon technique with immediate clinical, echocardiographic, and hemodynamic improvement, which has persisted for 8 months after dilation. This technique is a feasible alternative to reoperation in such an obstruction, even in infants.

Lung perfusion scans in patients with congenital heart defects.

In 63 patients with various congenital heart defects, lung perfusion was evaluated with technetium-99mm macroaggregated albumin. Right lung perfusion abnormalities were documented in 34 patients (54%). A particularly high incidence occurred in patients who had undergone a systemic to pulmonary artery shunt operation as an initial palliative procedure or who had had right ventricular outflow reconstruction and in those with bilateral pulmonary artery stenosis. Serial studies were helpful in evaluating the functional results of different transcatheter interventions for optimizing pulmonary blood flow. The quantitative relative perfusion radionuclide method was a more sensitive means of detecting cases of abnormal lung perfusion than was chest radiology.

Hypothermia and exsanguination in emergency cardiovascular surgery in children.

Emergency cardiac surgery in children can be successfully carried out even when cardiopulmonary bypass is either not feasible or not available quickly enough. Hypothermia induced with ice-water bags, complete circulatory arrest, near-total body exsanguination, and rewarming with a heating blanket and heating lamps, were used twice successfully in the repair of a ruptured aneurysm of the ascending aorta.

The use of carbon dioxide fiberoptic laser catheter for atrial septostomy.

The development of optical fibers capable of transmitting laser energy has encouraged the experimental use of laser irradiation for the treatment of acquired cardiovascular disorders. One of the key questions is which combination of laser source, energy parameters, and transmitting fiberoptic would be best suited for intravascular use. In most experiments argon, neodymium-YAG, and excimer lasers, coupled to suitable optical fibers, have been used. We now describe the use of a carbon dioxide fiberoptic laser catheter for the creation of an atrial septal defect. Silver halide infrared transmitting fibers were inserted into standard 6 French cardiovascular catheters. This laser catheter system, capable of transmitting several watts of pulsed CO2 laser energy, was initially used to create atrial septal defects in isolated dog hearts to determine the best energy parameters. Atrial septostomy was later performed successfully in four of five anesthetized dogs. The thermal damage extended 50 to 60 micron beyond the "holes" created by the laser irradiation in the interatrial septum. Thus, pulsed CO2 laser irradiation, delivered through optical fibers, can create an atrial septal defect.

Bidirectional flow in congenital ventricular septal defect: a Doppler echocardiographic study.

The purpose of this study was to demonstrate the value of combined two-dimensional and pulsed Doppler echocardiography (echo) in localizing and recording bidirectional flow in congenital ventricular septal defect. Eight children, aged 8 months to 16 years, with clinical signs of a ventricular septal defect, underwent two-dimensional and pulsed Doppler echo study prior to cardiac catheterization. The ventricular septal defect was documented anatomically by two-dimensional echo in all eight patients. Flow patterns in systole and diastole through the ventricular septal defect and on both sides of the defect were carefully studied. In all eight children, systolic, high velocity, pathologic, left to right flow was documented when the sampling volume was positioned on the right ventricular side of the defect. When the sampling volume was positioned inside the defect, to and fro flow, left to right in systole and right to left in diastole, was observed. In children with moderate to large defects, the diastolic flow had a peak in early diastole. Increased pressure in the right ventricle over the left ventricle during the same period was demonstrated by cardiac catheterization and coincided with the Doppler flow. The direction of flow across the defect was affected by the size of the defect and the magnitude of the net shunt. Two-dimensional and pulsed echo Doppler were shown to be useful in demonstrating the ventricular septal defect and estimating its size and hemodynamic significance noninvasively.

Ectopic origin of a coronary artery from the aorta. Sudden death in 3 of 23 patients.

Ectopic origin of a coronary artery from the aorta is uncommon. In the last decade, its importance as a possible cause of sudden death has been documented. Initially, only the left coronary artery was implicated. Lately, the ectopically arising right coronary artery has also been shown to be involved in cases of sudden death. We reviewed the pathologic anatomy in 23 cases of ectopic origin of a coronary artery from the aorta. In three of these cases, death could be attributed to ectopic origin of a coronary artery. In one case the left coronary artery arose from the right aortic sinus, and in two cases the right coronary artery arose from the left aortic sinus. In one of these, a scar of healed myocardial infarction was present in the inferior wall of the left ventricle. The possible mechanism for sudden death in these cases is reviewed and emphasis placed on the theory that the acute angle at which the ectopic artery leaves the aorta results in a flap-like mechanism at the arterial ostium. Ostial stenosis by the flap could be a significant factor in causing myocardial ischemia in some patients and also in sudden death.

Prosthetic valve replacement in infants and children.

A review of 41 children from 10 months to 16 years of age who had a valve replacement between the years 1966 to 1981 is reported. Sixty-one per cent of the valve deformities were rheumatic and 39% congenital. Twenty-two children had the mitral valve replaced, 14 had an aortic valve and 5 had both aortic and mitral valve replacement. There was a hospital mortality of 9.7% and only one later death during a mean follow up period of 6.75 years. Three children have required a second mitral valve replacement. Thrombo-embolic episodes were encountered in 4 children. The special problems of valve replacement in infants and children are discussed.