Coronary Blood Flow Assessed by Transthoracic Echocardiography in Neonates

Coronary flow measurement has provided useful clinical and physiologic information. However, there is little information about values for coronary flow in normal neonates, much less neonates with congenital heart disease. The aim of this study was to assess coronary blood flow in normal neonates and to compare the results with those in infants with ventricular septal defect. The study groups consisted of 12 normal neonates and 9 infants with simple ventricular septal defect associated with pulmonary hypertension. Left ventricular dimension, left ventricular mass, and the diameter of the coronary vessel were measured by standard M-mode and two-dimensional echocardiography. Peak flow velocities, flow velocity integrals, and flow volumes in the left anterior descending and circumflex coronary arteries were measured. The flow signals from the left anterior descending and circumflex coronary arteries were recorded in 84% (10/12) and 17% (2/12), respectively, in the normal neonates and 78% (7/9) and 11% (1/9), respectively, in the patients. The left ventricular end diastolic diameter and mass were significantly lower in normal infants than in the infants with ventricular septal defect (1.56 ± 0.11 vs 1.84 ± 0.09 cm and 5.4 ± 1.6 vs 8.8 ± 0.8 g, respectively, p < 0.01). The mean peak diastolic velocity and the flow velocity time integral in the left anterior descending coronary artery were significantly lower in the normal neonates than in the patients (15 ± 4 vs 28 ± 6 cm/sec and 2.3 ± 0.6 vs 5.9 ± 1.5 cm, respectively, p < 0.01). The coronary flow volume was significantly lower in the normal neonates than in the patients (3.1 ± 1.4 vs 7.9 ± 4.7 ml/min, p < 0.05). However, the flow volume of the left anterior descending coronary artery/left ventricular mass did not show any significant difference between the two groups. Our study demonstrated in neonates that it is feasible to detect noninvasively and to evaluate the flow of the left anterior descending coronary artery under physiologic conditions and abnormal hemodynamic situations. Increased flow volume in the left anterior descending coronary artery in patients with ventricular septal defect may be a compensated mechanism for the increase in oxygen demand of hypertrophic myocardium of the left ventricle.     

Transient Hypertrophic Cardiomyopathy in Neonates After Acute Fetal Distress

We report three cases of transient myocardial hypertrophy, diagnosed by echocardiography, occurring between the second and seventh days of life in neonates with initially normal ventricular myocardial wall thickness. The three term neonates had perinatal injury with acute fetal distress. In all three cases electrocardiographic and biologic signs of myocardial ischemia were present. The first echocardiographic results showed abnormalities in systolic or diastolic left ventricular function, without hypertrophy of the walls. The hypertrophic cardiomyopathy (HCM) occurred between days 2 and 7 and affected first the interventricular septum and the free wall of the right ventricle. The left ventricular posterior wall subsequently became abnormal, resulting in severe overall myocardial hypertrophy, which finally disappeared in all three cases between 1 and 5 months of life. Such observations of early severe and transient HCM have not been previously reported. We believe it is a consequence of myocardial ischemia due to acute fetal distress. The prognosis of this type of HCM is good, in contrast to that of other primitive HCM occurring in neonates.     

Course of Right and Left Ventricular Function in Patients with Pulmonary Insufficiency After Repair of Tetralogy of Fallot

Surgical repair of tetralogy of Fallot (TOF) frequently results in pulmonary valve insufficiency. Nevertheless, no serial information is available on the long-term impact of the valvular insufficiency on right and left ventricular function. Right and left ventricular ejection fraction was measured serially by radionuclide angiocardiography in 21 patients with at least moderate pulmonary insufficiency after repair of TOF. A baseline study was obtained an average of 1.2 years after repair, and a follow-up study was performed an average of 10.2 years after surgery. Changes in ventricular function over time and deviations from the normal range were analyzed. At baseline evaluation the mean right ventricular ejection fraction (RVEF; 0.52 ± 0.10) and left ventricular ejection fraction (LVEF; 0.68 ± 0.10) were normal. At the time of follow-up the mean RVEF had significantly decreased to 0.45 ± 0.09 (p < 0.01). The mean LVEF had decreased to 0.60 ± 0.11 (p < 0.02). This change was independent of the RVEF (r=−0.13). Eleven patients (52%) had an abnormal RVEF or LVEF at follow-up. Nineteen patients (90%) showed a decrease of 0.05 or more in RVEF, LVEF, or both between studies. These data suggest a negative impact of long-standing pulmonary insufficiency on right and left ventricular systolic function after repair of TOF. Therefore, continued surveillance of biventricular function in this patient population appears warranted.     

Coarctation of the Left Pulmonary Artery: Effects on the Pulmonary Vasculature of Infants

At autopsy, two infants had unsuspected coarctation of the left pulmonary artery (CoLPA), which was produced by an extension of ductal tissue into the wall of the left pulmonary artery. The first case, a 4-month-old girl, also had a ventricular septal defect and an anomalous branching pattern of the innominate arterial trunk. Pulmonary arterial hypertensive changes were noted in the right lung. In contrast, the left lung showed thin-walled pulmonary arteries. The second case, a term female newborn, had exhibited severe unexplained respiratory distress since birth. Histologic sections of the right lung showed dilated pulmonary arteries with thinned media, whereas the left lung showed a persistent fetal arterial pattern. It is believed that the peripheral pulmonary arterial changes are age-dependent and associated with asymmetric blood flow between the right and left pulmonary arteries. CoLPA is a rare pulmonary artery defect, and early diagnosis of this abnormality is important.     

Branch Pulmonary Artery Growth After Blalock–Taussig Shunts in Tetralogy of Fallot and Pulmonary Atresia with Ventricular Septal Defect: A Retrospective, Echocardiographic Study

We performed a retrospective echocardiographic study in tetralogy of Fallot (TOF) or pulmonay atresia with ventricular septal defect (PA&VSD) to evaluate the effects of Blalock–Taussig shunt on branch pulmonary artery growth. There were 35 patients with TOF and 11 with PA&VSD. We measured the right and left pulmonary artery area index and also the combined pulmonary artery area index, both before and after shunt operation. The mean ± SD of these three variables before the shunt operation in the TOF group were 63.5 ± 22.5, 57.8 ± 24.9, and 121.4 ± 42.8 mm²/m²; after shunt operation they were 98.5 ± 33.6, 85.9 ± 31.9, and 184.0 ± 59.8 mm²/m², respectively (p values <0.0001, <0.0002, and <0.0001, respectively). In the PA&VSD group the comparable values before shunt operation were 66.5 ± 16.0, 55.4 ± 10.6, and 120.9 ± 26.9 mm²/m² and after shunt operation were 90.5 ± 22.9, 77.2 ± 24.1, and 166.6 ± 44.4 mm²/m², respectively (p values <0.0006, <0.014, and <0.002, respectively). We also examined the effect of distensibility of pulmonary arteries by comparing the percentage change in size of the combined pulmonary artery area index in the first 4 months after shunt with those after this time (p < 0.023). There were no significant differences between left- and right-sided shunts, origin and distal pulmonary artery growth, and the TOF and PA&VSD groups.     

Resolution of Neonatal Hypertrophic Cardiomyopathy in an Infant with an Affected Mother

Hypertrophic cardiomyopathy (HCM) in infancy has been described in association with many medical disorders. The genetic location and mode of transmission of HCM in families also has been reported extensively. We present an infant with nonobstructive hypertrophic cardiomyopathy whose mother also had HCM. Regression of septal hypertrophy was documented in this patient by 1 year of age despite a positive family history.     

Utility of Intraoperative Transesophageal Echocardiography in the Assessment of Residual Cardiac Defects

To investigate the accuracy of immediate postbypass transesophageal echocardiography in the assessment of residual cardiac defects, we compared intraoperative transesophageal echocardiograms with intra/postoperative data in 86 patients, aged 4 days to 30.7 years (median = 1.4 years), at risk for a total of 174 postoperative lesions: right (n= 55) or left (n= 26) ventricular outflow tract obstruction, ventricular septal defect (n= 65), aortic (n= 12) or mitral regurgitation (n= 8), or mitral stenosis (n= 8). Accuracy of intraoperative transesophageal echocardiography was evaluated based on comparison with (1) immediate post-bypass left (n= 4) or right (n= 9) ventricular outflow tract pressure gradients by pullback in the operating room, (2) direct surgical inspection of residual ventricular septal defects (n= 3), (3) pulmonary artery oxygen saturation (n= 49), (4) right ventricular outflow tract pullback gradient (n= 24), and (5) transthoracic echocardiogram (n= 51) performed within 40 days of surgery. The results indicate that intraoperative transesophageal echocardiography agreed with intra/postoperative data in 87% of patients at risk for right ventricular outflow tract obstruction, 96% at risk for left ventricular outflow tract obstruction, 97% at risk for ventricular septal defect, and 100% at risk for aortic regurgitation, mitral regurgitation, or mitral stenosis. Significant residual lesions led to immediate surgical revision in 11 cases: 3 ventricular septal defects, 6 right and 2 left ventricular outflow tract obstructions. Of these, intraoperative transesophageal echocardiography confirmed and quantified suspected residual lesions in 7 and identified unsuspected lesions in 4 cases. Immediate postbypass transesophageal echocardiography proved reliable for assessing residual ventricular septal defect, mitral stenosis, and mitral or aortic regurgitation. Although accurate for assessment of the left and right ventricular outflow tracts in most patients, transesophageal echocardiography may not reliably reflect the severity of obstruction in all cases.     

Percutaneous Transluminal Angioplasty for Stenosis of the Aorta Due to Aortic Arteritis in Children

Percutaneous transluminal balloon angioplasty for stenosis of the aorta due to aortic arteritis was attempted on 45 lesions in 41 children (age range, 4–14 years; mean, 9.9±4.2 years) presenting with symptoms of hypertension, severe congestive heart failure, and lower limb claudication. Balloon dilatation was technically successful in 38 (92.7%) patients for 41 stenotic lesions (91.1%). The mean peak systolic pressure gradient (PSG) decreased from 71.7 ± 23.9 mmHg to 23.2 ± 17.5 mmHg (p < 0.001) and the diameter of the stenosed segment increased from 3.3 ± 1.1 mm to 7.5 ± 2.2 mm (p < 0.001) immediately after angioplasty. Patients with short-segment (<3 cm) stenosis had a lower residual gradient (17.9 ± 11.1 mmHg vs 30.5 ± 22.6 mmHg; p < 0.05) and a wider diameter of the aorta (8.8 ± 1.1 mm vs 7.5 ± 2.2 mm; p < 0.02) compared to patients with long-segment (≥3 cm) stenosis. Four patients required stent implantation; 2 for flow-limiting dissection, 1 for failure to reduce PSG by >50%, and 1 for recurrent restenosis. There was marked hemodynamic and angiographic improvement in these 4 patients. Hemodynamic and angiographic restudy in 21 of the 41 patients at mean follow-up period of 6.2 ± 4.2 months (range, 3–24 months) showed restenosis in 4 (19%) patients. Restenosis was more common in patients with long-segment stenosis than those with short-segment stenosis (30% vs 9.1%). Late restudy in 8 patients, done at 3–7 years after first restudy, showed no recurrence of aortic narrowing. On clinical follow-up of 38 patients for a mean of 58.8 ± 36.0 months (range, 8–146 months) there was marked improvement in symptoms. Hypertension was cured in 11 (29%), improved in 24 (63%), and persisted in 3 (8%). Six patients with associated severe renal artery stenosis showed further improvement in hypertension after successful renal angioplasty. Severe congestive heart failure improved in 21 (95.4%) of 22 patients. Mean left ventricular ejection fraction improved from 0.32 ± 0.08 to 0.48 ± 0.10 (p < 0.001) at a mean follow-up of 28.7 ± 8.4 months in these patients. Hemodynamic restudy in 10 of these patients showed improvements in left ventricular end-diastolic pressure from a mean 37 ± 9 mmHg (range, 25–55 mmHg) to 16.4 ± 6.2 mmHg (range, 6–25 mmHg) (p < 0.001). Lower limb claudication improved in all 4 patients. Our results suggest that percutaneous transluminal balloon angioplasty in children is safe and highly effective in relieving stenosis of the aorta due to aortic arteritis, with marked clinical improvement, and should be the treatment of choice particularly for discrete stenosis.     

The Relation Between Right Ventricular Function and Left Ventricular Morphology in Hypoplastic Left Heart Syndrome: Angiographic and Pathological Studies

Cases of hypoplastic left heart syndrome (HLHS) were studied angiographically in 18 patients and pathologically in 22 patients. They were divided into three subgroups according to the morphological features of the left heart: mitral atresia with aortic atresia (MA/AA), mitral stenosis with aortic atresia (MS/AA) and mitral stenosis with severe aortic stenosis (MS/AS). Patients with MS/AA had a significantly lower right ventricular end-diastolic volume index and more hypokinesis of the right ventricular posterior wall than those with MA/AA. MS/AA not only increased the thickness of the left ventricular posterior wall and interventricular septum but also increased endocardial thickness compared with MA/AA. Myocardial histology revealed more frequent abnormal findings such as myocardial necrosis, calcification and interstitial fibrosis in the mitral stenosis groups (i.e., MS/AA and MS/AS) than in MA/AA. Right ventricular function appeared to be greatly influenced by left heart structure. The presence of larger left ventricular muscle bulk and frequent myocardial damage seen in MS/AA seems disadvantageous to right ventricular end-diastolic volume and right ventricular wall motion.     

Generation of Reactive O2 Species in the Myocardium of Newborn Lambs Following Intrauterine Increase in Right Ventricular Pressure

Fetuses with pulmonary stenosis and constriction of the ductus arteriosus or the recipient twin in the context of a twin-to-twin transfusion syndrome may present with severe right ventricular myocardial dysfunction. Free O₂ radicals are known to be increased in hypertrophied adult myocardium secondary to an increase in endocavitary pressure. This study investigates whether products of reactive O₂ species generation are abnormally elevated in the myocardium of fetuses with increased right ventricular pressure. Banding of the main pulmonary artery was performed in five fetal lambs at 90 to 100 days of gestation. Three other animals had a sham intervention and were used as controls. Postoperative observation lasted on average 42 days (range 33–49 days). The levels of hydroperoxides were found to be significantly higher in the right ventricle of the stenosed lambs (6.6 ± 3.5 nmol/mg protein) compared to the left ventricle of the same lambs (0.7 ± 0.7 nmol/mg protein), and compared to the right (0.12 ± 0.1 nmol/mg protein) and the left (0.5 ± 0.8 nmol/mg protein) ventricles of the controls. It is concluded that during fetal life, an increase in right ventricular pressure is associated with a marked accumulation of products of reactive O₂ species generation in the right ventricular myocardium.     

Quantitation of the Global Right Ventricular Function in Children with Normal Heart and Congenital Heart Disease: A Right Ventricular Myocardial Performance Index

Although the assessment of right ventricular (RV) function is important in the clinical management of children with congenital heart disease, available imaging techniques have been limited because of the complex geometry of the right ventricle. A new Doppler index combining systolic and diastolic time intervals (the Tei index) has been reported to be useful for the assessment of global RV function in adults. However, normal values in children, age-related changes, and the clinical utility of the Tei index with regard to congenital heart disease have not been demonstrated. The purpose of this study was to prospectively assess RV function in children with normal heart and congenital heart disease using the Tei index. The subjects included 150 healthy children and 43 patients with congenital heart disease (35 patients with atrial septal defects and 8 patients who had had a Senning operation). The index was defined as the sum of isovolumetric contraction time and isovolumetric relaxation time divided by ejection time and was measured from conventional RV outflow and inflow Doppler velocity profiles. The Tei index was not affected by age in healthy children (0.24 ± 0.04). There was a significant difference in index rating between patients who had had a Senning operation (0.58 ± 0.09) and healthy children (p < 0.01), but there was no significant difference between children with atrial septal defect (0.25 ± 0.13) and healthy children. The Tei index is a feasible approach to use when assessing global RV function in children with congential heart disease.     

Long-Term Outcome of Children with Complete Heart Block Diagnosed After the Newborn Period

The aims of this study were to assess morbidity, mortality, and long-term cardiac outcome of children with congenital complete heart block (CHB) diagnosed between the ages of 3 months and 15 years. The study population consists of 61 children with CHB diagnosed in five tertiary referral centers in Finland. There were two study groups: CHB diagnosed 3 months to 2 years of age (group 1; n= 29) and CHB diagnosed between the age of 2 and 15 years (group 2; n= 32). Neonatal morbidity was significantly higher in group 1 than in group 2 (p= 0.047). In the whole study population, permanent pacemaker implantation with the main indications of low ventricular rate and syncope (52%) was performed in 80% of cases, with a median age of 11.2 years. Structural heart defect not causally associated with CHB was evident in 9 of 61 patients (15%). Of 8 patients with atrial septal defect (ASD) secundum, 6 (75%) were operated on and 7 (88%) were paced. One patient had small ventricular septal defect. The incidence of dilated cardiomyopathy was 7%. The mortality with cardiomyopathy was very high (75%). Of the 61 children, 3 (5%) died due to cardiomyopathy at the ages of 2, 26, and 31 years. In the long-term follow-up of 17 years (median, range 2.9–46 years) 17% of patients who survived had cardiac problems: arrhythmias in 5, mitral valve insufficiency in 3, ASD secundum in 1, and cardiomyopathy in 1. The long-term outcome did not depend on the age at which CHB was diagnosed. In conclusion, CHB diagnosed after the newborn period carries relatively low mortality and morbidity. Pacemaker application was indicated in most children. The possibility of an associated heart defect or dilated cardiomyopathy indicates regular echocardiographic monitoring in all children and young adults with CHB.     

Noninvasive Prediction of Pulmonary Artery Pressure in Patients with Isolated Ventricular Septal Defect

Management of patients with isolated ventricular septal defect (VSD) requires information regarding pulmonary artery pressure (PAP). The purpose of this study was to evaluate the individual predictive value of noninvasive methods for assessment of PAP and to determine if any combination of techniques significantly improved their predictive power. We reviewed the clinical history, electrocardiogram, and echocardiogram of 31 patients (age 1.9 ± 1.73 years) who underwent catheterization for isolated VSD. Noninvasive data were compared for patients with mean PAP <20 mmHg (group 1) and those with mean PAP ≥20 (group 2) at catheterization. Fourteen (45%) patients were in group 1 and 17 (55%) in group 2. Doppler estimation of VSD gradient, right ventricular hypertrophy by echocardiogram, interventricular septal orientation, and VSD size had predictive value for elevated mean PAP (p < 0.01). All patients (n= 6) with normal findings in all four variables had normal PAP. All patients (n= 12) with at least three of four abnormal findings had elevated PAP. Six patients in group 1 had at least one variable that incorrectly predicted high PAP, whereas 3 patients with normal findings on three of the four variables nevertheless had elevated PAP. No single noninvasive variable accurately predicted PAP in all cases. However, normal findings for all four significant variables did predict normal PAP and suggest that cardiac catheterization is unnecessary in that setting. However, any other combination of normal and abnormal findings for the four significant variables did not reliably predict PAP and such patients may require catheterization to directly measure PAP.     

Congenital complete heart block in the fetus: hemodynamic features, antenatal treatment, and outcome in six cases

Congenital heart block (CHB) can result in intrauterine cardiac failure leading to fetal or neonatal loss. To establish perinatal hemodynamic factors which might predict adverse outcome, six fetuses with CHB diagnosed between 20 and 30 gestational weeks were examined by echocardiography at 2-week intervals. Neonatal morbidity and outcome in infancy are detailed. The fetuses showed a significant decrease in ventricular rate (VR) with advancing gestation (60 ± 7 vs 51 ± 4 beats/min, p= 0.03). Cardiac decompensation defined as hydrops or pericardial effusion was associated with VR of lower than 55 beats/min in two fetuses. Three mothers had a therapeutic trial with a sympathomimetic and digoxin. Salbutamol increased VR 10% in one of three fetuses treated. Digoxin decreased pericardial effusion in one hydropic fetus with autoimmune myocarditis. In this fetus, poor left ventricular fractional shortening (LVFS) was accompanied with high umbilical artery resistance index (RI). High amniotic fluid erythropoietin indicated severe hypoxia preceding death. Pacemaker was indicated in all the newborns. At the age of 2 weeks all the surviving infants had tricuspid regurgitation and a shunt through foramen ovale due to asynchronized atrioventricular contraction. During the 12-month follow-up two of five surviving infants had no symptoms. One had symptomatic neonatal lupus. Two infants had patent ductus arteriosus, one with dilated cardiomyopathy. In conclusion, poor fetal outcome was associated with low VR, low LVFS, and high RI. Despite early pacing, morbidity was high in infancy due to cardiomyopathy and associated heart defects. Regular echocardiographic monitoring during pregnancy and after delivery is required in order to optimize care and timing of any interventions.     

Three-Dimensional Echocardiographic Measurement of Left Ventricular Stroke Volume in Children: Comparison with Doppler Method

Three-dimensional echocardiography (3DE) allows calculation of ventricular volumes without geometric assumption on the ventricular shape. Our aim was to apply 3DE in a normal pediatric population and to compare the left ventricular stroke volume measurements to the Doppler method. Twenty-four normal patients (median age 7 years) underwent Doppler echocardiography and 3DE for left ventricular stroke volume calculation. The left ventricular stroke volume by Doppler method was calculated as the product of the aortic Doppler flow mean velocity and the area of the aortic annulus. The 3DE method was performed using a transthoracic rotational probe (TomTec) and left ventricular volumes were calculated using the Simpson's rule. The mean time for 3DE acquisition was 90 seconds without any sedation. 3DE correlated well with the Doppler method for left ventricular stroke volume measurements (y= 0.8x− 0.2, r= 0.94). The mean difference between the average values of left ventricular stroke volume obtained by Doppler method and 3DE was 5 ± 4 ml. Intraobserver and interobserver variabilities in the left ventricular stroke volume measurement by 3DE were 2.6% and 4.4%. In conclusion, 3DE compared to the Doppler method is an accurate, noninvasive, and reproducible method to measure the left ventricular stroke volume in normal children.     

Acute loads applied to the right ventricle: Effect on left ventricular filling dynamics in the presence of an open pericardium

To determine whether diastolic ventricular interdependence mechanisms would act in the presence of an open pericardial sac, as during cardiac surgery, moderate acute right ventricle afterload increases were applied to eight dogs with the chest and pericardium open while left ventricular filling dynamics were being assessed by Doppler echocardiography. Dogs were studied under basal conditions and after acute banding of the main pulmonary artery tightened to produce a 100% increase in right ventricular systolic pressure. With banding, the left ventricular filling velocity ratio (E/A), as assessed by Doppler echocardiography of mitral inflow, changed from a baseline value of 1.32 ± 0.05 to 1.16 ± 0.03 (p < 0.02), suggesting a restrictive pattern to early left ventricular filling, which is differed to that during the second half of diastole. Isovolumic relaxation time, measured as the time interval between aortic valve closure and mitral valve opening, assessed by M-mode echocardiography of both valves, was prolonged, though not significantly, from 63.3 ± 2.5 ms to 69.4 ± 2.9 ms, by banding of the pulmonary artery. E wave deceleration time, a filling variable influenced by chamber pressure/volume relations, was shortened by pulmonary artery banding, changing from 75.1 ± 1.7 ms to 68.0 ± 1.8 ms (p < 0.01). It was concluded that pressure loads applied to the right ventricle restricted early left ventricular filling. Prolonged relaxation and altered pressure–volume chamber relations were the diastolic interdependence mechanisms involved that proved to be acting even under open pericardium conditions.     

Severe Left Ventricular Dysfunction and Arrhythmias as Complications of Gram-Positive Sepsis: Rapid Recovery in Children

Severe left ventricular dilatation and dysfunction in children may be associated with poor outcome in as many as 45% of cases. The prognosis for children with poor left ventricular function or arrhythmias associated with septic shock may be better, however, this has been inadequately studied. We report the favorable outcome of three children who presented with Gram-positive sepsis and significant cardiovascular compromise—two with severely dilated, poorly contractile left ventricle, and one with mild left ventricular dysfunction and incessant, malignant, and rapid atrial and ventricular arrhythmias. Our experience with these patients shows that complete and rapid resolution of these complications may be achieved with aggressive therapy.     

Age-Related Variation in Left Ventricular Myocardial Contractile State Expressed by the Stress Velocity Relation

The assessment of ventricular function plays an important role in the pre- and postoperative management of many congenital heart abnormalities. Normal ranges in left ventricular systolic function indices have been defined during childhood and age-related alterations in left ventricular myocardial contractile state have recently been reported. This study was carried out to investigate the developmental changes in left ventricular contractile state expressed by the endsystolic meridional stress (ESS)/rate-corrected velocity of circumferential fiber shortening (VCFc) relation, calculated by echo in normal children and young adults. We examined 146 healthy subjects (80 males and 66 females), mean age 70.85 ± 63.89 months (range 0.5–228) and body surface area (BSA) 0.807 ± 0.47 (range 0.18–2.01) with no clinical and echocardiographic evidence of cardiac disease and with normal blood pressure. The subjects were divided into three groups according to age: <6 months (group 1, n= 32), 6–36 months (group 2, n= 34), and >36 months (group 3, n= 80). Enddiastolic volume and mass (M) of the left ventricle were measured by M-mode Echo. ESS was considered as an index of afterload and the VCFc as an index of systolic ventricular function. The left ventricular ejection time used for the calculation of VCFc was measured from aortic flow obtained by PW–Doppler. The ESS/VCFc relation was used to assess left ventricular contractility. Systolic blood pressure, volume, and mass of the left ventricle increase with age. The gradual increase in pressure despite a stable mass/volume ratio [M/V = 0.900 + (0.0007 × age); r= 0.27, p < 0.005] resulted in a substantial increase of afterload [ESS = 29.78 + (0.116 × age); r= 0.58, p < 0.0001]. VCFc showed an inverse hyperbolic regression with afterload [VCFc = 1.01 + (7.598/ESS); r= 0.59, p < 0.0001]. The regression lines (best linear fit) between VCFc and ESS are significantly different in the three groups. The Y intercept was higher and the slope steeper in group 1 [VCFc = 1.74 − (0.017 × ESS); r= 0.65, p < 0.0005] vs group 2 [VCFc = 1.54 − (0.008 × ESS); r= 0.58, p < 0.001] and group 3 [VCFc = 1.52 − (0.007 × ESS); r= 0.57, p < 0.0001]. These data indicate that, in children, the volume and mass of the left ventricle increase, whereas the M/V ratio remains relatively constant; the progressive increase in arterial blood pressure explains the increase of afterload. The VCFc is higher in the first few years of life compared to that seen in older children due to reduced afterload and increased contractile state. Left ventricular contractility, expressed as ESS/VCFc relation, is thus inversely proportional to age. In the first months of life the left ventricular myocardium exhibits a higher basal contractile state and a greater sensitivity to changes in afterload. For obtaining an accurate assessment of left ventricular function, the ESS/VCFc relation in different age groups should be measured.     

Early Postoperative Results After Total Correction of Tetralogy of Fallot in Older Patients: Is Primary Repair Always Justified?

The objective of this study was to compare early postoperative results in primary vs 2-stage repair of tetralogy of Fallot in patients operated on after 5 years of age. Eighty-four patients with tetralogy of Fallot were studied, who were more than 5 years of age and who were repaired in one center by one surgeon. Hospital death and ratio of right-to-left ventricle pressure after correction were compared between the primary and the 2-stage groups as early outcome indices. Overall hospital mortality was 11.9% (10/88). There were 9 (18.4%) hospital deaths in the primary and 1 (2.9%) in the 2-stage group. Mortality was significantly higher in the primary group (p= 0.04 using the 2-tailed Fisher's exact test; relative risk = 6.43; 95% CI = 0.85–48.46). The mean ± standard deviation (SD) for RV/LV ratio was 0.51 ± 0.13. It was 0.61 ± 0.11 in patients who died and 0.49 ± 0.12 in patients who lived (p= 0.01 using the 2-tailed t-test). RV/LV ratio was not significantly different between either group. In the 2-stage group, there was a small inverse correlation between the time interval and the RV/LV ratio (correlation coefficient =−0.235). The TAP group had a statistically significant lower time interval between shunt and total correction than the RVOT-P group (p= 0.02 using 2-tailed t-test). Older patients generally do better on 2-stage repair, because of their age. A long period of low pulmonary blood flow has induced unbalanced ventricles and exaggerated RVOTO for these patients because of muscle hypertrophy. In such patients, shunting will prepare the left ventricle for accepting the extra blood volume that will reach the left ventricle after total correction.     

Cost-Effectiveness Analysis of Stents,Balloon Angioplasty,and Surgery for the Treatment of Branch Pulmonary Artery Stenosis

Branch pulmonary artery stenosis is a common problem in pediatric cardiology. Treatment has included surgery, balloon angioplasty, and balloon expandable stent placement. It was the purpose of this investigation to demonstrate the cost-effectiveness of each of these modes of treatment. From 1983 to 1994 there were 30 patients admitted for treatment of branch pulmonary artery stenosis only. Data included age at procedure, sex, primary diagnosis, acute and intermediate term success, and complications. Acute success was defined by results at the end of the procedure where intermediate term (IT) success was defined by results at follow-up. Success of a procedure was defined by at least one of the following: an increase in vessel diameter by ≥50% of predilation diameter, a decrease in right ventricular to left ventricular or aortic systolic pressure ratio by ≥20%, or a decrease in peak to peak pressure gradient by ≥50%. The procedure was considered a failure if the previously mentioned criteria were not met or if the patient required a second procedure for the same stenosis. The expense of the procedure (estimated by using the patient charges) were collected from the time of the procedure until December 1994. Because of differing lengths of follow-up, the patients were analyzed separately for procedures and outpatient charges. The total charges were corrected to 1994 dollars using the Medical Consumer Price Index. Thirty patients had 46 separate procedures (12 patients had >1 procedure and 3 had >2 procedures). There were 13 surgeries, 13 balloon angioplasties, and 20 stents. Stents were the most successful (90% acute and 85% IT), but were not statistically superior to surgery (62% acute and IT). Balloon angioplasty was significantly less successful as compared with stents (31% acute and 23% IT), and was not statistically different from surgery over the acute and intermediate term. The charge data showed balloon angioplasty was the least expensive followed by stents and then by surgery. The average total charges per procedure, including outpatient charges, were: surgery $58,068 ± $4372 (standard error), balloon $21,893 ± $5019, stents $33,809 ± $3533 (p < 0.001); excluding outpatient charges: surgery $52,989 ± $3649, balloon $15,653 ± $1691, and stents $29,531 ± $2241 (p < 0.001). Average total charges per patient, including all procedure types and grouped by initial procedure, were: surgery $53,707 ± $6388, balloon $50,040 ± $8412, and stent $34,346 ± $3488 (p= 0.047). Stents were at least as effective as surgery and were more effective than balloon angioplasty in both acute and intermediate term follow-up. Balloon angioplasty was least expensive per procedure but was also least effective. Therefore, intravascular balloon expandable stents are the most cost-effective means available in the treatment of branch pulmonary artery stenosis.