About 1.5 million children are born each year world-wide with congenital heart disease. The nine most frequently occurring lesions are patency of the arterial duct (ductus arteriosus), atrial septal defect within the oval fossa, atrioventricular septal defect, ventricular septal defect, coarctation of the aorta, valvar pulmonary stenosis, valvar aortic stenosis, tetralogy of Fallot, and complete transposition. Their natural history is presented and compared with representative results of surgical treatment. Surgery has markedly improved the outcome for all these lesions, although almost no patients have been followed postoperatively for more than 25 years. Because congenital heart lesions are likely to consume an increasing proportion of cardiological resources in future years, the long-term future in this field rests with prevention of these lesions if at all possible. Recent advances in molecular and developmental biology, some of which are discussed, will certainly aid in diagnosis and may well bring the time at which prevention can be achieved closer to reality.

The organization of the national health service in the United Kingdom has been under constant review and revision since its inception after the Second World War. Central government spends £35,894 million each year on the Health Service and it is the country's largest employer. Total health expenditure in the United Kingdom accounts for 6.1% of the Gross Domestic Product. This apparently compares unfavorably with 12.4% total health expenditure in the United States.States. However the public health expenditure is identical in the two countries, 5.2%, and this figure is similar in most developed countries including Australia, Denmark, Spain and Switzerland. The overall regional administration of the Health Service in England (Scotland, Wales and Northern Ireland have slightly different organizations) is well established, although the names of the different strata of administration change from time to time. The Secretary of State for Health oversees the Department of Health including the National Health Service Management Executive. Under this Management Executive are 14 Regional Health Authorities covering 100% of the total population.There are within the London area several Special Health Authorities set up in the past because of the particular expertise which they provided. These are under review and will almost certainly lose their special status in the future because of the improvements and increase in services nationwide. The Regional Health Authorities have under their care 177 District Health Authorities and 90 Family Health Service Authorities.They do not manage the National Health Service Trusts—a new development which allows hospitals and other organizations within the Health Service to work autonomously to provide NHS services.

The Constitution of the United States of Mexico, in its Article Number 4, provides for the right to health care. The government's National Health Program was created to comply with this mandate. This program comprises a National Health Care System. This system has three branches. The first one is Social Security, which encompasses 50% of the population of Mexico—namely 45 million affiliates. Out of this popu lation, 10 million are under the “Instituto Mexicano del Seguro Social-Solidaridad.”This program is financed by federal resources, is self-managed by the “Instituto Mexicano del Seguro Social” and provides health care to the general population (basically farmers). The rest of the population that receives benefits from the Social Security System includes employees, blue-collar workers (affiliated with the “Instituto Mexicano del Seguro Social“), federal and state-government workers (who receive benefit from “Instituto de Seguridad Social de los Trabajadores al Servicio del Estado”) and the military personnel (who are affiliated with the “Instituto de Seguridad Social de las Fuerzas Armadas”). These institutes are jointly financed by employers, the state, and the workers.The payment percentage is established depending on the worker's income. For state workers and armed forces it represents 2% of the income of the employee and another 2% is paid by the state; those depending on die Instituto Mexicano del Seguro Social pay 3.5% of their salary and 8.4% is paid by die employer.

A 29-year-old man, with a diagnosis of congenitally corrected transposition (discordant atrioventricular and ventriculoarterial connections) with associated multiple ventricular septal defects, mild pulmonary valvar stenosis and Ebstein's malformation of a stenotic left-sided morphologically tricuspid valve, died after closure of the ventricular septal defect and insertion of a valved homograft conduit between the morphologically left ventricle and the pulmonary trunk. Death occurred because of failure to appreciate the bizarre and rather stenotic anomaly of the morphologically tricuspid valve, in which the anterosuperior leaflet divided the morphologically right ventricle into an inlet portion and a smaller outlet portion. After closure of the ventricular septal defects, this ventricle could no longer support the systemic circulation. We discuss the natural history and the reasons for the erroneous interpretation of the echocardiographic images of the left-sided tricuspid valve.

Over the last 30 years, 94 episodes of infectious endocarditis have been identified in 86 children seen at the Children's Hospital of Pittsburgh. In most of these children no precipitating event could be documented. There was no change in underlying cardiac anomalies over the three decades of this study, and left ventricular outflow tract obstruction, ventricular septal defect and tetralogy of Fallot were the most common anomalies. Streptococci and staphylococci were the most common infecting organisms, and there was a slight increase in the percentage of streptococci in the last decade. Cardiovascular damage occurred in about one-third of the cases, and aortic regurgitation was most common. Mitral regurgitation was also an important complication, as was the development of an aortic aneurysm. Important systemic and pulmonary emboli were rare. Surgical intervention was necessary in one-fifth of the children. Valvar replacement was the most common procedure done. The mortality rate declined markedly over the period of the study, dropping from 36% in the first decade to 8% in the last.

Between February 1980 and February 1992, 28 children (17 males and 11 females) were treated for endocarditis on congenital cardiac lesions, most commonly the mitral valve (32%). Their ages ranged between four months and 14 years (mean 8.2 years). The most common infecting organism (in 25% of patients) was Staphylococcus aureus. Patients were divided into two groups. In the first, made up of eight patients, cardiac surgery was undertaken within one week of the start of antibiotic therapy. The second group of 20 patients was further divided into a group of seven patients who underwent surgery during the initial, active stage of endocarditis because of failure of medical management and a group of 13 patients who initially received antibiotic therapy alone. In this last group, three infections with the same organism recurred within two months and surgical intervention was necessary in the active phase of the recurrence. Subsequently, surgery for “healed” endocarditis was undertaken in three more patients. Mortality in the 21 patients undergoing surgery was 19%—one of eight (12.5%) in those undergoing surgery within one week of starting treatment and two of 10 in the remaining patients. Overall, three patients (15%) died from those in whom surgery was not undertaken within one week of the start of treatment. There were also fewer pre- and postoperative complications as well as a lower mortality rate in those undergoing early surgery. We conclude that early surgical intervention, in our hands, is the most appropriate management for endocarditis in congenital cardiac lesions.

Twenty-six patients requiring palliation for the tetralogy of Fallot were treated by balloon dilation. The mean age at dilation was 8.5 months (range 0.5−20.6) and the mean weight 6.7 kg (range 2.6−10.7). Successful dilation was achieved in 25 patients. The mean ratio of the balloon to the diameter of the pulmonary outflow tract was 1.6 (range 1.2−2.0). The aortic oxygen saturation increased from mean±SD of 80±12.4% before to 91±4.3% after dilation (p<0.05). The pulmonary arterial oxygen saturation rose from 64±10.7% to 80±7.7% (p<0.05). Transient hypotension and arterial desaturation were noted in 19 patients during inflation of the balloon. One patient had a cardiac arrest prior to dilation and died afterwards. Seven patients had cyanotic spells related to the procedure. Attempts to cross the pulmonary valve resulted in infundibular perforation by the guide wire in one patient. Of the 24 survivors who initially had successful dilation procedures, three have needed a Blalock-Taussig shunt. Palliation without a shunt was achieved in the remaining 21 patients. In 12 patients, repeat angiography, 2.5−20 months (mean 9.1) after dilation, showed an increase in the diameter of the outflow tract from 7.1±2.1 mm before to 9.5±2.0 mm after dilation (p<0.05). Diameters of the pulmonary arteries increased from 6.3±2.2 mm on the right and 6.8±1.9 mm on the left before to 9.2±2.2 mm and 9.3±2.5 mm respectively after dilation (p<0.05 for both branches). Surgical correction has been achieved in 22 patients, 21 of these 2−22 months after balloon dilation and the other patient 20 months after construction of a shunt. At operation, the leaflets of the pulmonary valve were noted to be torn in five patients. In 12 patients, there was extensive scarring of the infundibulum. Balloon dilation of the right ventricular outflow tract achieves adequate palliation and may result in an increase in the diameter of the pulmonary valve and branches of the pulmonary trunk. It should be considered as an alternative to shunt procedures in children with tetralogy of Fallot.

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.

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.

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.

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.

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.

A 29-year-old woman who had tetralogy of Fallot and pulmonary atresia with major aortopulmonary collateral arteries developed aortic regurgitation due to infectious endocarditis. Isolated aortic valve replacement was undertaken because of heart failure unresponsive to medical therapy. Excessive flow through the aortopulmonary collateral arteries during cardiopulmonary bypass was controlled by means ofintraaortic balloons which were inflated to occlude the origin of the collateral arteries. Arterial return from the pump was delivered through separate cannulation of the ascending aorta and the right femoral artery. We believe that this method should be considered in those circumstances when excessive flow through systemic-to-pulmonary arteries is expected during cardiopulmonary bypass.

Balloon pulmonary valvoplasty was performed in a patient with congenitally corrected transposition, aged 28 years, who had already undergone surgical closure of a ventricular septal defect and implantation of a conduit between the pulmonary arteries and the right-sided morphologically left ventricle. The patient developed stenosis of the conduit 22 years after the procedure as confirmed by cardiac catheterization and angiocardiography, which also showed stenosis of the native pulmonary valve. A balloon valvoplasty of the native valve was carried out with improvement of the gradient from the ventricle to the pulmonary arteries. The patient developed complete heart block immediately after the procedure, which reverted to first degree block in one week and to the previous cardiac rhythm within 21 days.

A symptomatic neonate was referred for aortic coarctation and, at cineangiography, was shown to have an interruption of the aortic arch at the isthmus together with coarctation related to a persistent fifth aortic arch. Balloon dilation of the coarctation was performed, but the coarctation was still evident after six months. A graft was then interposed between the left subclavian artery and the descending aorta. Balloon dilation was repeated five years later leaving a residual gradient of 11 mm Hg.

A 43-year-old female with complaints of exertional dyspnea was found by Doppler echocardiography to have fixed subaortic stenosis and a redundant mitral valve which, during systole, formed a chamber in the left ventricular outflow tract. This resulted in a subaortic gradient of 40 mm Hg. There was also moderate aortic regurgitation.