Resynchronization pacing is a useful adjunct to the management of acute heart failure after surgery for congenital heart defects.

The acute hemodynamic effect of atrioventricular (AV) and inter/intraventricular (IV) resynchronization accomplished by temporary pacing using multiple epicardial pacing wires was evaluated in 20 children (aged 3.4 months to 14.0 years) after surgery for congenital heart defects fulfilling the following criteria: (1) presence of AV and/or IV conduction delay, and (2) need for inotropic support. AV resynchronization (n = 13) was achieved by AV delay optimization during atrial synchronous right ventricular outflow tract pacing. IV resynchronization (n = 14) was accomplished by atrial synchronous pacing from the right ventricular lateral wall in 7 patients with right bundle branch block and normal AV conduction and by atrial synchronous multisite ventricular pacing in another 7 patients with previously performed AV resynchronization. Compared with baseline values, AV resynchronization resulted in an increase in arterial systolic, mean, and pulse pressures by 7.2 +/- 8.3% (p <0.01), 8.6 +/- 8.1% (p <0.005), and 6.9 +/- 13.5% (p = NS), respectively. IV resynchronization used either alone or added to previously performed AV resynchronization led to a pressure increase of 7.0 +/- 4.7%, 5.9 +/- 4.7%, and 9.4 +/- 7.8%, respectively (p <0.001 for all). The combined effect of AV and IV resynchronization resulted in a systolic, mean, and pulse pressure increase of 10.2 +/- 5.0% (range 4.0 to 19.1), 8.6 +/- 5.4% (range 0.8 to 14.8), and 15.2 +/- 8.5% (range 6.1 to 33.3), respectively (p <0.001 for all). The increase in systolic arterial pressure after IV resynchronization was positively correlated with the initial QRS duration (r = 0.62, p <0.05) and extent of QRS shortening (r = 0.66, p <0.05). In conclusion, resynchronization pacing led to a significant increase in arterial blood pressure and was a useful adjunct to the treatment of acute postoperative heart failure in patients with AV and/or IV conduction delay.

Nitrogen balance, 3-methylhistidine excretion, and plasma amino acid profile in infants after cardiac operations for congenital heart defects: the effect of early nutritional support.

OBJECTIVE: The objective of this study was to evaluate the effect of nutritional support on proteolysis and plasma amino acid profile in infants early after cardiac operations for congenital heart defects. METHODS: Thirty-seven patients, 2 to 12 months old, were randomized on postoperative day 1 for 24-hour isocaloric metabolic study. Group STANDARD (18 patients) received glucose as the maintenance fluid, and group PN (19 patients) received glucose and crystalloid amino acid solution at a dosage of 0.8 +/- 0.1 gm/kg per day. The nonprotein caloric intake in the two groups was 25 +/- 15 and 33 +/- 9 kcal/kg, respectively (p = not significant). RESULTS: The nitrogen balance was markedly less negative in group PN than in group STANDARD (-114 +/- 81 vs -244 +/- 86 mg/kg, respectively, p = 0.001). There was a highly significant inverse correlation between the nitrogen balance and urinary 3-methylhistidine excretion in both groups, but the muscle proteolysis was blunted more effectively in patients receiving amino acids. Concentrations of the plasmatic branched-chain amino acids, alanine, glycine, and proline, decreased significantly in group STANDARD but not in group PN on postoperative day 2. Glutamine and threonine levels declined significantly on postoperative day 2 in both groups. Low levels of arginine were observed in our patients before operation and in the early postoperative period. The amino acid concentrations normalized on postoperative day 7 in all patients. CONCLUSION: Significant proteolysis and hypoaminoacidemia were observed in infants early after cardiac operations. This hypercatabolic response was blunted by parenteral nutritional support.

Correction of aortico-left ventricular tunnel during the first day of life.

Two critically ill newborns with aortico-left ventricular tunnel and severe heart failure were operated on at six and 14 hours after birth. The diagnosis was established clinically by the auscultatory finding of systolic and diastolic murmurs and by two-dimensional and Doppler echocardiography. In the first newborn, the left aortic sinus was connected with the left ventricle below the aortic valve by an aneurysmatically dilated tunnel. In the second patient, the tunnel connected the right aortic sinus and the left ventricle. The repair was performed under deep hypothermia, total hemodilution, and cardiopulmonary bypass. The tunnel was closed with two patches of Gore-Tex on the aortic and ventricular orifices. Both children are free from symptoms and are developing normally 10 and 8 months after repair.

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.

Pulmonary function in children with atrial septal defect before and after heart surgery.

OBJECTIVE: To test the effect of heart disease and heart surgery on lung function. DESIGN: A pulmonary function study of children undergoing surgery for atrial septal defect (ASD). SETTINGS: University hospital. PATIENTS: 26 children tested before surgery (at mean (SD) age 11.8 (3.8) years) and 24 patients tested 1.8 (0.2) years after surgical correction. METHODS: Lung volumes, lung elasticity, and airway patency indices were measured using standard techniques. RESULTS: Before surgery: pulmonary function test abnormalities were found in 18 of the 26 patients. Stiff lung was found in 12, lung hyperinflation in five, and indices of decreased airway patency in four. Total lung capacity decreased in only two patients. After surgery: pulmonary function test abnormalities were found in 12 of the 24 patients (informed consent not given for two patients). Stiff lung was detected in nine and indices of peripheral airway obstruction in four. Mean values of specific airway conductance and peak expiratory flow were all normal. Lung hyperinflation was found only in one of 24 patients. No correlation between perioperative events and pulmonary function test data was found. CONCLUSIONS: Pulmonary function test abnormalities persist in half the patients almost two years after surgery for ASD. A decrease in the total frequency of pulmonary function test abnormalities (in 19% of the patients), with a decrease in stiff lung in 8% and lung hyperinflation in 15%, was not significant. Impairment of lung function related to ASD is associated with the disease itself rather than the surgical procedure.

Lung function in children and adolescents with tetralogy of Fallot after intracardiac repair.

We studied lung function in 41 patients, aged 6-27 years, 1-5 years after intracardiac surgical repair (ICR) of tetralogy of Fallot (TOF) and about 5 years after the establishment of the Pediatric Cardiac Center in Prague. The measurements included vital capacity (VC), total lung capacity (TLC), functional residual capacity (FRC), residual volume (RV), forced expiratory flows (FEF), specific airway conductance (SGaw), lung recoil pressure (Pst), and specific static lung compliance (SC1st). Single or multiple abnormal lung function parameters were found in 83% of patients. Lung function was not related to shunting operations prior to ICR, hemoglobin concentration, and hematocrit, and had no specific pattern. Pst at 100% TLC and 90% TLC declined with increasing age at ICR and at lung function testing, while SC1st rose, as did the ratio FRC/TLC. Fifteen patients were studied before and after surgery. Single or multiple lung function tests were abnormal in 93% before and in 84% after ICR. After ICR the ratios FRC/TLC and also RV/TLC, FEF at 25% VC, and FEF at 60% TLC were less frequently abnormal, while Pst at 100% TLC and at 90% TLC, as well as SGaw and TLC, were more frequently abnormal after ICR. The results indicated a regression of smaller airway obstruction and lung hyperinflation after ICR. The evolution of abnormally compliant (emphysematous) lungs with growth of the patients might be a sign of permanent sequelae of early lung damage from abnormal pulmonary hemodynamics.

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.

Successful reoperation for severe left bronchus compression after repair of persistent truncus arteriosus with interrupted aortic arch.

Signs of the left bronchus compression, caused by aneurysmatic dilatation of the aortic root with severe aortic regurgitation, occurred 5 months after repair of the truncus arteriosus with interrupted aortic arch in an 85-day-old infant. At reoperation the dilated ascending aorta was replaced with a 14-mm Dacron tube. The aortic valve was replaced with an 18-mm Carbomedics valve. Compression of the left bronchus and the right pulmonary artery were released. The right pulmonary artery was enlarged with a pericardial patch and the original homograft was replaced with a new one. The patient remains in good clinical condition 2 years later.

Primary repair of transposition of the great arteries with interrupted aortic arch.

Primary repair of transposition of the great arteries with interrupted aortic arch was performed in a 2 day old neonate weighing 2.1 kg. The repair consisted of a direct anastomosis between the ascending and the descending aorta and an arterial switch repair without Lecompte procedure because of the side by side position of the great arteries and an anomaly of the coronary arteries. A total of 28 months after the repair, the patient remains in excellent clinical condition.

Good exercise tolerance and impaired lung function after atrial repair of transposition.

OBJECTIVE: Evaluation of long-term results of atrial correction of transposition of the great arteries (TGA), focusing on the relationship between pulmonary function and exercise tolerance. METHODS: A prospective population-based study-56 out of 60 survivors of Mustard/Senning repair, born in Bohemia in 1980-1984 (median age at surgery 0.85 years) were followed up over 13.4 +/- 1.2 years and studied by complete lung function and bicycle exercise testing. RESULTS: Maximum heart rate on exercise reached 181 +/- 14 bpm (Z-score: -1.06 +/- 1.66, range -6.7 to +1.6); VO2max: 40.6 +/- 6.7 ml/kg per min (Z-score: -0.97 +/- 1.4, range -5 to +1.8). A total of 73.6% had abnormal lung function, most frequently features of stiff lung (39.6%) and lung restriction (32.1%). Static recoil pressure of the lungs measured at 100, 90 and 60% of total lung capacity reached 137, 126 and 130%, respectively (Z-score: 1.93 +/- 2.33, 1.64 +/- 1.96, and 1.14 +/- 1.95, respectively). There was an inverse relationship between static recoil pressure of the lungs and VO2max (r = -0.306, P = 0.043), indicating the impact of lung function abnormalities on exercise tolerance. Comparison with lung function study of the group of 'pioneer' Mustard patients operated at the mean age of 4.4 years revealed a similar pattern and frequency (73.6% in current series vs. 88%, NS). CONCLUSIONS: Long-term follow-up has shown good exercise tolerance in the majority of patients after atrial correction of TGA performed in infancy. Many of them, however, have impaired lung function, especially stiff lung, although less frequently than original patients operated at a later age. The stiff lung can impair the exercise tolerance.

Operative treatment of infective endocarditis in children.

A retrospective review of 11 children, aged 2 months to 15 years, demonstrates the feasibility of surgical treatment for infective endocarditis in childhood. Except for one case of perinatal infection, in all instances the infective endocarditis was a complication of a congenital heart defect. As medical treatment was not successful, surgery was indicated. Debridement of infected tissue and repair of the congenital heart defect was performed. There were no septic complications postoperatively although 8 patients were operated upon during the active stage of infection. One 2-month-old child did not survive excision of an infected tricuspid valve. The follow-up period of 8 years to 5 months (median 39 months) showed a good haemodynamic result (NYHA class I) in the remaining 10 patients. This included 4 patients with prosthetic valves.

Intermediate to late results of surgical relief of vascular tracheobronchial compression.

Since 1979, a total of 69 infants and children aged 0.1 to 11.9 (median 0.7) years required surgical intervention for: double aortic arch (26), anomalous origin of innominate artery (26), right aortic arch with left ligamentum arteriosum (9), pulmonary artery sling (5), retroesophageal right subclavian artery (3). Before operation, the morbidity was high: 84% of children were symptomatic in the first trimester of life with 24 patients requiring mechanical ventilation. Seven children had an accompanying heart defect. Left thoracotomy was the preferred approach. There were 2 early (asphyxic brain damage, postoperative pneumonia) and 2 late (tracheomalacia, complex heart defect) deaths. Five patients (2 originally operated elsewhere) needed reoperation for persistent symptoms. All 65 survivors are well 1 month to 11.9 (mean 3.9 +/- 3.62) years after surgery. Tracheobronchoscopy, magnetic resonance imaging, and lung function testing were helpful for postoperative evaluation. Minor tracheal compression was revealed in 4 patients despite their good clinical condition.

Minimisation of priming volume and blood saving in paediatric cardiac surgery.

We started a programme of donor blood reduction for open heart surgery in children in 1983. At first, only meticulous surgical and perfusion techniques were used. Later, increased haemodilution was added. Miniaturisation of the perfusion circuit and introduction of blood taken prior from the patient further decreased donor blood requirements. In 1989, we used 0.89 l per patient compared to 3.2 l per patient in 1983. Miniaturisation of the circuit was tested in a pilot study on 30 children undergoing the Senning operation in 1988. Priming volume was reduced from 661 +/- 72 ml to 421 +/- 62 ml. In 1989, 167 out of 194 children (86%) received a clear prime. Ninety-seven of 100 children whose weight was over 15 kg received a clear prime: 55 did not require subsequent transfusion. Prime miniaturisation and autotransfusion can considerably reduce blood requirements for open heart surgery.

Surgical treatment of aortico-left ventricular tunnel.

Thirteen children (age range 6 h-11 years, median 4 months) operated upon for aortico-left ventricular tunnel since 1971 are reported. All patients had systolic and diastolic murmurs, 4 of 5 neonates were in severe congestive heart failure. Twelve children had left ventricular hypertrophy on ECG with an ischaemic pattern in the neonates. Chest X-ray revealed cardiomegaly with a broad upper mediastinal shadow from the enlarged aorta. Echocardiography (2DE) revealed a tubular communication between the aorta and the left ventricle bypassing the aortic valve and massive regurgitation through this tunnel demonstrated by Doppler sonography. In 8 patients, the diagnosis was confirmed by angiography. The tunnel arose from the right coronary sinus in 12 and from the left coronary sinus in 1 patient. The tunnel was closed at both ends in 8, at the aortic end only in 3 and at the ventricular end in the remaining 2 cases. One 6-day-old infant, operated upon in 1971 died postoperatively. There was 1 non-cardiac related late death due to a brain tumour. Echocardiographic analysis of left ventricular size and function was carried out in 9 children up to 39 months after surgery. Mild to moderate aortic incompetence was detected during the follow-up period in 2 of 12 patients. All surviving children are leading normal lives.

Bidirectional Glenn followed by total cavopulmonary connection or primary total cavopulmonary connection?

OBJECTIVE: Analysis of mortality and morbidity of patients treated by primary total cavopulmonary connection (TCPC)-Primary correction group, and comparison to patients treated by bidirectional Glenn (BDG) followed by total cavopulmonary connection-two stage TCPC group. METHODS: Retrospective study of 123 consecutive patients who underwent 144 different types of cavopulmonary connections between 1987-1995: bidirectional Glenn 59, HemiFontan operation 10, primary total cavopulmonary connection 54, and total cavopulmonary connection completion after previous bidirectional Glenn 21. Important preoperative risk factors: age, systemic outflow obstruction, pulmonary venous obstruction, pulmonary artery (PA) hypoplasia (McGoon ratio), PA stenosis/distortion, PA mean pressure, PA vascular resistance, atrioventricular valve regurgitation, systolic and diastolic ventricular function and ventricular hypertrophy were re-evaluated according to Texas Heart Institution Scoring System in both groups. Three different preoperative risk groups were established: low risk, score (0-3) moderate risk (4,5) and high risk score (> or = 6). RESULTS: Mean age was 85.2 month (range 16.1-229.5 months) and 106.6 months (range 42.6-178.9 months) in primary correction group and two stage TCPC group, respectively. Diagnosis was similar in both groups, majority having univentricular heart or hypoplastic one ventricle. Initial palliation (pulmonary artery banding, modified aortopulmonary shunt, coarctation repair etc.) was performed in 38 (70.3%) patients of primary correction group and in 12 (57.1%) two stage TCPC group. The mortality was 7.4% (4 out of 54) and 14.2% (3 out of 21) for primary correction and two stage TCPC group, respectively. There were two take down in the primary correction group. There was no late death in either group. Operative data and postoperative morbidity did not statistically differ in both groups. CONCLUSION: Until 1993 bidirectional Glenn was preferred to primary total cavopulmonary connection for high risk patients. High mortality 14.2% patients of two stage TCPC group vs. 7.4% of primary correction group in patients with the same preoperative hazard led us to change our policy. We now prefer primary TCPC for all patients with functional single ventricle and surgically correctable major associated defects. High risk patients undergo TCPC with fenestration. Patients not suitable for TCPC undergo either HemiFontan operation or some type of initial palliative procedure.

Results of primary and two-stage repair of interrupted aortic arch.

OBJECTIVE: Early results of primary and two-stage repair of interrupted aortic arch have improved. Experience with different surgical approaches should be analysed and compared. METHODS: Forty neonates and infants with interrupted aortic arch underwent primary repair (19 patients) or palliative operation (21 patients). Twenty (50%) patients were followed-up for 5.1+/-4.3 years. All patients were regularly examined with the aim of determining clinical development, presence of residual lesions or complications and need for re-intervention. Aortic arch and the left ventricular outflow tract growth were assessed by echocardiographic examination. Data from hospital and outpatient department records were analysed. RESULTS: The early mortality was 61.9% after palliative operations and 36.8% after the primary repair. Presence of complications (P < 0.001), earlier year of surgery (P < 0.01), bad clinical condition and acidosis (P < 0.05) represented statistically significant risk factors for death in the whole series. In seven (87.5%) out of eight early survivors, after the initial palliative operation, closure of ventricular septal defect and debanding were done, and in three (37.5%) patients, re-operation for aortic arch obstruction was also required. Out of 12 patients, after the primary repair, one required early re-operation for persistent left ventricular outflow tract obstruction and two needed late re-intervention for left bronchus obstruction. In three (25%) patients, after the primary repair, left ventricular outflow tract obstruction with a maximal systolic pressure gradient higher than 30 mmHg developed. At present, all 20 early survivors are alive. Five patients, after palliative operation, are in NYHA class 1, but in three patients, who are in class III or IV, the outcome is influenced by severe complications. All patients after the primary repair are in class I or II. CONCLUSIONS: Our experience confirmed better results after the primary repair of interrupted aortic arch, which was associated with lower mortality, prevalence of severe complications and need for re-intervention. Higher prevalence of subaortic stenosis after primary repair could be explained by patient selection early in our experience. We recommend the primary repair of interrupted aortic arch and associated heart lesions in neonates, however, in unfavourable conditions an individualised surgical approach with initial palliative surgery should be considered.

Demonstration of MyoD1 expression in oncocytic cardiomyopathy: report of two cases and review of the literature.

Oncocytic cardiomyopathy is a rare arrhythmogenic disorder usually associated with female sex, difficult-to-control arrhythmias, or sudden death of infants and children. Morphologically, it is characterized by the presence of oncocytic cells, which are diffusely distributed or form the nodular structures within the myocardium, occasionally involving the valves, with a large number of mitochondria in cytoplasms. We present two cases of oncocytic cardiomyopathy. The first case had a fatal clinical outcome, and the other case was surgically treated. The nuclear expression of skeletal muscle transcription factor MyoD1 was demonstrated in the first case, supporting the theory that oncocytic cardiomyopathy is a conduction system developmental disorder. To confirm this hypothesis, it is necessary to further investigate myogenic transcription factor program in human cardiac conduction system cells.

Protein profiling of human atrial and ventricular musculature: the effect of normoxaemia and hypoxaemia in congenital heart diseases.

Samples of myocardial tissue were obtained during surgical intervention from children operated for different types of congenital heart disease (tetralogy of Fallot, ventricular and atrial septal defect). Sarcoplasmic, contractile and collagenous proteins were isolated by stepwise extraction from the both right ventricular and atrial musculature. It has been found that: a) the concentration of contractile proteins is significantly higher in the ventricles, b) the concentration of collagenous proteins is significantly higher in the atrium, c) the concentration of sarcoplasmic proteins was not different, d) in children with chronic hypoxia the above atrio-ventricular differences persisted. Moreover, the proportion of the soluble collagenous fraction in the atria was significantly increased.

Phospholipid composition of myocardium in children with normoxemic and hypoxemic congenital heart diseases.

Samples of myocardial tissue were obtained during cardiac surgery from children operated for different types of normoxemic and hypoxemic congenital heart diseases. The phospholipid composition was analyzed by thin layer chromatography. The concentration of total phospholipids (PL), phosphatidylcholine and phosphatidylethanolamine (PE) was found lower in atrial tissue of both normoxemic and hypoxemic groups in comparison with the ventricles. When comparing the difference between hypoxemic and normoxemic defects, hypoxemia was found to increase the concentration of total PL, PE and phosphatidylserine in ventricles and total PL and PE in the atria. The increased level of particular phospholipid species may represent adaptive mechanisms to hypoxemia in children with congenital heart diseases.

Individualized repair of the left atrioventricular valve in spectrum of atrioventricular septal defect.

From September 1977 to October 1995, 287 patients with atrioventricular septal defect (AVSD) aged from 2 months of 21 years underwent total repair in Kardiocentrum in prague. In 97 patients complete, in 20 transitional and in 170 patients partial form of AVSD was present. The repair consisted of closure of the defect and individually modified reconstruction of two atrioventricular (AV) orifices. In cases with a common orifice a two-patch technique was used. Fixation of undivided anterior and posterior common leaflets to patches in an appropriate level was essential in combination with complete closure of the cleft. Incomplete closure of the cleft was performed if potentially stenotic morphology was present. Commissuroplasty with pladgeted mattress stitches was done in patients with dilated annulus and commissuroplasty with a single stitch was performed if the annulus was not dilated. The methods were similar in cases with two AV orifices. The AV valve repair was difficult in the presence of severe regurgitation in valves with potentially stenotic morphology. Of the 287 operated patients 26 (9.1%) died during the early postoperative period. Mortality was 19.6% in the complete form and 3.7% in the partial and transitional forms. The mortality depended on morphology of the left atrioventricular valve. Potentially stenotic valvar morphology represented an important risk factor for death and reoperation. It was necessary to reoperate on 18 (6.3%) patients for significant "mitral" valve regurgitation. Reconstruction of a competent left AV valve is the most important step of AVSD repair which must always be modified according to individual morphological and functional abnormalities.