Modified technique for balloon valvuloplasty of critical pulmonary stenosis in the newborn.

OBJECTIVES: We report our experience in eight consecutive neonates who underwent attempted balloon dilation as an initial therapy for critical valvular pulmonary stenosis, and we review in detail technical modifications that improved the success rate. BACKGROUND: Balloon dilation of the pulmonary valve has become the treatment of choice for valvular pulmonary stenosis in children and adults. There are few reports of its effectiveness in critical pulmonary stenosis in the newborn. In this setting, application of the technique of balloon dilation has been limited by the ability to advance the necessary guide wires and catheters across the stenotic, often near-atretic, pulmonary valve. METHODS: The pulmonary valve was crossed in all patients. When this could not be accomplished with an end-hole catheter, a soft guide wire was advanced directly across the pulmonary valve through the end-hole catheter positioned in the right ventricular outflow tract below the valve. Initial predilation was achieved in all patients by using a coronary dilation catheter in an effort to facilitate introduction of the definitive balloon dilation catheter. Definitive dilation with a balloon diameter of > or = 110% of the diameter of the pulmonary valve annulus was possible in six patients. RESULTS: Right ventricular pressure declined from a mean value of 108 +/- 32 mm Hg to a mean value of 49 +/- 11 mm Hg after balloon dilation, with no change in heart rate or aortic pressure in these six patients after definitive balloon dilation. CONCLUSIONS: The results of this small series suggest that critical valvular pulmonary stenosis in the newborn can be successfully treated by transluminal balloon valvuloplasty.

Ventricular arrhythmias and biventricular dysfunction after repair of tetralogy of Fallot.

To test the hypothesis that subclinical levels of ventricular dysfunction contribute to the development of ventricular arrhythmias after repair of tetralogy of Fallot, 38 postoperative patients were studied by radionuclide ventriculography and M-mode echocardiography. Eighteen patients (group I) had Lown grade 2 or greater ventricular arrhythmias on ambulatory electrocardiography or treadmill exercise, or both; 20 patients (group II) had no documented ventricular arrhythmias. Radionuclide ventriculograms were performed using technetium -99m-labeled red cells; ejection fractions were derived by computer from multigated images, with normal values being 45% for the right ventricle and 55% for the left ventricle. From M-mode echocardiography, right and left ventricular end-diastolic dimensions were expressed as a ratio, the highest normal value being 0.45. By radionuclide ventriculography, right ventricular ejection fraction was lower for group I (28 +/- 3%) than for group II (31 +/- 2%), but the difference was not significant (p less than 0.10). Left ventricular ejection fraction was significantly lower for group I than for group II (45 +/- 5% versus 55 +/- 3%, p less than 0.05). The echocardiographic right and left ventricular diastolic dimension ratio was elevated in all patients except two in group II; it was significantly greater in group I than in group II (0.84 +/- 0.06 versus 0.63 +/- 0.04, p less than 0.005). This study provides evidence for right ventricular dilation by M-mode echocardiography and for biventricular dysfunction by radionuclide ventriculography in patients who have undergone repair of tetralogy of Fallot.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac tumors and the nevoid basal cell carcinoma syndrome.

Nevoid basal cell carcinoma syndrome is a multisystem disease with a wide range of initial symptoms that can be seen at any age. The most characteristic features are vertebral or rib anomalies, intracranial falx calcification, multiple basal cell carcinomas, odontogenic keratocysts of the jaw, and palmar and/or plantar pits. Pediatricians need to be aware that if any one of these major anomalies is seen, this diagnosis should be considered. There now appears to be an established association between cardiac tumors and nevoid basal cell carcinoma syndrome. Primary cardiac tumors have been associated with cerebral tuberous sclerosis and neurofibromatosis, and evaluation of cardiac status is recommended when these genetically determined syndromes are diagnosed. This communication should serve to alert pediatricians to the need for complete cardiac evaluation and genetic counseling when a diagnosis of nevoid basal cell carcinoma is made.

Atenolol therapy for exercise-induced hypertension after aortic coarctation repair.

After successful repair of coarctation of the aorta in childhood, exercise-induced upper body systolic hypertension is well documented. Beta blockade has been shown to reduce the arm/leg gradient in untreated coarctation of the aorta; treatment before coarctation repair has decreased paradoxical hypertension after repair. Ten patients with successful surgical repair of coarctation, defined as a resting arm/leg gradient of less than or equal to 18 mm Hg, were evaluated by treadmill exercise before and after beta blockade with atenolol. Mean age was 5.5 years at repair and 18 at study. At baseline evaluation, systolic blood pressures at termination of exercise ranged from 201 to 270 mm Hg (mean 229 mm Hg). Arm/leg gradients at exercise termination ranged from 30 to 143 mm Hg (mean 84). Follow-up treadmill exercise studies were performed after beta blockade. Upper extremity systolic pressures at exercise termination were normalized in 9 of 10 patients. Maximal systolic blood pressure recorded at exercise termination ranged from 163 to 223 mm Hg (mean 196 mm Hg, p less than or equal to 0.005). Arm/leg gradient at termination of exercise also decreased significantly to a mean of 51 mm Hg (p less than 0.05). No patient had symptoms on atenolol and exercise endurance times were unchanged. The study results in this small series suggest that cardioselective beta blockade can be used to treat exercise-induced upper body hypertension effectively after surgical repair of coarctation. Because a high incidence of premature cardiovascular disease has been well documented after satisfactory surgical repair, the findings are of importance for this group of postoperative patients.

Sinus node shift after the Senning procedure compared with the Mustard procedure for transposition of the great arteries.

To investigate the nature of the dominant intrinsic cardiac pacemaker activity after the Senning procedure, endocardial mapping of the systemic venous atrium was accomplished a mean of 13 months after operation in 10 patients, aged 22 +/- 6 months. Multiple endocardial sites were measured to find the earliest atrial electrical activity timed back from the QRS complex. These data were compared with data from endocardial mapping performed in 6 patients late after the Mustard procedure. In 8 of 10 patients who had undergone the Senning procedure, the earliest activation time, corresponding by definition to the origin of the intrinsic pacemaker, was located in the inferior medial portion of the superior limb of the systemic venous atrium. In the other 2 patients who had undergone the Senning procedure, the earliest activity was in the high superior limb of the baffle at its junction with the superior vena cava. In contrast, the earliest activity in all patients who underwent the Mustard operation was at the junction of the superior vena cava and the superior limb of the systemic venous atrium. In response to programmed extrastimulation, the electrophysiologic behavior of the intrinsic pacemaker in the Senning group was abnormal compared with known normal sinus node (SN) data in only 3 of 10 patients, whereas all patients in the Mustard group had SN dysfunction. Abnormal SN function was noted in both patients in the Senning group, in whom a shift in the position of the earliest endocardial activation point was not seen.(ABSTRACT TRUNCATED AT 250 WORDS)

Hemodynamic and electrophysiologic results of the Senning procedure for transposition of the great arteries.

Of 24 patients, aged 6 days to 24 months, undergoing the Senning procedure for transposition of the great arteries, 2 patients died perioperatively (8% operative mortality): 1 patient, a neonate, from sepsis and 1 patient, born prematurely and with multiple anomalies, from congestive heart failure. One patient died late postoperatively from noncardiac causes. The 21 survivors are clinically well, and in 20 complete hemodynamic and electrophysiologic data were obtained by cardiac catheterization a mean of 13 months after repair. All patients have normal systemic arterial oxygen saturation. Left ventricular function and pulmonary artery pressures are normal in all. None had pulmonary venous obstruction. Narrowing at the junction of the superior vena cava and systemic venous atrium with mean pressure differences of 5 mm Hg or more was found in 4 of the 20 patients, but was clinically manifest in only 1 patient. No abnormality of atrioventricular conduction was seen in response to programmed electrical stimulation. Sinus node dysfunction was present in 6 patients, with abnormalities of both automaticity and sinoatrial conduction. Among these 6 patients were the 5 who were younger than 5 months at operation. The Senning procedure generally results in excellent hemodynamic and electrophysiologic status in patients who undergo operation after the newborn period. Identification of sinus node dysfunction, seen in patients in whom the procedure is performed in the first few months of life, is of concern and identifies a need for close follow-up of sinus node function in this cohort of patients.

The changing pattern of infective endocarditis in childhood.

Forty-eight cases of infective endocarditis (IE) that occurred in 42 patients with congenital heart disease were reviewed from 1970 through 1990 and were compared with a 20-year review of 108 cases diagnosed between 1953 and 1972. The review demonstrates that the natural history of IE in children has changed over the last 2 decades, with half of the cases occurring after surgery for congenital heart disease. In the postoperative group, 46% of patients had undergone valve replacement and 7 of these (29%) had a right ventricular to pulmonary artery valved conduit as the site for IE, suggesting significant additional risk in this setting. Among patients with nonsurgically treated congenital heart disease and IE, mitral valve prolapse has emerged as an important underlying heart lesion occurring in 29% of patients. The bacterial spectrum has shifted, with a significant increase in the incidence of uncommon causative organisms. Mortality has continued to decline with survivorship of 90% in this series.

Postoperative functional assessment of a modified surgical approach to repair of tetralogy of Fallot.

Since February 1982, we have used a modified technique to repair tetralogy of Fallot with transatrial closure of the ventricular septal defect, a short infundibular incision with avoidance of muscle resection, and anterior expansion of the right ventricular outflow tract using a patch in every case. The pulmonary anulus is approached in the usual manner. Twenty-six patients have had repair with this technique without mortality, and 20 patients (Group 1) have been evaluated 1 to 3 years postoperatively. Their results are compared with those of all patients followed up in our division who had had repair by the traditional technique in the 5 years before February 1982, with the same evaluation within 4 years of operation (Group 2, n = 22). Ten of 20 patients in Group 1 and 14 of 22 in Group 2 required a transannular patch. At cardiac catheterization, right ventricular outflow tract obstruction was effectively relieved in both groups (right ventricular systolic pressure [mean +/- standard error], Group 1 versus Group 2, 45 +/- 5 versus 49 +/- 4 mm Hg). No patient with the modified technique had a residual ventricular septal defect. By M-mode echocardiography, right ventricular-left ventricular end-diastolic dimension ratio was significantly lower for Group 1 patients (0.58 +/- 0.03 versus 0.78 +/- 0.04; normal less than 0.45; p less than 0.001). With radionuclide ventriculography, right ventricular ejection fractions were significantly higher for Group 1 patients with the modified repair (38% +/- 2.2% versus 33% +/- 1.8%; normal greater than or equal to 45%; p less than 0.05). Because the incidence of obligatory pulmonary insufficiency caused by transannular patch is similar in both groups, these results cannot be directly attributed to the presence of pulmonary insufficiency alone. With ambulatory electrocardiographic monitoring, no patient in Group 1 had any ventricular premature contractions whatsoever, whereas six of 22 patients in Group 2 had demonstrable ventricular premature contractions. These results suggest that in children with tetralogy of Fallot, right ventricular outflow tract obstruction can be effectively relieved with this modified approach with improved early preservation of right ventricular function.

Severe feeding difficulty in infants with increased pulmonary blood flow.

Three infants with significant left-to-right intracardiac shunts and moderate cardiac disability failed to thrive primarily because of a complete distaste for food. They refused to feed, spat out food introduced into their mouths, and vomited food that reached their stomachs. These severe feeding difficulties were relieved by intracardiac repair, and we conclude that in some unusual instances such feeding disorders constitute the indication for operation.

Improved right ventricular function following late pulmonary valve replacement for residual pulmonary insufficiency or stenosis.

Residual severe pulmonary insufficiency or stenosis may result in significant myocardial dysfunction late after repair of tetralogy of Fallot. Although pulmonary valve replacement has been advocated for selected patients, objective improvement in right ventricular function has been difficult to demonstrate. We undertook pulmonary valve replacement in 11 patients to treat residual insufficiency (n = 8) or stenosis (n = 3) and evaluated them before and after operation by radionuclide ventriculography and M-mode echocardiography. Patients' age at the original repair was 6.6 +/- 0.6 years (range 2 to 8 years) and at subsequent valve replacement was 14.6 +/- 1.5 years (range 5 to 20 years). Indications for pulmonary valve replacement were conduit stenosis indicated by a gradient greater than or equal to 75 mm Hg (n = 3), symptoms (n = 2), progressive cardiomegaly (n = 3), and new onset of tricuspid insufficiency (n = 3). Prior to pulmonary valve replacement, right ventricular ejection fraction was 0.29 +/- 0.12 (range 0.12 to 0.48) and rose to 0.35 +/- 0.10 (range 0.19 to 0.48) at a mean of 10.5 +/- 2.3 months after operation (p less than 0.05). Improvement (defined as an increase in ejection fraction greater than 0.05) was noted in seven patients whereas four demonstrated no change. Left ventricular ejection fraction before operation (0.55 +/- 0.12) was unchanged after pulmonary valve replacement (0.54 +/- 0.06). M-mode echocardiography demonstrated significant reduction in right ventricular dilatation. Right ventricular/left ventricular end-diastolic dimension fell from 1.03 +/- 0.30 to 0.73 +/- 0.13 after operation (p less than 0.01). Cardiothoracic ratio fell from 0.59 +/- 0.02 to 0.55 +/- 0.02 at a mean of 12 months after pulmonary valve replacement (p less than 0.01). Subjective improvement in exercise tolerance was noted in all seven patients who showed an increase in right ventricular ejection fraction. Of the remaining four patients, two had no improvement, one felt symptomatically improved, and one was too young for evaluation. These data demonstrate objective improvement in right ventricular function following pulmonary valve replacement and confirm the usefulness of this procedure in patients with significant right ventricular dysfunction secondary to residual pulmonary insufficiency and stenosis.

The influence of pulmonary insufficiency on ventricular function following repair of tetralogy of Fallot. Evaluation using radionuclide ventriculography.

Long-standing pulmonary insufficiency after repair of tetralogy of Fallot may adversely affect ventricular function. We evaluated 20 patients at a mean of 9 years after repair by radionuclide ventriculography, 24 hour Holter monitoring, and M-mode echocardiography. The mean age at complete repair was 7.1 +/- 2.6 years. Patients were divided into groups as follows: Group I (eight patients), no clinical pulmonary insufficiency; Group II (12 patients), moderate to severe pulmonary insufficiency. Group II was further divided: Group IIa, transannular patch (six patients); Group IIb, no transannular patch (six patients). There was no difference between groups for age at operation, duration of follow-up, right ventricular pressure, or right ventricular-pulmonary arterial gradient. No patient had a residual shunt and all were in New York Heart Association Class I. Serious ventricular dysrhythmias occurred in 38% of Group I patients and 50% of Group II (p = NS). The echocardiographic ratio of right to left ventricular end-diastolic dimension was greater in patients with pulmonary insufficiency than in those without pulmonary insufficiency: 0.83 +/- 0.17 versus 0.55 +/- 0.15, p less than 0.01. Right ventricular ejection fraction was 0.39 +/- 0.08 in Group I and 0.27 +/- 0.07 in Group II, p less than 0.01. Left ventricular ejection fraction was 0.64 +/- 0.12 in Group I and 0.53 +/- 0.07 in Group II, p less than 0.02. Radionuclide angiography is a useful means of identifying right ventricular dysfunction following repair of tetralogy of Fallot. The dysfunction appears significantly worse in patients with pulmonary insufficiency.

Results with the two-patch technique for repair of complete atrioventricular septal defect.

From May, 1982, to September, 1983, 9 patients underwent repair of complete AV septal defect. They ranged in age from 11 months to 48 months and in weight from 5.3 kg to 16.5 kg. Seven patients were 24 months old or less. Previous operations included pulmonary artery banding in 1 patient and ligation of a patent ductus arteriosus with repair of coarctation in another. All patients had large left-to-right shunts (mean pulmonary to systemic flow ratio, 3.1), and the 7 young infants had marked pulmonary hypertension. Mitral regurgitation was absent in 2 patients, mild in 3, moderate in 2, and severe in 2. One patient had the right ventricular dominant form of complete AV septal defect. In all instances, repair was done using separate ventricular and atrial patches. Leaflet tissue was not divided, and a trileaflet mitral valve was left in each patient. Eight patients survived operation and are well 3 to 17 months after repair. The single operative death occurred in the patient with right ventricular dominance. Only 1 patient has mild residual heart failure 4 months after operation. Clinically, mitral regurgitation is absent in 4 patients and, at most, mild in the other 4. No patient has a conduction disturbance. Repair of complete AV septal defect is facilitated by using separate patches for the ventricular and atrial components of the defect. Less distortion is created, and a more accurate reconstruction of a competent trileaflet mitral valve can be done.

Subacute bacterial endocarditis and complete endocardial cushion defect.

Subacute bacterial endocarditis involving the common atrioventricular (AV) valve is a rare complication of complete endocardial cushion defect. This report describes our experience with an 18-year-old patient who was seen with this problem. Diagnosis was established by two-dimensional echocardiography. The operative findings and technique of repair are described. We believe this to be among the first successful reports of complete repair of active endocarditis involving the common AV valve in this congenital anomaly.

Subclavian-pulmonary artery shunts with polytetrafluorethylene interposition grafts.

Systemic-pulmonary artery shunts remain an important treatment in cyanotic patients. Central shunts continue to pose early and late problems when standard Blalock-Taussig shunts are not possible. Twenty patients underwent subclavian-pulmonary artery shunt procedures with polytetrafluoroethylene (PTFE) prostheses between October, 1980, and August, 1982. Their ages ranged from 1 day to 15 years; 11 patients were less than 14 days old. The arterial oxygen tension rose from 30.7 +/- 11.9 mm Hg to 51.3 +/- 9.1 mm Hg (standard deviation; p less than 0.001) and from 26.4 +/- 7.5 mm Hg to 50.5 +/- 9.3 mm Hg (p less than 0.001) among the 11 neonates. There were no hospital deaths and only 2 late deaths (not shunt related). All patients have patent shunts and excellent relief of cyanosis. The 18 survivors have been followed for an average of 19 months (range, 7 to 29 months). No patient has required reoperation for shunt inadequacy or thrombosis. Recatheterization in 11 patients has demonstrated normal pulmonary pressures and good pulmonary artery growth without vessel distortion. Subclavian-pulmonary shunts using PTFE provide long-term palliation in cyanotic patients. This type of shunt appears to offer important advantages over other shunt procedures, including the classic Blalock-Taussig operation, in newborns.

Arterial repair for simple and complex forms of transposition of the great arteries.

Transposition of the great arteries (TGA) has traditionally been repaired by redirection of atrial flow. Concern over the late development of right ventricular and sinus node dysfunction has prompted increased use of the arterial repair. This approach was utilized in 11 patients ranging in age from 7 days to 22 months (mean 5.3 months) and in weight from 2.6 to 12.2 kg (mean 5.1 kg). Five patients had intact ventricular septum and underwent primary repair electively or after poor response to balloon atrial septostomy. A large ventricular septal defect (VSD) was present in 6 patients, one of whom had coarctation of the aorta and one with type B interrupted aortic arch. Pulmonary artery banding was done in 3 of these patients in addition to subclavian artery aortoplasty and primary arch repair. Spontaneous VSD closure occurred in 2 banded patients. All patients had normal coronary artery distribution. Conduits were not used in any repair. There were 2 operative deaths caused by injury to the right coronary artery prior to establishing bypass in one patient and to left ventricular (LV) failure in a patient operated on at 5 months of age with an LV pressure of only one-half systemic level. The 9 surviving patients are well from 4 to 38 months after operation (mean 15 months). No patient has congestive heart failure and 5 receive no medications. Catheterization in 4 patients revealed widely patent coronaries in each. Trivial aortic insufficiency was noted in 1 patient. Each had mild to moderate supravalvar pulmonary stenosis (12 to 51 mmHg). LV function was normal in each case.(ABSTRACT TRUNCATED AT 250 WORDS)

Childhood mitral valve prolapse.

Mitral valve prolapse is now the most common cardiac diagnosis of childhood. The auscultatory findings of a non-ejection click with or without an associated murmur of mitral insufficiency are reviewed and related to the pathologic and histologic abnormalities. Findings at presentation in a large series of patients are given. Potential problems with progressive mitral insufficiency, arrhythmias and bacterial endocarditis are reviewed. This overview attempts to establish the essentially benign nature of mitral valve prolapse in childhood while indicating areas where continued observation is necessary.