We describe three children with chronic renal failure who developed mitral obstructive disease over a period when maintained on hemodialysis. The development and progression of the mitral disease was documented by cardiac catheterization in one child and by Doppler echocardiography in the other two children. These three patients had the lowest body weight among the 16 children undergoing chronic dialysis who were examined cardiologically in our hospital. Autopsy in one child who died from heart failure revealed marked thickening of the leaflets and subvalvar apparatus of the mitral valve with severe obliteration of the intercordal spaces. We found no sign of calcification at the mitral annulus nor at the attachments of the leaflets of the aortic valve, and no Ashoff bodies. We attempted percutaneous catheter balloon valvoplasty in one child which permitted successful renal transplantation after failure of an initial transplantation because of severe pulmonary venous congestion. We conclude that mitral obstructive disease could be a complication of long-term hemodialysis for chronic renal failure. Catheter intervention may serve to release the obstruction, although the procedure is not curative.

We examined 25 heart specimens with aortopulmonary windows in order to review the variety of the lesion and its associated malformations. Unlike common arterial trunk, the aortopulmonary window involves a deficiency of the wall of the ascending aorta and that of the pulmonary trunk. The window was in proximal position in three specimens, intermediate position in three specimens, distal position in 16 specimens and was confluent in three specimens. The size of the window varied from 27 to 100% of the total length of the pulmonary trunk but size did not bear any apparent relationship to the position of the defect. The shape of the window was tunnel-like in one case. Of the 16 specimens with distal windows, the orifice of the right pulmonary artery arose from the aorta in seven specimens and was overriding the plane of the window in one specimen. The window occurred as an isolated lesion in four specimens. It was associated with interruption of the aortic arch at the isthmus in eight specimens and between the left carotid and left subclavian arteries in three specimens. A further three specimens had isthmal stenosis. Among the other associated defects were complete transposition (two specimens), tetralogy of Fallot (one specimen), and double outlet right ventricle (one specimen). A ventricular septal defect was present in six of the 25 specimens. The associated lesions found with aortopulmonary window are seldom encountered with common arterial trunk, suggesting these two arterial lesions have different pathogenesis and are not variants of the same entity.

We have investigated angiographically and histologically the vascular response to implantation of intravascular stents in normal puppies. Eight balloon-expandable stents were placed in six mongrel puppies (weight 6.4–10.5 kg) under anesthesia. Four stents were successfully placed in the pulmonary arteries and three in the aorta. In one case, the strut of the stent was hooked by a leaflet of the tricuspid valve at the time of placement and eventually had to be implanted in the inferior caval vein. Two puppies died, one from bleeding from the femoral artery and the other from thrombotic obstruction at the superior mesenteric artery, both after successful implantation. The former was due to repeat arterial puncture and the latter wasdue to failure to use aspirin. Angiographic studies showed satisfactory opacities of the branch arteries in all but one puppy. The diameter of the arteries prior to implantation was 7.5±1.5 mm. The diameters at the middle of the stents immediately after implantation and during the period of follow-up were 6.9±1.7mm and 6.9±2.1 mm, respectively. Histologic studies revealed that neogenic endothelial layers of 30 to 40 pm in thickness had formed over the struts of the stent without formation of thrombusthree weeks after implantation. Scanning electron microscopy revealed that the endothelial cells of the neoendothelial layer had almost identical characteristics to those of normal arteries. These results indicate that clinical application of this stent is feasible but that use of anticoagulants is mandatory during and after implantation in the treatment of selected patients with aortic coarctation or pulmonary arterial stenosis. Relative progression of stenosis may occur, however, and the inability for re-expansion is a major disadvantage of this stent.

The role of transesophageal echocardiography in the diagnosis and management of left-sided cardiac valvar disease in children and young adults was assessed in terms of whether additional information (over transthoracic echocardiography) could be obtained, and whether the added information contributed to the better management of the patients. Between January 1991 to August 1992, 27 consecutive patients were studied. Their age ranged from 2.5 to20 years (mean 12.7), with body weights ranging between 12 and 60 kg (mean 35.6). Twelve of the children suffered from atrioventricular valvar disease, 13 had predominant aortic valvar lesions and two had mixed valvar pathologies. Additional information was obtained by transesophageal over that of transthoracic echocardiography in 18 children (67%). Transesophageal echocardiography clarified the etiologies or mechanism of valvar regurgitation in eight and seven children with atrioventricular and aortic pathologies, respectively. The technique correctly diagnosed severe mitral regurgitation underestimated by conventional technique, detected a missed eccentric aortic regurgitant jet and convincingly excluded bacterial vegetations in one case each. The investigation contributed to the better management of three children (11%) by providing information that allowed the appropriate choice of therapy. Transesophageal echocardiography, therefore, is a useful technique for the diagnosis and management of valvar disease of the left heart in children and young adults.

Four 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.

Transesophageal echocardiography and magnetic resonance imaging have proved useful as noninvasive imaging modalities in postoperative patients with congenital heart disease, or patients with suboptimal transthoracic echocardiograms. Each modality has specific advantages. When both are of equal efficacy, magnetic resonance imaging is recommended because it is less invasive and more comfortable for the patient.

Between January 1989 and March 1993, total correction was performed in 99 patients with tetralogy of Fallot without submitting them to prior cardiac catheterization. The age of the patients ranged from 1.33 to 18 years (mean 5.33±3.77). After complete echocardiographic examination, the diameters of the right and left pulmonary arteries at the prebranching point and the descending thoracic aorta at the diaphragm were measured by cross-sectional echocardiography and the McGoon ratio was calculated. Total correction was performed in all patients with a McGoon ratio greater than 1.7. In none of the patients were the sizes of the pulmonary artery measured by echocardiography smaller than the measurements obtained during surgery. Transannular patching was performed in 76 patients. A conduit from the right ventricle to the pulmonary arteries was constructed in two patients with coronary arterial anomalies. Postrepair right ventricular to left ventricular systolic pressure ratios were between 0.25 and 0.85 (mean 0.54±0.13). There were two hospital deaths, neither being related to the diagnostic method used nor the criteria for surgery. We conclude that the diagnosis of tetralogy of Fallot together with measurements of pulmonary arteries and descending thoracic aorta can safely and reliably be achieved echocardiographically. The McGoon ratio can be adapted to echocardiography and total correction can be performed successfully based on echocardiographic examination.

Cardiac and extracardiac anomalies tend to follow characteristic patterns when there is an isomeric arrangement of the heart and lungs. We present a case diagnosed correctly during prenatal life as having isomerism of the left atrial appendages in which some of the associated features were most unexpected, namely absence of the spleen and obstructed totally anomalous pulmonary venous connection. This association proved misleading for us in the management of the patient. We found it difficult to believe our findings in the light of our past knowledge, and this resulted in a delay in the referral for surgery. The final outcome was unfortunately fatal. In the management of isomerism of any type, therefore, a wide spectrum of combinations and “crossover” of cardiac anomalies must be anticipated, emphasizing the need to assess individually the arrangement of the different organs of the body.

Digitized M-mode echocardiograms of left ventricular function were obtained in 34 patients subsequent to surgical repair of tetralogy of Fallot and in 34 healthy subjects at rest. In 16 patients and 16 controls, studies were also made during submaximal semisupine bicycle exercise. At rest, the peak ejection rate and fractional shortening were slightly reduced in the patients, whereas peak filling rate was comparable in patients and controls. Pulmonary regurgitation did not seem to influence left ventricular function. During exercise, however, peak filling rate was reduced in the patients compared to the healthy subjects. At peak exercise, the peak filling rates were 27.8±6.3 cm•s−1 and 34.1±3.4 cm•s−1 in patients and controls, respectively (p<0.01). No differences were found in heart rate, fractional shortening, peak ejection rate or blood pressures between patients and controls throughout the exercise test. When the subjects were subdivided by median age, the oldest patients had reduced normalized peak filling rates throughout the exercise test, whereas no differences were found between younger and older healthy subjects. Thus, it is suggested that the reduced left ventricular peak filling rate found during exercise is caused by subclinical myocardial dysfunction which seems to be related to myocardial protection at surgery and the period of follow-up.

Absent right atrioventricular connection, with the left atrium connected to a dominant left-sided morphologically right ventricle, is a rare situation. We report four cases, demonstrating the anatomical correlations and the clinical aspects needed to make the diagnosis. We also discuss the nomenclature of this important combination.

Abstract Lung biopsies were taken at surgery from five patients (age 2–13, average 7.6 years) with tetralogy of Fallot and pulmonary atresia with major aortopulmonary collateral arteries. The biopsies were then processed for ultrastructural study, comparing paired samples taken, on the one hand, from a segment connected to central pulmonary arteries and, on the other hand, from a segment supplied directly by collateral arteries. Specimens from patients with isolated ventricular septal defect, and from those without cardiac disease, were used as controls. In the patients with tetralogy of Fallot and pulmonary atresia, all biopsies taken from segments supplied by the major collateral arteries showed marked deposition of collagen in the alveolar wall, with an increase in the thickness of the basement membrane (3.6±1.2 µm, mean±SD) greater than seen in those taken from segments connected to central pulmonary arteries (0.9±0.6, p<0.05). The proportional fibrosis of the alveolar interstitial space was also significantly greater in the biopsies from the segments supplied by collateral arteries (30±9%) compared to those from segments fed by central pulmonary arteries (15±8%, p<0.05). No significant differences were found in these indices between the biopsies from segments connected to the central pulmonary arteries in patients with tetralogy of Fallot and pulmonary atresia and those from patients with isolated ventricular septal defect or normal controls. There was no apparent relation to the pulmonary arterial pressure in these findings. The results suggest that the pulmonary segments fed directly by major aortopulmonary collateral arteries in patients with tetralogy of Fallot and pulmonary atresia seem likely to be afflicted by alveolar wall fibrosis, although the etiology and clinical implications of this finding remain unclear.

We discuss the management of 10 children with cardiac masses produced bytumors, thrombus or vegetations. The ages of the patients ranged from five days to nine years, only two being more than five years old. In all cases, the diagnosis was made by cross-sectional and Doppler echocardiography. Themasses were detected in the chambers of the right heart in five patients, in the left heart in four and on both sides in one patient. Five patients had predisposing factors. The clinical features were variable, but cardiac failure was the most common sign. All the patients underwent emergency surgery. Two patients died during the period of hospitalization and two in the late postoperative period. The six surviving patients are now asymptomatic.

Syncope has never been described as the presenting symptom of divided left atrium (cor triatriatum sinistrum). We have now encountered this mode of presentation in an otherwise asymptomatic patient. An upright tilt test elicited syncope prior to surgical correction, but failed to induce any symptom, even subsequent to infusion of isoproterenol, after surgery.

Coarctations of the aortic arch are rare, and when found, they are often associated with other complex congenital heart disease. An adolescent female with multiple coarctations of the aortic arch and ventricular septal defects underwent complete repair, entailing replacement of the aortic arch with a homograft and closure of the ventricular septal defects. The postoperative course was complicated by a tear in the homograft, possibly related to sepsis. After its resolution, her hemodynamic results remain excellent.

Between June 1985 and June 1991, 63 children underwent surgical reconstruction of the mitral valve for rheumatic (46 cases), congenital (12 cases) and myxoid (five cases) disease. The ages ranged from two to 18 years (mean 14.1±3.7 years). Valvar dysfunction was classified according to its pathophysiological abnormalities. A group of four cases presented with regurgitation secondary to lesions located in the valvar structures but with normal motion of the leaflets. In a second group of 14 cases, mitral regurgitation was due to prolapsed leaflets because of lesions located mainly in the subvalvar structures. A third group was formed by 35 patients with mitral regurgitation with restricted motion of the leaflets due to lesions in the valvar and subvalvar structures. The final group, of 10 cases, presented with mitral stenosis. The overall surgical mortality rate was 4.7% (3/63), and follow-up data were available in all survivors from one to 96 months (mean 33.4±25.4). Four cases underwent reoperation due to residual incompetence, one case due to bacterial endocarditis, and two more are scheduled for replacement of the valve due to unfavorable evolution, giving an overall rate of reoperation of 4.3% per patient/year. One patient died in the period following valvar replacement (late mortality rate of 0.6% per patient/year). Thromboembolism occurred in four cases in the absence of anticoagulation; three of them were in atrial fibrillation (late thromboembolic rate 2.4% per patient/year). Prior to surgery, 28 cases were in functional class II of the New York Heart Association, 34 patients were in class III and one patient in class IV. At the end of the follow-up period, 49 patients were in class I, seven in class II and four in functional class III (p<0.0001). The cardiothoracic ratio before surgery ranged from 0.40 to 0.81 (mean 0.60±0.07) and, after surgery, the values ranged from 0.40 to 0.79 (mean 0.55±0.07) (p<0.0001). Randomized late echocardiographic evaluation in 24 cases revealed residual mild mitral regurgitation in 20 cases, moderate in two and severe in two. The latter are scheduled for valvar replacement. There were no significant differences in the surgical results among the four groups. Reconstruction of the mitral valve, therefore, provides stable functional results with low surgical and late mortality, as well as an acceptable rate of reoperation irrespective of the lesions of the valvar apparatus.

Three patients aged five years, five years four months and 14 years with obstruction of the systemic venous baffle following the Mustard operation were treated with balloon dilation and implantation ofstents. Balloon dilation of the baffle obstruction was performed initially in the first two cases. In the third case, the obstruction was complete and was punctured with atranseptal needle via a 6 French transeptal sheath followed by a balloon dilation. in all three patients, a Palmaz stent (Johnson & Johnson, Summerville, New Jersey, USA) was loaded onto the balloon catheter and delivered into the stenotic area. There was complete relief of obstruction in allcases. The first case developed supraventricular tachycardia at the time ofcatheterization, the morning following implantation of the stent and thentwo weeks after that. There were no complications with catheterization and noshort-term side effects in the other cases. These cases illustrate the use of endovascular stents in the treatment of baffle obstruction.

A heart is described in which there was a solitary arterial trunk that exited from the heart astride a large perimembranous ventricular septal defect, with the pulmonary arterial supply originating entirely from collaterals from the descending aorta. There was no evidence of either hilar pulmonary arteries or an atretic pulmonary trunk. The morphology of the ventricular outlet component, with absence of the outlet septum supports the description of this heart as solitary arterial trunk, rather than tetralogy of Fallot with pulmonary atresia.

We describe an infant with complex congenital heart disease, including double orifice of the mitral valve associated with complex subaortic stenosis. Transthoracic and intraoperative transesophageal echocardiography were used to define three distinct anatomic abnormalities, all potentially contributing to the subaortic obstruction. Stepwise surgical repair with transesophageal echocardiographic monitoring of hemodynamic function ensured optimal initial surgical results. Overwhelming postoperative complications ensued, however, and the patient died. Postmortem findings are also presented.

So as to understand better the pathogenesis of enlargement or hypoplasia of pulmonary arteries in congenital heart disease, we studied the dimensions of the pulmonary arteries in 74 fetuses with congenital heart disease induced by administration of bis-diamine to pregnant rats. The congenital malformations induced included 12 with large ventricular septal defect, 17 with tetralogy of Fallot, 15 with tetralogy together with severe valvar pulmonary stenosis and absence of the arterial duct, 17 with tetralogy with absent pulmonary valve syndrome and absence of the arterial duct, and 13 with common arterial trunk with a confluent segment supplying the pulmonary arteries. For comparison, 16 fetuses of the same gestational age with normal hearts were studied. After rapid whole-body freezing on the 21st day of gestation, the fetuses were studied by means of serial cross-sectional photographs of the thorax. The diameter of the right pulmonary artery of the fetus was of comparable dimensions in the normal hearts (480±10 µm) (mean±SEM), those with ventricular septal defects (470±10 µm), common arterial trunk (520±20 µm), and tetralogy of Fallot (500±10 µm). These findings suggest that the commonly observed enlargement of the right pulmonary artery in patients with ventricular septal defect and common arterial trunk, and hypoplasia of the right pulmonary artery in tetralogy of Fallot, occur postnatally in response to abnormal postnatal pulmonary blood flow.