Milan Šamánek

Prevalence, treatment, and outcome of heart disease in live-born children: A prospective analysis of 91,823 live-born children

SummaryAll 91,823 children born in 1980 in Bohemia (population 6.314 million; area 52,478 square kilometers) were examined at least four times during infancy and at the age of three and four years. All children who died were autopsied and those with heart disease were selected. A total of 779 children (8.223/1000 live births) were suspected by provincial pediatric cardiologists of having a heart disease. All of these were examined at the age of four years at our Center of Pediatric Cardiology. At this age heart disease was proved in 613 alive or decreased children (6.676/1000 live births), congenital cardiac malformations in 589 (6.415/1000 live births), and cardiomyopathies in 24. The most frequent congenital heart defects (CHD) were ventricular septal defect (VSD) (31.41%), atrial septal defect (ASD) (11.37%), aortic stenosis (AS) (7.64%), pulmonary stenosis (PS) (7.13%), coarctation of the aorta (CoA) (5.77%), and transposition of the great arteries (TGA) (5.43%), followed by persistent ductus arteriosus (PDA) (4.75%), atrioventricular septal defect (AVSD) and hypoplastic left heart syndrome (HLHS) (4.07% each), tetralogy of Fallot (TF) (3.56%), and pulmonary atresia (PA) (2.38%). A prevalence of less than 0.1/1000 live births was found for the remaining cardiovascular defects.One hundred fifty-nine (25.9%) patients were admitted to our highly specialized center, 116 (19.7%) catheterized and 85 (13.9%) treated surgically, during the first four years of life. A total of 440 (71.8%) patients survived the fourth year of life. The percentage of deaths was 25.6% among those with congenital heart diseases and 71% with cardiomyopathies. The overall mortality rate was 27% in surgically and 26% in medically treated patients.

Prenatal ultrasound screening of congenital heart disease in an unselected national population: a 21-year experience

Objective To determine the prevalence and spectrum of congenital heart disease (CHD) and the impact of a national prenatal ultrasound screening programme on outcome in a well-characterised population. Design and setting A comprehensive registry was created of all paediatric and fetal patients with CHD over a 21-year period (1986–2006) in the Czech Republic. The centralised healthcare system enabled confirmation of prenatal and postnatal findings clinically and by post mortem. Patients and results In the entire cohort of 9475 fetuses referred for detailed cardiac evaluation, 1604 (16.9%) had CHD, of which 501 (31.2%) had additional extracardiac anomalies. In the pregnancies which continued, 59 (8.6%) of 685 fetuses died in utero, and 626 (91.4%) babies were born alive. Prenatal detection rate was highest in double outlet right ventricle (77.3%) and hypoplastic left heart (50.6%). Detection rate increased significantly (p<0.001) for 12/17 lesions comparing 1986–1999 and 2000–2006. In recent years, detection of hypoplastic left heart reached 95.8% while transposition of the great arteries was diagnosed antenatally in only 25.6%. Conclusion The nationwide prenatal ultrasound screening programme enabled detection of major cardiac abnormalities in 1/3 of patients born with any CHD and 80% of those with critical forms. Nevertheless, owing to the severity of lesions and associated extracardiac anomalies, the overall mortality of antenatally diagnosed CHD remains high. These findings are important for the understanding natural history of CHD for the establishing of screening programmes in Europe.

Children with congenital heart disease: Probability of natural survival

SummaryThe age distribution of death in all children with congenital heart disease (CHD), who died in a 27-year period in Central Bohemia (population of 1.2 million), and the data on the incidence of CHD in children born in Bohemia (population of 6.3 million) in 1980 were used to calculate the probability of survival of a child born with CHD. Eighty-six percent of these children survived to the first month of life—mostly those with pulmonary stenosis (PS, 99%), aortic stenosis (AS, 95%), ventricular septal defect (VSD, 92%), and atrioventricular septal defect (AVSD, 91%). Seventy-one percent of patients survived the first year of life—mostly those with PS (97%), AS (91%), atrial septal defect (ASD, 89%), VSD (80%), and persistent ductus arteriosus (PDA, 78%). In total, 67% of CHD patients can be expected to survive childhood. The highest survival rates were found in PS (94%), AS and ASD (84%), VSD and PDA (70–80%), and coarctation of the aorta (COA, 68%). The survival rate for the remaining forms of CHD was less than 50%.The highest mortality rate (10% of all children born with CHD) can be expected in the first postnatal week. The lowest survival in the first week was found among those with hypoplastic left heart (HLHS, 39%), double-outlet right ventricle (DORV, 50%), truncus arteriosus (TrA, 57%), pulmonary atresia (PA, 70%), and transposition of the great arteries (TGA, 83%). In addition, total anomalous pulmonary venous connection (TAPVC) and single ventricle had the highest risk of death in the first year of life.

Long term ventricular performance after intra-atrial correction of transposition: left ventricular filling is the major limitation

Objective To establish the incidence of systolic and diastolic dysfunction of the right and left ventricle in a large cohort of patients after Mustard or Senning operations and to assess changes in the incidence on long term follow up. Design Postoperative case-control study using radionuclide ventriculography. Ejection fractions, peak filling rates, rapid filling periods and fractions, slow filling periods and fractions, and atrial contraction periods and fractions were studied. Setting Tertiary care centre, ambulatory and hospital inpatient care. Patients A convenience sample of 153 patients studied at median age of 6.9 years (median 4.4 years after surgery). In 99 cases another study was available at a median age of 15.3 years (median 13 years after surgery and 8.8 years after the first study). Results Respective incidences of dysfunction in the first and the second study were as follows: ejection fraction–right ventricle 7.8% and 8.1%, left ventricle 7.2% and 10.1%; peak filling rate–right ventricle 0% and 4.2%, left ventricle 14.3% and 29.5% (p < 0.05); rapid filling period– right ventricle 18.3% and 11.6%, left ventricle 30.2% and 30.5%; slow filling period—right ventricle 4.8% and 3.2%; left ventricle 11.9% and 23.2%;atrial contraction period–right ventricle 0.8% and 4.2%, left ventricle 15.1% and 26.3%; rapid filling fraction–right ventricle both 0%, left ventricle 82.5% and 79.0%; slow filling fraction–right ventricle 0.8% and 4.2%, left ventricle 37.3% and 30.5%; atrial contraction fraction–right ventricle both 0%, left ventricle 79.4% and 71.6%. Conclusions The incidence of systolic ventricular dysfunction is 8% (right ventricle) and 10% (left ventricle) 13 years after surgery, without a significant increase over the eight year follow up. Diastolic filling is abnormal in up to 80% of patients and left ventricular peak filling rate deteriorates with time.

Seven-Year Experience of Noninvasive Preoperative Diagnostics in Children with Congenital Heart Defects: Comprehensive Analysis of 2,788 Consecutive Patients

The spectrum of patients operated on without preoperative catheterization and angiography, the accuracy of echocardiographic diagnosis and its impact on the results of surgical treatment were prospectively assessed in 2,788 children consecutively operated for congenital heart defects (CHD) between 1986 and 1992. The overall percentage of surgery based solely on noninvasive preoperative examination increased from 63% in 1986 to 81% in 1990 and decreased to 72% in 1992. There were no differences in the preoperative diagnostic approach between groups of newborn, infants and children. A high percentage of patients with patent ductus arteriosus (96.5%), atrial septal defect (94%), incomplete atrioventricular septal defect (88.6%), ventricular septal defect (86.3%), coarctation of the aorta (80.2%) and total anomalous pulmonary venous connection (79.3%) was referred for surgery without prior invasive examination, while a lower percentage was found in univentricular heart (48.4%), pulmonary atresia (34.6%) and double outlet right ventricle (27.7%). More patients with pulmonary and tricuspid atresia were catheterized before complete repair compared to those who underwent palliative surgery (p < 0.01 and p < 0.0001, respectively). The echocardiographic diagnosis was correct in 96% of patients. Two patients of those with incomplete preoperative diagnosis died early postoperatively, both with missed apical ventricular septal defect. One with tetralogy of Fallot died after reoperation, the other with persistent truncus arteriosus due to sepsis. When the echocardiographic findings are in full agreement with the clinical status, physical examination, ECG and chest X-ray, we recommend cardiac surgery without prior catheterization in many patients with CHD.

Distribution of congenital heart malformations in an autopsied child population

All stillborn and all deceased children were autopsied during a 27-year period in a given territory with some 1,220,000 inhabitants. Of the 3969 stillborn children, 81 (2.1%) had a congenital heart malformation. Out of the 470,188 liveborn children, 13,629 died before the age of 15 years. Autopsy demonstrated a heart malformation in 1008 (0.21%) of these liveborn children. Thus, with 1089 cases found in the combined stillborn and liveborn and later deceased children, congenital heart malformation was found in 6.2% of all autopsied children. This represented 7.4% of the total mortality of liveborn children and 41.4% of all congenital malformation discovered in the deceased children. In total, 2257 congenital heart lesions were identified with a mean of 2.1 lesions per child. The lesions were classified in 37 categories of heart malformation. The most common malformation was ventricular septal defect, followed by hypoplastic left ventricle and complete transposition. The most frequent heart lesion was also ventricular septal defect followed by patency of the arterial duct. The frequency of the different heart malformations in stillborns differed from that in the liveborn children. The ratio of boys and girls in the overall series was 1.28:1, with pronounced differences in sex distribution being observed in some malformations.

Differences between atrial and ventricular protein profiling in children with congenital heart disease

The purpose of the present study was to compare protein profiling of atria and ventricles in children operated for congenital heart disease. Tissue samples were obtained during surgery from patients with normoxemic (ventricular and atrial septal defects) and hypoxemic (tetralogy of Fallot) diseases. Protein fractions were isolated by stepwise extraction from both fight ventricular and atrial musculature. The concentration of total atrial protein in the normoxemic patients exceeded the ventricular value (110±2.1 vs 99.9±4.0mg.g−1 wet weight, respectively); in the hypoxemic group this atrio-ventricular difference disappeared. The concentration of contractile proteins in all cardiac samples was significantly higher in the ventricles as compared with atria, while the concentration of collagenous proteins was significantly higher in the atria (due to a higher amount of the insoluble collagenous fraction). The concentration of sarcoplasmic proteins (containing predominantly enzyme systems for aerobic and anaerobic substrate utilization), however did not differ between ventricles and atria. Furthermore, ventricular contractile fractions obtained from both normoxemic and hypoxemic patients were contaminated with the myosin light chain of atrial origin. Soluble collagenous fractions (containing newly synthesized collagenous proteins, predominantly collagen I and III), derived from all ventricular samples, were contaminated by low molecular weight fragments (mol. weight 29–35 kDa). The proportion of the soluble collagenous fraction was significantly higher in atrial but not in ventricular myocardium of hypoxemic children as compared with the normoxemic group. It seems, therefore, that lower oxygen saturation affects the svnthesis of collagen preferentially in atrial tissue.

Effect of hypoxaemia on enzymes supplying myocardial energy in children with congenital heart disease

The differences in energy metabolism of the myocardium in children with congenital cardiac malformations producing hypoxaemia (arterial oxygen saturation 77 +/- 2%) or normoxaemia (arterial oxygen saturation 94 +/- 2%) were analysed by measuring the activity of the representative energy-supplying enzymes. Right atrial and ventricular tissue samples were obtained during surgical interventions. We demonstrated that myocardial metabolism was significantly influenced by hypoxaemia: the aerobic capacity of the energetic metabolism was reduced both in the atriums and ventricles. Atrial myocardium was more affected: in addition to citrate synthase, the activity of enzymes connected with lactate uptake and carbohydrate catabolism was also significantly decreased. These results demonstrate that the human heart is able to adapt to hypoxaemia by changing its energetic metabolism.

Lung function in atrial septal defect after heart surgery

Lung volume, indices of lung elasticity and airway patency were measured in 74 patients, 9-21 yr old (15.0 +/- 2.5 yr) with atrial septal defect (secundum type) from 2-11 (5.1 +/- 2.5) yr after successful surgical correction. Clinical condition in all patients was classified as excellent. Heart surgery was performed at the age of 4-14.8 (9.9 +/- 3.0) yr. Lung function abnormalities were found in 35 (47.3%) patients. Lung recoil pressure was significantly increased in 24 (32.4%) patients. The mean value of lung recoil pressure at 100% of total lung capacity reached 123 +/- 31% of the predicted value (P < 0.0001). Specific static compliance was within normal limits. Specific airway conductance was significantly reduced in 13 (17.6%) patients. Maximum expiratory flow at 25% of vital capacity was significantly reduced in 4 (5.4%) patients. Static lung volumes did not differ from reference values. Since various abnormalities of lung function tests (most frequently the tests suggested increased lung stiffness and obstruction of larger airways) were revealed in almost half of the studied children and adolescents after successful surgery for atrial septal defect, we propose to carry out lung function tests routinely as another criterion of health conditions in these patients.

Lung function in simple complete transposition after intracardiac repair

Pulmonary function was measured in 35 patients (mean age 11.6 years) with simple complete transposition 4.4 years after intracardiac repair. A disturbance in the lung function (greater than 2 SD from the normal value) was found in 88% of the patients. A marked increase in static recoil pressure (P less than 0.001) was most frequent (in 66%). Static lung compliance was only 75.1% of the predicted values. Values of mean vital and total lung capacity were decreased (P less than 0.01 and 0.001). Residual volume, the ratios of functional residual versus total lung capacity and residual volume versus total capacity were all increased. The signs of decreased patency of the airways were found in only 4 patients. A negative correlation was detected between the indices of lung stiffness and the age of assessment of lung function. A positive correlation was found between the ratios between functional residual and total capacity and pulmonary blood flow. No other correlation between lung function data and pulmonary arterial pressure or flow was proved. Increased lung stiffness, restriction of lung volume and hyperinflation could influence unfavorably the long-term results in successfully treated patients with simple complete transposition.