Dysplastic Valve Research Articles

Tetraploidy in Prenatal Diagnosis: “culture artifact” or clinical diagnosis?

In routine analysis of cultured CVS and amniotic fluid (AF) a few tetraploid cells are almost always observed. However, they are usually assumed to be due to culture artifact and are rarely documented in the laboratory report. In some CVS studies tetraploidy has retrospectively been reported as a “false positive” result. We present two cases which document the difficulty in interpreting tetraploidy.Case 1: AF was obtained at 40 weeks gestation from a fetus with multiple congenital anomalies. Interphase FISH analysis using probes for 13,18,21,X and Y was consistent with tetraploidy. Routine G banded analysis of cultured AF and fetal skin following delivery revealed only tetraploid metaphases. Congenital abnormalities in the infant were consistent with those previously reported in the literature.Case 2: CVS was performed at 12 weeks because of maternal age 39 and increased nuchal thickening. All 15 cells from long term culture were tetraploid while 5 cells from short term/direct preparation had a normal 46,XY karyotype. No tetraploid cells were found in cord blood following delivery while 4/30 metaphases from cultured umbilical cord were tetraploid. The infant's only congenital abnormality was a bicuspid dysplastic aortic valve with mild aortic stenosis.Conclusion: The clinical significance of mosaic and nonmosaic tetraploidy appears to be at least in part related to the type of tissue analyzed. The presence of nonmosaic tetraploid cells in uncultured amniotic fluid by interphase FISH appears to be a strong indicator of fetal abnormality. Mosaic diploidy/tetraploidy in CVS and cultured fibroblasts is of uncertain clinical significance.

Long-term invasive and noninvasive results of percutaneous balloon pulmonary valvuloplasty in children, adolescents, and adults

Background: Short-term and mid-term results of percutaneous balloon pulmonary valvuloplasty (BPV) are well known. However, data documenting long-term effectiveness of BPV are scarce. Methods and Results: The long-term results of 62 patients were assessed by catheterization and Doppler echocardiography 1 to 10 years (mean 6.4 ± 3.4) after BPV. Mean age of the patients was 13.5 ± 10.5 years (range 9 months to 44 years). Twenty patients were 16 years of age or older. Right ventricular peak systolic pressure was systemic or suprasystemic in 72% of patients. A double-balloon technique was used in 29 patients. The balloon–to–pulmonary valve diameter ratio was 1.4 ± 0.38 (range 1 to 1.8). Total systolic transpulmonary pressure gradient in excess of 50 mm Hg in all patients before BPV decreased from 98 ± 40 to 32 ± 23 immediately after BPV and to 19 ± 9 mm Hg at follow-up (P < .001). Infundibular gradient increased from 8 ± 10 to 14 ± 24 mm Hg after BPV and fell to 1 ± 4 mm Hg at follow-up (P < .01). In 16 patients it was ≥20 mm Hg and virtually disappeared spontaneously in all at follow-up. The valvar gradient fell from 93 ± 39 to 19 ± 11 (P < .001) and was 18 ± 9 mm Hg at follow-up. It remained unchanged in 3 patients (range 36 to 45 mm Hg). In 3 (4.8%) other patients, a new gradient >35 mm Hg developed that was ≥50 mm Hg in all 3. Among 5 patients having dysplastic valves, 3 had a gradient >35 mm Hg. There were no predictors of a gradient >35 mm Hg at long-term follow-up by univariate or multivariate Cox proportional hazards analysis. Mild to moderate pulmonary regurgitation was present in 39% of patients. On electrocardiography, right ventricular hypertrophy decreased significantly in 90% of patients. Conclusions: BPV as a treatment of typical pulmonic valve stenosis produces excellent long-term results. Restenosis is rare (4.8%) and occurs more frequently in patients with dysplastic valves. There is a constant spontaneous regression of associated infundibular obstruction. (Am Heart J 1999;138:950-4.)

Arterial switch in hearts with left ventricular outflow and pulmonary valve abnormalities

Background. Pulmonary valve and left ventricular outflow tract abnormalities (LVOT) may not be absolute contraindications to arterial switch operation (ASO). Methods. In this study we analyze long-term outcome for 26 such transposition patients (6.3% of our ASO cohort). Median age and weight were 69 days (7 to 3,631 days) and 4.5 kg (2.6 to 34 kg). Pulmonary valve abnormalities included bicuspid valve (n = 4) and dysplastic valve (n = 5). The LVOT abnormalities (n = 17) included accessory atrioventricular valve/endocardial cushion tissue, fibromuscular ring, anomalous muscle bands, and septal malalignment. Patients with dynamic LVOT obstruction were excluded. The median preoperative left ventricular to pulmonary artery peak systolic pressure gradient was 30 mm (0 to 93 mm), or 50 mm (16 to 93 mm) if patients with isolated valve abnormalities are excluded. The ASO was performed according to our standard technique with or without LVOT resection or pulmonary valvotomy as required. Results. There were two perioperative deaths (7.7%; 95% confidence interval, 0.9% to 25%), and no late deaths during 1,934 patient-months of follow-up time. Actuarial freedom from reoperation for neoaortic valve or LVOT problems is 87% (± 7) at 130 months, representing two reoperations. One was performed for neoaortic insufficiency plus LVOT obstruction, and the other for isolated LVOT obstruction. One patient currently has significant neoaortic insufficiency, and median gradient at last follow-up is 0 mm Hg (range, 0 to 35 mm Hg). Conclusions. The ASO can be performed in selected patients with transposition of the great arteries and with LVOT abnormalities with early and late survival and functional status similar to that of matched patients with normal pulmonary valves and LVOT ( p > 0.05), but with a greater hazard for reoperation ( p < 0.05). Selection for ASO should be based on anatomic criteria rather than left ventricular to pulmonary artery gradient alone, to avoid assigning these patients with transposition of the great arteries to treatment strategies less satisfactory than ASO.Transposition, arterial switch

Balloon Pulmonary Valvuloplasty

Since the initial description of balloon pulmonary valvuloplasty in 1982 by Kan and her associates, the procedure has been extensively used by several groups of workers for relief of pulmonary valve stenosis. It is generally recommended that the procedure be performed for peak‐to‐peak gradients in excess of 50 mmHg. Severe and critical obstructions, irrespective of age and pulmonary valve dysplasia, are amenable to balloon dilatation. The technique involves positioning one or more balloon catheters across the stenotic valve, usually over an extra‐stiff guidewire and inflating the balloons, thus producing valvotomy. The recommended balloon:annulus ratio is 1.2 to 1.4. Immediate reduction of gradient, increase in jet width, and free motion of the pulmonary valve leaflets with less doming have been observed following balloon dilatation. Improvement of right ventricular function, tricuspid insufficiency, and right‐to‐left shunt has also occurred. At intermediate‐term follow‐up, both catheterization measured peak‐to‐peak gradients and Doppler‐measured peak instantaneous gradients remain improved for the group as a whole. However, restenosis, defined as gradient ≥ 50 mmHg, has been observed in nearly 10% of children. Predictors of restenosis include balloon:annulus ratio ≥ 1.2 and immediate postvalvuloplasty gradient ≥ 30 mmHg. Small pulmonary valve annulus, earlier study year, and postsurgical complex pulmonary stenosis have also been identified as factors predictive of restenosis. Redilatation with balloons that are larger than those used at the time of initial balloon valvuloplasty produces excellent results, and redilatation is the procedure of choice in the management of restenosis after previous balloon pulmonary valvuloplasty. Regression of right ventricular hypertrophy on ECG following balloon dilatation has been well documented; ECG is a useful adjunct in the evaluation of results of balloon dilatation. However, ECG evidence for hemodynamic improvement does not become apparent until 6 months after balloon dilatation. Doppler gradient is generally reflective of residual obstruction and is a useful and reliable noninvasive monitoring tool. Infundibular gradients occur in nearly 30% of patients: the older the age and higher the severity of obstruction, the higher the prevalence of infundibular reaction. When residual infundibular gradient is ≥ 50 mmHg, beta blockade therapy is generally recommended. The infundibular obstruction regresses to a great degree at follow‐up with the rare patient requiring surgical intervention. While there is some controversy with regard to use of balloon dilatation in patients with dysplastic pulmonary valves, based on our own observations and those of others, the results of balloon valvuloplasty with dysplastic pulmonary valves are comparable to those without. Dysplastic valves did not seem to be responsible for recurrence, and balloons large enough to produce balloon:annulus ratio of 1.4:1.5 may be needed to produce a satisfactory result. Comparison with surgical valvotomy has limitations, but generally there is greater reduction of gradient following surgery, but the degree and frequency of pulmonary insufficiency may be higher following surgery than after balloon therapy. Long‐term follow‐up results are scanty, but the data from our cohort reveal minimal additional restenosis, event‐free rates of 88% and 84% at 5 and 10 years, respectively, and significant increase in the prevalence of pulmonary insufficiency. But, no surgical intervention was warranted for pulmonary insufficiency in any patient following balloon dilatation. In conclusion, balloon pulmonary valvuloplasty is the treatment of choice for relief of pulmonary valve stenosis. Use of balloons 1.2‐1.4 times larger than pulmonary valve annulus may produce optimal results. Ten‐ to 20‐year follow‐up to identify the significance of residual pulmonary insufficiency is indicated.

Repair of congenital tricuspid valve abnormalities with artificial chordae tendineae

Background. Congenital abnormalities of the tricuspid valve, including Ebstein’s malformation, dysplasia, straddling, and those found in pulmonary atresia with intact septum and congenitally corrected transposition, are an uncommon cause of tricuspid regurgitation. Congenital tricuspid valve anomalies are found as a spectrum of disease in which both the leaflets and the subvalvar apparatus are often involved. Tricuspid valve repair is complicated in such patients because the chordae tendineae are often abnormally short and thick. Replacement or augmentation of chordae tendineae has proved to be a useful component of mitral valve repair. In the present report, we describe the techniques and results of chordal augmentation in the repair of congenital tricuspid valve abnormalities. Methods. Since July 1992, tricuspid valve repair has been performed in 5 children with severe tricuspid regurgitation secondary to congenital abnormalities of the tricuspid valve with significant chordal pathology. As a component of the repair, chordal replacement or augmentation was performed using expanded polytetrafluoroethylene suture. Results. Intraoperative and postoperative echocardiographic assessment showed good mobility of the tricuspid valve leaflets and trivial to mild tricuspid regurgitation. There were no complications and no early or late mortality. At follow-up of 34 to 60 months (median, 49 months), tricuspid valve function has remained excellent in 4 of the 5 patients. In the remaining patient, progressive regurgitation of the right ventricle to pulmonary artery allograft conduit has led to right ventricular dilatation, with a secondary increase in tricuspid regurgitation from trivial to moderate. Conclusions. Chordal replacement or augmentation with expanded polytetrafluoroethylene suture is a useful technique in the repair of congenitally dysplastic tricuspid valves with abnormal chordal structures.

Long-Term Results After Repair of Complete Atrioventricular Septal Defects: Analysis of Risk Factors

Background. We analyzed data from 320 patients to evaluate the impact of different preoperative, operative, and postoperative factors on the outcome after repair of complete atrioventricular septal defect.Methods. Between October 1974 and December 1995, 320 patients with complete atrioventricular septal defect not associated with major cardiac anomalies were operated on. Two hundred seventy-four patients underwent total repair. Sixty-three patients (23%) were less than 6 months old. One hundred ninety-eight (72.2%) underwent primary repair. Seventy-six patients (27.7%) had a previous palliative operation.Results. Operative mortality in patients who underwent primary repair decreased from 17.6% (1974 to 1979) to 5.0% (1990 to 1995) despite an increase in the number of patients younger than 6 months. In patients undergoing a two-stage procedure operative mortality was 3.9% (late mortality, 7.9%). Young age (<6 months) was an incremental risk factor (p = 0.008) for operative mortality in the early study period. Coarctation of the aorta (p = 0.02) and severe dysplastic left atrioventricular valve (p = 0.001) were associated with a higher risk for operative mortality. Freedom from reoperation at 10 years was 82.5% ± 3.8%.Conclusions. In patients with complete atrioventricular septal defect, primary repair is the treatment of choice and can be accomplished with good results. In our experience over a period of more than 20 years, earlier date of operation, young age (<6 months), dysplastic left atrioventricular valve, and coexisting coarctation were incremental risk factors for hospital death. The presence of a previously placed pulmonary artery band did not alter the outcome of repair. The reconstructed atrioventricular valve shows a good and long-lasting performance.

The morphologically tricuspid valve in hypoplastic left heart syndrome

Competence of the tricuspid valve is crucial for survival of children with hypoplastic left heart syndrome. We studied the morphology and topology of the valvar and subvalvar structures, trying to identify abnormalities which could impair valvar function. A total of 82 specimens with hypoplastic left heart syndrome were examined pathologically. Measurements of valvar dimensions were taken, significant dysplasia of the valvar leaflets was noted and the muscular and tendinous supporting structures determined. The findings were correlated to the subgroups of hypoplastic left heart syndrome. Of the hearts, 10 (12%) showed a bileaflet right atrioventricular valve, 27 (33%) a moderately and 2 (2%) a severely dysplastic tricuspid valve. The majority of the abnormalities was found in hearts with a patent mitral valve. In 79% of the hearts with mitral atresia, the septal surface was concave instead of convex to the right ventricular lumen and the direct tendinous attachments of the septal leaflet replaced by a multitude of freestanding papillary muscles. The number of direct septal attachments was significantly higher in hearts with a patent mitral valve. The tricuspid valve in hypoplastic left heart syndrome can differ from the valve seen in normal patients. The subvalvar apparatus is different in hearts with mitral atresia, whereas dysplasia of the leaflets occurs more often together with mitral stenosis. These features should be considered in reconstructive operations as well as during diagnostic procedures.

Angiographic and morphologic features of the left ventricle in Ebstein's malformation

Quantitative and qualitative cineangiographic analysis of the left ventricle (LV) was performed in 26 patients with isolated Ebstein's malformation, having a mean age of 23 ± 17 years. Nine autopsied hearts with isolated Ebstein's malformation were submitted to morphologic and morphometric analysis. In 4 of the cases, it was possible to make a direct correlation between the angiographic data obtained during life and the autopsy findings. On the basis of the LV end-diastolic volume we identified 3 groups of patients: 7 with volume <60 ml/m 2, another 7 with volume between 60 and 80 ml/m 2, and 12 with volume >80 ml/m 2. The LV ejection fraction was reduced in 2 patients with normal LV enddiastolic volume and in 6 with increased LV end-diastolic volume. The ratio of ventricular mass to LV end-diastolic volume was always adequate, but a reduction of the ventricular contractive performance (end-systolic pressure to end-systolic volume ratio <3 mm Hg/ml/m 2) was found only in patients with a dilated left ventricle. No correlation was demonstrated between the extent of the atrialized component of the right ventricle (mean value 67 ± 31 cm 2, range 13 to 133) and the LV dimensions. All but 2 patients showed a leftward diastolic displacement of the ventricular septum, but in only 1 did this produce an elongated shape of the left ventricle. Sixteen had anomalies of LV dynamics: 10 with hypokinesia (3 of the posterior wall, 4 of the apex, 1 of the inferior wall, 1 of the septum, and 1 global), 6 with dyskinesia (1 of the posterior wall, 2 of the apex, 1 of the posterior wall and apex, 1 of the superior part of the septum, and 1 of the anterior wall), and 8 with premature diastolic distension of the anterobasal wall. Morphometric analysis produced mean values for myocytes of 59 ± 10%, for the interstitium of 21 ± 4%, and for fibrous tissue of 20 ± 9% (normal 4 ± 1%). Five autopsied hearts had a prolapsing and/or dysplastic mitral valve.

Results of left atrioventricular valve reconstruction after previous correction of atrioventricular septal defects.

The objective of this study was to determine causes of severe left atrioventricular (AV) incompetence and the factors leading to the success of valve repair later after correction of atrioventricular septal defects (AVSD). A total of 28 patients aged 5 months to 38 years (mean age 6.7 years) were operated for significant (grade II-III) left AV valve incompetence (LAVVI), two months to twenty-five years (median 1.5 years) after correction of complete (11 patients) or partial atrioventricular septal defects. Fourteen patients had initially undergone surgery during infancy. At reoperation a completely open or partially sutured cleft was found in 16 patients combined with dysplastic valve tissue in four cases, with a fibrotic valve in three cases, with posterior leaflet prolapse in two cases, with a double orifice valve in three cases, and a parachute valve in two cases. Partial or complete reopening of a previously sutured cleft caused by suture dehiscence was found in 12 cases combined with a fibrotic valve in five cases, with a dysplastic valve in one case and with severe deformity of valve in one case. A combination of these anomalies was observed in seven patients in both groups. Left atrioventricular valve repair including cleft closure combined with annuloplasty and other surgical procedures resulted in the disappearance or significant diminishing of LAVI in 18 patients (64%). Severe SAVI persisted in six patients, five of them exhibiting a combination of several additional left AV valve anomalies (fibrotic or dysplastic valve, parachute valve). Five of these six patients underwent successful left AV valve replacement with a mechanical prosthesis 7 days to 2 years after reoperation. The presence of additional left AV valve anomalies was the single statistically significant factor for recurrent major LAVVI after reoperation (P = 0.0106). There were two postoperative deaths in patients with mild LAVVI after surgery, and no late deaths. An open cleft is the major factor of late severe SAVVI after correction of AVSD. Although suturing the cleft in conjunction with performing annuloplasty improved valvular function in most of the cases, the presence of severe left AV valve anomalies increased the risk of recurrent LAVVI and the need for valve replacement, thus playing a major role in determining the outcome of valve reconstruction in patients after reoperation.

Atrio-ventricular valve dysplasia in 22 newborn infants

We retrospectively studied the experience of our institution with isolated dysplasia of one or both atrio-ventricular valves in 22 newborn infants. All patients with associated cardiac malformations were excluded. Ten patients exhibited isolated tricuspid valve dysplasia. One patient had tricuspid valve dysplasia and a dysplastic pulmonary valve. In 10 patients, both atrio-ventricular valves were affected. Finally, mitral valve dysplasia was associated with pulmonary valve stenosis in 1 case. Associated syndromes and/or chromosomal anomalies were: Down syndrome ( n=2), trisomy 18 ( n=1), Noonan syndrome ( n=1), Marfan syndrome ( n=3), Ehlers-Danlos and Cutis laxa ( n=2). Mortality was 27.2% during follow-up (mean 51 months): 3 patients with chromosomal aneuploidies, 2 patients with severe neonatal Marfan syndrome and 1 with Ehlers-Danlos. Complications were: sustained supra-ventricular tachycardia in 3, neonatal staphylococcal tricuspid valve endocarditis in 1, persistent significant valvular disease in 8. In the remaining 9 survivors, the dysplasia of the atrio-ventricular valves persists with absent or mild incompetence. Beside obvious chromosomal anomalies, newborn infants with dysplastic valves should be investigated for manifestations of connective tissue disorders. This may help to identify new pleiotropic syndromes which include valvular dysplasia as one manifestation.

Successful percutaneous double balloon valvuloplasty for congenital mitral stenosis

A 19-month-old infant had an isolated severe ‘typical’ congenital mitral stenosis with dysplastic valves and two symmetric papillary muscles. He underwent successful double balloon mitral valvuloplasty via the right femoral vein. Left atrium pressure decreased from 30 to 20 mmHg and end diastolic mitral gradient from 12 to 0 mmHg. Cardiac index increased from 4.4 to 6.3 l/min per m 2. Gorlin's mitral valve area increased from 1 to 1.7 cm 2/m 2 and Doppler mitral valve area from 0.9 to 2.2 cm 2/m 2. At 16 months follow-up, the infant showed sustained clinical improvement.

Correction of complete atrioventricular septal defects with the double-patch technique and cleft closure

Controversy continues to surround determining which is the most beneficial method of complete atrioventricular septal defect repair, eg, one- versus two-patch repair, closure of mitral cleft, and the necessity of annuloplasty. Between January 1988 and November 1995, 120 patients with complete atrioventricular septal defect underwent total correction at the German Heart Institute Berlin. Sixty-nine of the patients were infants and 51 were children or adolescents. Eleven patients had previously undergone pulmonary artery banding. One hundred three patients had Down's syndrome. In all 120 patients complete atrioventricular septal defect repair was performed using the two-patch technique. The mitral cleft was closed with interrupted sutures in 119 cases. Thirty-four patients required aggressive treatment of postoperative pulmonary hypertensive crises (including nitric oxide inhalation). There were 12 hospital deaths (10%). Mortality was highest in patients with persistently high postoperative pulmonary arterial pressure (pulmonary artery pressure/systemic artery pressure > 0.6) (7 of 17 patients died; 41%). Associated atrioventricular valve anomalies, especially dysplastic valve tissue and severe preoperative cardiopulmonary instability necessitating catecholamine support and artificial ventilation, represented other risk factors. There were six late deaths (5%); cumulative mortality was 15%. Four patients suffered a complete heart block and sick sinus node syndrome necessitating pacemaker implantation 1 to 6 months after operation. During the follow-up period (3 to 80 months after operation), 7 patients (6.8% of survivors) were successfully reoperated on after significant mitral valve incompetence due to an open "cleft" (suture failure) developed. Correcting complete atrioventricular septal defect using the two-patch technique, routine cleft closure, and atrial septal incision led to a low incidence of residual mitral valve incompetence. Mortality was primarily influenced by severe cardiopulmonary instability and additional atrioventricular valve anomalies preoperatively and the persistence of high pulmonary arterial hypertension postoperatively.

Transposition of the great arteries complicated by tricuspid valve incompetence

Tricuspid valve insufficiency secondary to structural anomalies of the valve itself or to an iatrogenic complication of the Rashkind procedure is very rarely associated with transposition of the the great arteries. This condition represents an interesting perioperative challenge. Rapid restoration of the tricuspid valve to a low-pressure system by arterial switch operation associated with tricuspid repair should theoretically improve the outcome in terms of myocardial and valve function. Thirteen of 839 patients who underwent an arterial switch operation for various forms of transposition of the great arteries presented with moderate to severe tricuspid insufficiency. Three of them had a ventricular septum defect. Nine experienced severe cardiac failure with profound hypoxemia. Ventilatory support was necessary in 7, 6 had renal or hepatic dysfunction, and 5 had coagulation disorders. Inotropic support was started preoperatively in 8 patients. Tricuspid lesions were as follows: primary annular dilatation and lack of coaptation at the commissural level (n = 1), straddling tricuspid valve (n = 1) redundant tricuspid valve tissue leading to left ventricular outflow tract obstruction (n = 1), small cleft of the septal leaflet (n = 1), and dysplastic valve tissue with juxtacommissural regurgitation (n = 1). In 8 patients, the cause of the tricuspid valve insufficiency was most probably an iatrogenic lesion, with rupture of the papillary muscle (n = 2), rupture of the chordae (n = 1), or tear of the anterior leaflet (n = 5), whereas no clear cause could be found in 1 patient. Repair consisted of the arterial switch operation associated with tricuspid valve repair in 10 patients. In 2 patients with only discrete anomaly and in 1 without a clear cause of tricuspid regurgitation, no valve repair was performed. Three patients had their ventricular septal defect closed. There were only one early and one late death, both not related to the tricuspid lesions. Late postoperative (mean, 6.5 years) evaluation revealed normal left ventricular function in 10, with no tricuspid incompetence in 7 and trivial tricuspid insufficiency in 3. Restoration of an incompetent tricuspid valve in a low-pressure system by the arterial switch operation combined with valve repair provides good ventricular and valvar results. Preoperative management and appropriate timing of operation seem to be of utmost importance.

Repair of tetralogy of Fallot in the first six months of life: Transatrial versus transventricular approach

This report describes our experience with primary correction of tetralogy of Fallot in infants. Fifty-one consecutive infants younger than 6 months underwent primary correction of tetralogy of Fallot between January 1978 and October 1994. Mean age at repair was 4.2 months. Four were neonates. Correction was accomplished through a right ventriculotomy in the first consecutive 22 patients (43%; group A); since 1991, a combined transatrial-transpulmonary approach was used in 29 consecutive patients (57%; group B). A transannular patch was necessary in 33 infants (65%) 16 of group A (73%) and 17 of group B (59%). There was one early death from possible left anterior descending coronary artery distortion in group A and no deaths in group B. Two patients required early reoperation for systemic-to-pulmonary artery collateral ligation (postoperative day 6) and permanent pacemaker implantation (postoperative day 30). There were no late deaths. All 50 survivors are currently asymptomatic and in New York Heart Association class I. Three patients required late reoperations 36 months, 30 months, and 13 months after repair for (1) subaortic stenosis and dysfunctioning dysplastic mitral valve, (2) residual pulmonary artery branch stenosis, and (3) residual right ventricular outflow obstruction. Four patients underwent balloon dilation and stent insertion (1 patient) for peripheral pulmonary artery stenosis 1.5 year to 12 years (mean, 5 years) after initial repair. Actuarial freedom from need for reintervention at 4 years was 78.4% in group A and 85.7% in group B. Two-dimensional and Doppler echocardiographic follow-up studies showed a residual mild to moderate pulmonary artery branch stenosis in 4 patients in group A, and a recurrent subaortic stenosis in 1 patient in group A. Right ventricular peak systolic pressure was less than 40 mm hg in all but 3 asymptomatic patients who had a residual pulmonary artery branch stenosis. Right ventricular end-systolic and end-diastolic volumes showed larger volumes and reduced ejection fraction in group A compared with group B. This limited experience with repair of tetralogy of Fallot in patients less than 6 months of age demonstrates that the transatrial-transventricular approach is possible in neonates and young infants with a very low mortality and morbidity and also a low incidence of residual lesions. Follow-up echocardiographic data suggest that right ventricular function is better preserved in those patients who underwent the transatrial-transpulmonary repair.

Valvar aortic stenosis

Valvar aortic stenosis is a progressive lesion that constitutes 2% of congenital heart disease in neonates and 11 % in young adults. Fusion of the commissures results in a stenotic valve, which is usually tricuspid or bicuspid but rarely unicuspid or quadricuspid. The valve leaflets may be thick and, on rare occasions, the annulus is small. The pressure gradient is proportional to the flow squared. To estimate valvar stenosis, one must calculate the valve area. Left ventricular hypertension stimulates cellular hyperplasia and causes a shift in myosin isozyme and left ventricular hypertrophy. This results in a significant increase in left ventricular contractility; therefore, most children have a normal exercise tolerance. The myocardial oxygen supply/demand (diastolic pressure time index × 02 content/tension time index) ratio is an index of myocardial oxygenation. This ratio decreases significantly in patients with severe aortic stenosis and causes subendocardial ischemia. The neonate with severe valvar aortic stenosis is quite ill and shows signs of hypoperfusion and severe respiratory distress. The heart sounds are muffled and the systolic murmurs may be short or absent. In older infants and children, long and highpitched systolic murmurs in the aortic valve region suggest severe valvar aortic stenosis. Chest pain, fainting, and unexpected sudden death occurs in patients with severe valvar aortic stenosis (valve area <0.60 cm 2/m 2). Echo Doppler studies are diagnostic procedures that eliminated the need for diagnostic cardiac catheterization except in infants with multiple lesions. In most children, cardiac catheterization is only performed when a balloon aortic valvuloplasty is indicated. Indications for cardiac catheterization include a Doppler gradient >60 mm Hg, fainting, arrhythmias, exertional angina, and electrocardiographic changes suggestive of subendocardial ischemia. Congestive heart failure is seen in neonates, and treatment with digitalis and diuretics is indicated. Surgery or balloon aortic valvuloplasty are indicated for severe stenosis or moderate stenosis with symptoms of chest pain, arrhythmias, or electrocardiographic findings of subendocardial ischemia. Neonates with left ventricular end-diastolic volume <20 mL/m 2 or left ventricular cross-sectional area <1.7 cm 2 are at high risk and do poorly. Patients with small aortic valve anuli require surgical anuloplasty. Those with very thick dysplastic valves or moderate to severe aortic valve regurgitation require valve replacement. All other patients are good candidates for balloon aortic valvuloplasty. The degree of mortality, morbidity, patient discomfort, financial cost, relief of stenosis, and induction of aortic valve regurgitation seen with balloon aortic valvuloplasty compare favorably with surgical valvotomy.

Truncal valve repair: Initial experience with infants and children

The truncal valve regurgitation that frequently arises in patients with truncus arteriosus accounts for increased operative and late mortality. Five patients underwent truncal valve repair at UCLA Medical Center between August 1990 and September 1991. This group consisted of 2 infants who underwent complete repair and 3 who underwent valve repair together with right ventricle-pulmonary artery conduit replacement. The techniques used for repair were individualized according to the specific valve morphology, and consisted of the suturing of partially developed commissures, suspension of the cusps, resection of redundant portions of the cusps, annuloplasty at the commissures, and resection of excrescences on the surface of valve leaflets. In 1 infant who had a severely dysplastic truncal valve, stenosis and regurgitation recurred and progressed, and he died 4 months after truncal valve replacement. The remaining 4 patients, who were followed for from 8 to 21 months after repair, are in New York Heart Association class I, and have minimal or no aortic regurgitation. Except in patients with severely deformed and dysplastic valves, truncal valve repair can be an attractive and successful alternative to valve replacement.

Spectrum of valvar abnormalities in Noonan's syndrome—a pathologic study

AbstractFour patients with the phenotypic characteristics of Noonan's syndrome presented in infancy with a suspected cardiac defect. The cardiac segmental connections were normal. All four were diagnosed to have valvar pulmonary stenosis by cross-sectional echocardiography, the valve being typically thickened and dysplastic as expected for the syndrome. In addition, all had hypertrophic cardiomyopathy and evidence for important abnormalities of the other cardiac valves. Two of the four patients died following cardiac surgery. Of the other two, one child died during interventional catheterization and another died while awaiting cardiac surgery. The cardiac abnormalities, confirmed at postmortem, were dysplastic pulmonary valve with stenosis (four patients), dysplastic aortic valve (three patients), supravalvar aortic stenosis (one patient), small and dysplastic tricuspid and mitral valves (four patients), hypertrophic obstructive cardiomyopathy affecting both ventricles, with asymmetric septal hypertrophy (four patients), atrial septal defect within the oval fossa (one patient). In addition to the usually described abnormalities of the pulmonary valve and ventricular myocardium, the patients described showed a wide spectrum of valvar dysplasia which has received little attention in the past. If these patients do indeed have Noonan's syndrome, and the evidence supports this contention, then these findings support the hypothesis of a more generalized disorder in the development of the ventricles and valves in the syndrome, which has a variable expression. They also stress the need to look carefully for abnormalities of valves other than the pulmonary valve in patients who present with symptoms in infanscy.

Severe mitral insufficiency in mucopolysaccharidosis type III-B (Sanfilippo syndrome)

A 6-year-old girl with mucopolysaccharidosis (MPS) III-B (Sanfilippo syndrome) who developed severe mitral regurgitation and congestive heart failure requiring surgery (valvuloplasty) is reported. One year after surgery the patient remains well, with marked improvement in her physical activity, and without signs of heart failure. This is only the second report of severe mitral regurgitation in MPS III, and is the first report of a successful repair (valvuloplasty) of a dysplastic mitral valve in the MPS. Mitral valvuloplasty should be considered instead of valve replacement in any MPS patient with mitral valve regurgitation requiring surgery.

Neonatal Tricuspid Insufficiency with Abnormal Tricuspid Valve Treated with Extracorporeal Membrane Oxygenation (ECMO): Possible Extension of ECMO Use

Extracorporeal membrane oxygenation is now an accepted method of treatment for neonatal hypoxemia due to a number of causes. We extend the indications of ECMO to hypoxemia secondary to dysplastic tricuspid valve. We report the case of a neonate with congenital dysplastic tricuspid valve who responded to ECMO.

Five-year follow-up after balloon pulmonary valvuloplasty

Objectives. The aim of this study was to assess results 5 years after balloon pulmonary valvuloplasty.Background. Since the technique of balloon pulmonary valvuloplasty was first reported in 1982, it has become the treatment of choice for pulmonary valve stenosis. In contrast to surgical valvotomy, the long-term outcome after balloon pulmonary valvuloplasty is unknown.Methods. We reviewed the findings in 34 patients 5.2 ± 0.8 (mean ± SD) years after balloon pulmonary valvuloplasty: 27 with isolated pulmonary stenosis, 5 with Noonan syndrome and 2 with previous surgical valvotomy. In eight patients (three with Noonan syndrome), a second balloon valvuloplasty was the index procedure for analysis,Results. The transpulmonary gradient (mm Hg) was 74 ± 34 before balloon pulmonary valvuloplasty, 36 ± 26 Immediately after, 22 ± 9 at cardiac catheterization in 29 patients 6 ± 0.6 months later and 19 ± 10 by Doppler study at 5 years. At 5 years 26 patients (group A) had a residual gradient of ≤20 mm Hg; the remaining 8 (group B) had a gradient of >20 mm Hg. Four group B patients had Noonan syndrome (p = 0.01). Balloon/pulmonary valve diameter ratio was larger for group A patients than for group B patients with isolated pulmonary stenosis (1.20 ± 0.10 vs. 1.00 ± 0.07, p = 0.005); larger balloons were used in group B patients with Noonan syndrome (1.30 ± 0.10). Group A patients were more likely than group B patients to have significant pulmonary incompetence (6 of 24 vs. 0 of 8) and had a greater right ventricle/left ventricle long-axis diastolic dimension ratio (0.47 ± 0.10 vs. 0.35 ± 0.04, p - 0.05). In the subgroup of five patients with Noonan syndrome and two with prior surgical valvotomy, the transpulmonary gradient was reduced from 74 ± 24 mm Hg before balloon valvuloplasty to 23 ± 12 mm Hg at 5 years. In addition, two patients with isolated pulmonary valve stenosis had pulmonary valve dysplasia by angiographie criteria: transpulmonary gradients of 85 and 56 mm Hg were reduced to 20 and 11 mm Hg, respectively, at 5 years.Conclusions. Relief of obstruction persists at 5 years especially if oversized balloons are used. Acceptable results can be obtained in patients with a dysplastic valve. More complete relief of right ventricular outflow gradient is associated with Increased right ventricular dimension, probably because more pulmonary incompetence is induced. This is well tolerated at 5 years but may be important in the longer term.