Left ventricular growth in selected hypoplastic left ventricles: outcome after repair of coarctation of aorta.

BACKGROUND: Models that predict survival in neonates with left ventricular hypoplasia and critical aortic stenosis may not be applicable to neonates with left ventricular hypoplasia and coarctation. METHODS AND RESULTS: We report 8 infants with severe aortic coarctation and left ventricular hypoplasia. Mean age was 18 days (range 1-48 days), and mean weight was 3.5 kg (range 2.7-4.3 kg). Associated diagnoses included mild aortic stenosis (4), ventricular septal defect (2), and venous anomalies (2). All had coarctation repair as a primary procedure (3 of these had concomitant intracardiac procedures); 7 had subsequent operations. All are alive and well 1.1-6.7 years (mean 3.1 years) after the first surgery. Progressive increases were observed in aortic and mitral diameters, and in left ventricular dimensions, areas, and volumes when the preoperative, earliest postoperative, and most recent echocardiograms were compared. CONCLUSIONS: Despite severe left ventricular hypoplasia, a two-ventricle repair is possible in selected cases. The prognostic criteria for left ventricular hypoplasia in critical aortic stenosis may not be applicable to infant coarctation. Relief of coarctation may result in the growth of the very small left ventricle, especially when the aortic root and mitral diameters are satisfactory.

Double-horned or caplike right ventricle: diagnosis and operative treatment.

BACKGROUND: Three patients reported here and 4 from the literature serve as background for the state-of-art diagnostic and operative considerations for an unusual congenital cardiac malformation: double-horned or caplike right ventricle. METHODS: This is a retrospective analysis of cardiac catheterization, cineangiography, and two-dimensional echocardiography findings, as well as palliative and corrective operations in 3 previously unreported patients. Four patients from the literature are reviewed. RESULTS: Characteristic morphologic features recognizable by invasive and noninvasive imaging distinguish double-horned right ventricle from complex malformations such as criss-cross hearts, superior-inferior ventricles, and univentricular hearts with a small outflow chamber. CONCLUSION: Double-horned or caplike right ventricle is a congenital malformation characterized by an unusual ventricular morphology, which may be the result of incomplete development of the right ventricle. The two-horned appearance may be secondary to an absence of the apical trabeculated compartment, with the left ventricle wedged between the two horns. It is invariably associated with double right ventricular outlet. Surgical experience so far suggest that most patients with typical double-horned right ventricle should be considered for anatomic surgical correction.

Transmission of full-length echocardiographic images over ISDN for diagnosing congenital heart disease.

OBJECTIVES: To study the feasibility of transmitting full-length diagnostic-quality echocardiograms with video conferencing systems linked by ISDN. METHODS: Forty-three previously video-recorded full-length echocardiograms (22 complete two-dimensional Doppler studies, 21 separate M-mode studies) were transmitted from a site 30 miles distant using desktop video conferencing systems linked with one ISDN line (128 kbps). Blinded interpretations of the original recorded and transmitted studies were made by two pediatric cardiologists (two-dimensional Doppler) and a pediatric sonographer (M-mode). RESULTS: Diagnoses of normal (N = 12) and abnormal (N = 10) conditions were made from the original tapes; the same interpretations were made from the transmitted studies. Twenty-one specific abnormalities in the 10 abnormal studies were seen on both original and transmitted videotapes. These abnormalities ranged from simple congenital heart defects, including ventricular septal defect, atrial septal defect, and patent ductus arteriosus, to complex ones, such as coronary artery fistula, double-outlet right ventricle, and complete atrioventricular canal. Qualitatively, there was mild degradation in gray scale, brightness, and contrast of the images. Six M-mode variables from the transmitted images had excellent concordance with the original tracings (P = 0.506 to 0.838; r = 0.86 to 0.97). CONCLUSIONS: Although our sample size was small, this preliminary experience indicates that video conferencing equipment utilizing ISDN technology is a reliable method for transmitting full-length diagnostic-quality echocardiographic studies from remote sites. This technology may have a significant impact on the management of pediatric patients with suspected heart disease. Further evaluation is warranted.

Repair of complete atrioventricular canal defects: results with the two-patch technique.

BACKGROUND: Between 1983 and 1994, 115 infants and children underwent repair of a complete atrioventricular canal defect with the two-patch technique and routine mitral valve "cleft" closure. METHODS: A retrospective review of these 115 patients was performed. Age at the time of repair ranged from 1 month to 108 months (mean age, 14.2 +/- 16.5 months; median age, 8 months). Preoperative cardiac catheterization in 113 patients revealed a mean pulmonary to systemic flow ratio of 3.37 +/- 1.8, a mean pulmonary artery systolic pressure of 71.1 +/- 15.7 mm Hg, and a mean pulmonary vascular resistance of 4.9 +/- 3.3 units. Associated anomalies included Down's syndrome (99 patients), patent ductus arteriosus (47), and coarctation of the aorta (4). Rastelli classification was A (76 patients), B (10), C (24), and unknown (5). Twenty-four patients had intraoperative epicardial or transesophageal echocardiography. RESULTS: Although there was a trend toward increasing mean preoperative pulmonary vascular resistance with age from 2.1 +/- 0.9 units (0 to 3 months) to 4.0 +/- 2.6 units (4 to 6 months) to 5.7 +/- 3.0 units (7 to 12 months), the mean pulmonary vascular resistance of each age group was not significantly different from that of the main group. The operative survival rate was 94% (seven early deaths) and the overall survival rate, 91% (three late deaths). Intraoperative echocardiography altered the surgical therapy for 1 patient. No patient has required reoperation for a residual ventricular septal defect. Four patients (3.5%) had heart block requiring permanent pacemakers. Eight patients (7%) required reoperation for mitral insufficiency; 6 of whom had successful repair of a residual cleft. CONCLUSIONS: For infants with complete atrioventricular canal defect, repair using the two-patch technique with routine mitral valve cleft closure at 4 to 6 months of age results in a low operative mortality, a low incidence of permanent heart block, and a low reoperation rate for mitral insufficiency.

Prospective detection by Doppler color flow imaging of additional defects in infants with a large ventricular septal defect.

The use of Doppler color flow imaging and axial contrast angiography in the preoperative detection of additional ventricular septal defects (in the setting of a known large defect) were compared in a prospective fashion. One hundred seventy-nine infants with two ventricles (each of at least normal size) and a large, nonrestrictive ventricular septal defect underwent reparative surgery before 2 years of age. The reference standard for the presence of additional defects was intraoperative verification or (in cases in which the surgeon did not visualize any additional defect) subsequent identification at postoperative angiography, postoperative color Doppler examination or reoperation. Only six patients (3%) had additional ventricular septal defects confirmed at the time of repair; an additional five (3%) had defects found only postoperatively. The negative predictive value of Doppler color flow imaging and angiography was 0.95 (168 of 176) and 0.97 (168 of 174), respectively. The sensitivity was 0.27 (3 of 11) and 0.45 (5 of 11), respectively. For certain malformations with a very low prevalence of additional muscular defects (such as perimembranous ventricular septal defect with normally aligned great arteries), a clinical trial of reparative surgery without prior invasive study appears reasonable.

Safety and utility of endomyocardial biopsy in infants, children and adolescents: a review of 66 procedures in 53 patients.

The benefits and risks of endomyocardial biopsy in infants, children and adolescents were determined by reviewing the indications for and complications and results of 66 procedures in 53 patients aged 2 months to 20 years. One patient had a pneumothorax, and three had a right ventricular perforation. Ventricular tachycardia developed in four patients; it was treated with lidocaine in three and was self-limited in one. The procedure was unsuccessful in two patients. Among 25 patients with a prebiopsy diagnosis of idiopathic dilated cardiomyopathy, microscopic features were consistent with cardiomyopathy in 24 (96%) and were normal in 1. Of nine patients with clinically suspected myocarditis, only two (22%) had microscopic evidence of inflammation, and seven had chronic nonspecific features suggestive of dilated cardiomyopathy. Of eight patients with unexplained arrhythmias, six (75%) had microscopic findings compatible with dilated cardiomyopathy and two had myocarditis. Biopsy tissue samples from seven patients with nondilated forms of cardiomyopathy (four hypertrophic, three restrictive) were consistent with the clinical diagnosis in six and were inadequate in one. Cardiac biopsies were also performed in four patients with other disorders. Among the 51 patients with adequate biopsy specimens, microscopic features were considered diagnostic in 5, confirmatory in 44 and not helpful in 2 with normal tissue. The results indicate that endomyocardial biopsy is safe in infants, children and adolescents. It is useful for the evaluation of cardiomyopathy and specific secondary forms of myocardial disease. There seems to be little correlation, however, between clinical and tissue diagnoses of myocarditis.

Pulmonary artery configuration after palliative operations for hypoplastic left heart syndrome.

Pulmonary artery architecture and symmetry after palliative operations for hypoplastic left heart syndrome may affect subsequent suitability for a modified Fontan operation. Two-dimensional echocardiography was used to measure pulmonary artery diameter and assess symmetry after two types of systemic-pulmonary artery shunts: modified right Blalock-Taussig shunt (14 patients) and central shunt (from underside of aortic arch gusset to pulmonary artery confluence) (14 patients). Age, weight, preoperative diameter of right and left pulmonary arteries (proximal, middle, and distal segments), and mean interval between preoperative and postoperative echocardiographic studies (20.2 +/- 4.4 days in the Blalock shunt group; 19.1 +/- 6.8 days in the central shunt group) were similar. Early postoperatively, patients with a Blalock shunt showed a significant decrease in the diameter of all pulmonary artery segments except the distal right pulmonary artery. The diameters tapered from distal right to distal left pulmonary artery in this group. Patients with the central shunt had a significant decrease in the diameter of all pulmonary artery segments. There were no significant differences when cross comparisons were made of the various pulmonary arterial segments in patients after a central shunt. Similar findings persisted in 19 patients from both groups who had a late postoperative echocardiogram (mean interval between studies = 271 days in the group of 10 patients with Blalock shunt and 167 days in the group of nine patients with a central shunt). In conclusion, the central shunt preserves pulmonary artery symmetry, which may be important in candidates for the Fontan operation in infancy.

Fate of the pulmonic valve after proximal pulmonary artery-to-ascending aorta anastomosis for aortic outflow obstruction.

Transection of the main pulmonary artery and end-to-side anastomosis of the proximal pulmonary artery to the ascending aorta has been increasingly used in palliative surgery for cardiac malformations such as single ventricle with small outlet foramen (bulboventricular foramen) and hypoplastic left-heart syndrome. To evaluate pulmonary valve competence after this operation, we used color Doppler flow mapping to examine 45 survivors of pulmonary artery-to-ascending aorta anastomosis a median of 202 days postoperatively. Of 37 patients with hypoplastic left heart syndrome, mild regurgitation was detected in 9 (24%) and moderate regurgitation in 1 (3%). Of 8 with other lesions, mild regurgitation was observed in 2 and moderate regurgitation in 1. Seven of 11 patients imaged greater than or equal to 12 months postoperatively had regurgitation. In summary, one-fourth of survivors developed mild pulmonary regurgitation. Its presence should not be considered a contraindication to eventual application of Fontan's principle, although further follow-up appears warranted because the long-term fate of pulmonary valve function is not yet known.

Impact of two-dimensional and Doppler echocardiography on care of children aged two years and younger.

To determine the impact of 2-dimensional (2-D) and Doppler echocardiography on the care of children aged 2 years and younger with suspected cardiac disease, the clinical management and outcome for the years 1975 (pre-2-D/Doppler era, 161 patients) and 1985 (2-D/Doppler era, 206 patients) were compared. Differences were: (1) decreased catheterization at our institution (48% vs 21%, p less than 0.0001); (2) trend toward decreased recatheterization of patients with referral catheterization (62% vs 38%, p = 0.08); (3) increased operation without preoperative catheterization (10% vs 37%, p less than 0.001); and (4) decreased preoperative catheterization for 7 anomalies (patent ductus arteriosus, ventricular septal defect, atrial septal defect, atrioventricular canal, aortic stenosis, tetralogy of Fallot and complete transposition of great arteries). Operative mortality rates were not statistically different in the years compared. Also, the operative mortality rates in 1985 for patients with and without preoperative catheterization were not statistically different. In 1975, cardiac catheterization changed the primary clinical diagnosis in 21%. In 1985, the primary diagnosis was not changed by catheterization; however, 2-D and Doppler echocardiography changed the diagnosis in 18%. The change in utilization of cardiac catheterization appears to be most closely related to the maximal utilization of a substitute imaging and hemodynamic modality--namely, 2-D and Doppler echocardiography.

Definitive operation for pulmonary atresia with intact ventricular septum. Results in twenty patients.

Definitive operation was performed on 20 patients (aged 25 to 178 months) with pulmonary atresia and intact ventricular septum. All patients had one or more prior preliminary palliative procedures. Right ventricular outflow tract reconstruction with atrial septal defect closure and shunt removal was done on 10 patients. Tricuspid annular circumference was at least 70% of normal in seven patients and between 55% and 70% in three patients. Two patients died during hospitalization. The eight surviving patients were asymptomatic 3 to 145 months after operation. The modified Fontan operation was performed on 10 patients. None of these patients had a tricuspid annular circumference greater than 70% of normal; the circumference was less than 55% in nine patients and between 55% and 70% in one patient. One patient died during hospitalization and one died later. Follow-up 6 to 48 months after operation showed that six patients were in the New York Heart Association Class I and two were in Class II. After effective preliminary palliation of pulmonary atresia with intact ventricular septum, definitive operation can be done with an operative risk of 15% (three of 20 patients) and excellent late results. Right ventricular outflow tract reconstruction can be done as a complete repair for patients who have adequate tricuspid annular size. The modified Fontan operation is the only option for definitive repair when the tricuspid anulus is severely hypoplastic.

Cor triatriatum dexter: two-dimensional echocardiographic diagnosis.

Cor triatriatum dexter is a malformation resulting from lack of normal regression of the embryonic right valve of the sinus venosus. In this situation, the right atrium is divided by a membrane into two chambers. Two-dimensional echocardiography was used in the antemortem diagnosis of this rare cardiac anomaly in a neonate. Associated cardiac lesions were also documented. The patient died, and findings were verified at autopsy.

Progressive atrioventricular block during exercise in univentricular heart.

Two patients who had univentricular heart presented with complaints of recurrent nausea and vomiting during exertion. Exercise study revealed 1:1 atrioventricular conduction and no symptoms at rest; at peak exercise, both patients experienced progressive, high grade, second degree atrioventricular block and nausea. Both patients underwent permanent pacemaker implantation, with relief of symptoms. Exercise testing is important in evaluating patients who are at increased risk of spontaneous atrioventricular block, and exertion-induced nausea may be a clue to its presence.

Spectrum of cardiac involvement in Friedreich's ataxia: clinical, electrocardiographic and echocardiographic observations.

Combined 2-dimensional and M-mode echocardiography was used to assess the cardiac status of 22 patients with Friedreich's ataxia, and the findings were correlated with the clinical and electrocardiographic (ECG) data. Mean age at onset of Friedreich's ataxia was 8 years (range 3 to 18); mean age at echocardiography was 18 years (range 8 to 39). Echocardiographic findings were abnormal in 19 patients (86%). The 3 patients with normal echocardiographic findings did not have cardiac symptoms, but 1 had ECG repolarization abnormalities. Concentric left ventricular (LV) thickening, the most common echocardiographic finding, was found in 15 patients (68%) and in all 15 the papillary muscles were thickened. These 15 patients had ECG repolarization abnormalities and 5 had left-axis deviation; however, only 3 satisfied ECG criteria for LV or right ventricular hypertrophy. Two of the 15 patients (9%) had symptoms of heart failure. Two patients had asymmetric septal thickening without clinical evidence of LV outflow tract obstruction; neither had cardiac symptoms, but both had ECG repolarization abnormalities. Two patients showed a dilated cardiomyopathy pattern; both had heart failure and atrial flutter. One of these patients died, and necropsy revealed 4-chamber cardiac dilatation, biventricular hypertrophy and histologic findings of diffuse interstitial fibrosis, myocellular hypertrophy and necrosis. This study revealed a wide spectrum of cardiac abnormalities in patients with Friedreich's ataxia.

Results of the modified Fontan operation for congenital heart lesions in patients without preoperative sinus rhythm.

Preoperative sinus rhythm has been a criterion for the Fontan operation. However, of 297 patients who underwent the Fontan operation between October 1973 and February 1984, 12 (4%) did not have sinus rhythm. The age at operation ranged from 4 to 34 years (median 15). Nine patients had a univentricular heart, two had tricuspid atresia and one had a complex form of transposition. In all 12 patients, 3 to 8 of the 10 proposed criteria for operability were not met. An atrioventricular (AV) conduction abnormality was present in seven patients, six with complete AV block and one with AV dissociation. The patient with complex transposition had complete AV block and atrial fibrillation. Postoperatively, all seven patients continued to have an AV conduction abnormality, and those with complete AV block had a permanent pacemaker implanted. Six of the 12 study patients had atrial flutter or fibrillation refractory to antiarrhythmic medications. Postoperatively, four of the six patients had sinus rhythm. Two of the six patients had complete AV block (including the patient with complex transposition) and both had a permanent pacemaker implanted. Three of the 12 patients died (mortality rate 25%). The nine survivors were followed up for 6 to 55 months; no late deaths occurred. All had marked clinical improvement. This study demonstrates that 1) complete AV block is not a contraindication to the Fontan operation, 2) some patients may not require AV synchrony postoperatively for survival, and 3) postoperative atrial flutter or fibrillation may cease or be easier to control after the Fontan operation.