Right ventricular performance and pulmonary haemodynamics in adolescent and adult patients with cystic fibrosis

A combined haemodynamic and radionuclide approach was used to evaluate right ventricular performance in 16 adolescent and adult patients with cystic fibrosis (CF). There were nine patients with mild arterial hypoxaemia (PaO₂>80% of predicted) and normal resting pulmonary artery pressure and seven patients with severe arterial hypoxaemia (PaO₂<70% of predicted) and resting pulmonary arterial hypertension (PH). The right ventricular ejection fraction (RVEF) by equilibrium angiocardiography using krypton 81^m as a tracer and stroke volume index (SVI) by thermodilution techniques were measured simultaneously and right ventricular end-diastolic and end-systolic volumes were derived. RVEF was normal in CF patients without PH (58.9±7.2%) but was reduced in those with PH (45.4±2.6%). There was a statistically significant inverse linear correlation between RVEF and afterload as assessed by mean pulmonary artery pressure and pulmonary vascular resistance (PVR: r=–0.78), indicating that RVEF ist afterload-dependent. Right ventricular function, however, as assessed by right ventricular end-systolic pressure-volume relations was even higher in CF patients with PH, indicating preserved or even increased right ventricular function in the face of an increased afterload stress.Abbreviations CF cystic fibrosis - PaO₂ arterial oxygen tension - PH pulmonary arterial hypertension - RVEF right ventricular ejection fraction - SVI stroke volume index - Pap pulmonary artery pressure - PVR pulmonary vascular resistance - COPD chronic obstructive pulmonary disease - VC vital capacity - FEV₁ forced expiratory volume in 1 s - RV resisdual volume - TLC total lung capicity - RVEDP right ventricular end-diastolic pressure - Pap_s systolic pulmonary artery pressure - Pap_d diastolic pulmonary artery pressure - PCWP pulmonary capillary wedge pressure - CO cardiac output - ED end-diastolic background-corrected counts - ES end-systolic background-corrected counts - CI cardiac index - RVEDVI right ventricular end-diastolic volume index - RVESVI right ventricular end-systolic volume index - P/V relation right ventricular end-systolic pressure/right ventricular end-systolic volume index - S-K score Shwachmann-Kulczycki score     

Left ventricular function and myocardial mass after aortic valvotomy in infancy

Summary Eighteen of 25 survivors of aortic valvotomy in infancy were reinvestigated by cross-sectional echocardiography a mean of 7.5 (2.3–13.4) years after surgery. They had been operated at a median age of 38 (5–330) days. At the follow-up examination the gradient across the aortic valve was 41±19 (15–85) mmHg and the ejection fraction was 0.73±0.10 (0.48–0.84). Left ventricular (LV) end-diastolic volume was 66±17 (33–191) ml/m². LV mass was 96±36 (44–204) g/m² and the LV mass volume index (LVMVI) (mass divided by end-diastolic volume) was 1.43±0.4 (0.9–2.28). Eleven of 18 patients had an abnormally high mass volume index compared with 95 age-matched controls with structurally normal hearts. The correlation between the residual pressure gradient across the aortic valve and mass volume index yielded anr value of 0.75 (p<0.0004). One patient had been reoperated and underwent resection of a subaortic stenosis 4 years after the initial operation. Four patients with a resting gradient of more than 50 mmHg and one with grade 4 aortic regurgitation are scheduled for further surgical treatment.We conclude that, although LV function was normal in most patients who underwent aortic valvotomy in infancy, LV mass remains elevated in a significant number of patients, who may remain at risk of developing subendocardial ischemia.     

Myocardial oxygen consumption,cardiac work,and myocardial efficiency in children

Few reports on human cardiac functional development exist, although this information is important for managing paediatric heart disease. The work and the energy usage of the heart was measured in children. A total of 58 patients (aged 1–19 years) with a history of Kawasaki disease without coronary sequelae underwent cardiac catheterization to obtain haemodynamic data and to measure myocardial oxygen consumption. Myocardial oxygen consumption (ml/min) (y=0.63 x+3.6,r=0.86,P<0.0001,x=age) and left ventricular minute work (kg m/min) (y=0.46 x+2.4,r=0.84,P<0.0001, x=age) correlated positively with age. However, left ventricular minute work per body surface area (age: 2–5 years, 5.8±0.34 kg m/min/m²; age: 6–10 years, 6.9±0.59 kg m/min/m²; age: 11–15 years, 5.9±0.51 kg m/min/m²; age: 16–19 years, 6.5±0,29 kg m/min/m²; and myocardial efficiency (age: 2–5 years, 40.1±4.4%; age: 6–10 years, 42.4±3.9%; age: 11–15 years, 45.9±4.1%; age: 15–19 years, 42.3±6.6%) remained constant throughout childhood.Conclusion In spite of the structural immaturity of the developing heart, the myocardial oxygen consumption per body surface area and myocardial efficiency led by the cardiac work are the same in adults and in children older than 1 year of age.     

Left Ventricular Mass in 169 Healthy Children and Young Adults Assessed by Three-Dimensional Echocardiography

The aims of this study were to establish normal values of left ventricular (LV) mass in children and young adults using three-dimensional echocardiography (3-DE) and to compare 3-DE LV mass estimates with those obtained by conventional echocardiographic methods. We studied 169 healthy subjects aged 2–27 years by digitized 3-D, two-dimensional (2-D), and M-mode echocardiography. 3-D echocardiography was performed by using rotational acquisition of planes at 18° intervals from apical view with ECG gating and without respiratory gating. 3-DE gave smaller LV mass estimates than 2-DE and M-mode echocardiography (p < 0.001). Agreement analysis resulted in a bias of −9.3 ± 36.5 g between 3-DE and 2-DE, and −18.5 ± 47.9 g between 3-DE and M-mode. For the analysis, the subjects were divided into five groups according to body surface area (BSA): 0.5–0.75, 0.75–1.0, 1.0–1.25, 1.25–1.5, and greater than 1.5 m². LV mass/BSA by 3-DE was 45.6 (5.1), 54.3 (7.7), 55.2 (7.9), 58.8 (8.1), and 65.0 (9.9) g/m². LV mass/end diastolic volume (EDV) by 3-DE was 0.9 (0.1) g/ml in the BSA group of 0.5–0.75 m² and 1.0 (0.2) g/ml in the other BSA groups. LV mass increased linearly in relation to BSA, height, and body mass (r = 0.93, 0.90, and 0.92, respectively; p < 0.001 for all). The results showed a linear increase in LV mass, whereas LV mass/EDV ratio remained unchanged. However, LV mass estimates by 3-DE were lower than those obtained by 2-DE and M-mode echocardiography. The data obtained by 3-DE from 169 healthy subjects will serve as a reference for further studies in patients with various cardiac abnormalities.     

Prediction of Postoperative Left Ventricular Pump Function in Congenital Mitral Regurgitation

In adult patients with severe chronic mitral regurgitation, many predictors for estimating postoperative left ventricular systolic function have been proposed. However, none has been defined in children. We analyzed the relationship between such predictors and postoperative left ventricular fractional shortening in children with isolated congenital mitral regurgitation. Eight patients with isolated congenital mitral regurgitation were examined before and after surgery with echocardiography. Fractional shortening, left ventricular end-diastolic and end-systolic dimension indices, and left ventricular end-systolic wall stress/left ventricular end-systolic dimension index in the preoperative status were poorly correlated with postoperative left ventricular fractional shortening. Predictive wall stress, which was calculated from preoperative data of end-diastolic dimension, end-diastolic wall thickness, and diastolic blood pressure, correlated well with postoperative left ventricular fractional shortening (r=−0.90, p= 0.0024). It is important to consider not only myocardial contractility but also postoperative afterload for estimating postoperative left ventricular performance in chronic severe mitral regurgitation.     

Right ventricular size and function as assessed by echocardiography and angiography in patients with different volume load

A comparative study of right ventricular (RV) function, assessed by echocardiography and angiography, undertaken in 20 patients, 10 of whom had atrial septal defects (ASDs) and 10 had various other heart diseases. All of the measured echocardiographic variables of RV size, apart from RV length, were larger in the patients with ASD. When assessed by multiple regression analysis, the RV M-mode dimension was an independent variable of RV angiographic end-diastolic volume (EDV) in patients without RV volume load (R=0.92,R ²=0.85,p<0.001). In the patients with ASD, echocardiographic RV end-diastolic area was an independent variable of angiographic RVEDV (R=0.75,R ²=0.55,p<0.05), whereas M-mode dimension had a weaker correlation (r=0.29). The agreement between RV ejection fraction (RVEF) obtained by echocardiography and angiography was moderate in both patient groups. However, fractional area change and fractional length change could not estimate RVEF better. Thus care should be taken to use single measurements and derivatives as the only parameters of RV size and function.     

Effects of low-dose dobutamine on left ventricular diastolic filling in children

To investigate the effects of dobutamine on the Doppler transmitral flow pattern in children with normal left ventricular function, Doppler echocardiography was used to measure the transmitral flow in 14 healthy children before and during infusion of dobutamine (5 μg/kg per minute). Cardiac output was measured by the thermodilution method, and stroke volume was calculated as the cardiac output divided by the heart rate. Dobutamine increased the peak velocity and flow velocity–time integral of early diastolic filling without changing those of atrial contraction and normalized peak velocity of early diastolic filling, suggesting an increase in left ventricular relaxation. Dobutamine increased the stroke volume and rate-corrected mean velocity of fiber shortening with reduced end-systolic wall stress, indicating an increase in left ventricular contractility. The percentage of increase in the flow velocity–time integral of early diastolic filling during dobutamine infusion tended to correlate with the increase in stroke volume (r= 0.67, p < 0.05) and with the decrease in end-systolic wall stress (r=−0.61, p < 0.05). Our results suggest that low-dose dobutamine increases left ventricular relaxation with enhanced systolic function. The observed decreased end-systolic wall stress might have caused enhanced relaxation characteristics with dobutamine.     

Noncompaction Cardiomyopathy in Children With Congenital Heart Disease: Evaluation Using Cardiovascular Magnetic Resonance Imaging

Noncompaction of the left ventricle, a genetic cardiomyopathy with a reported incidence of 0.05% to 0.24%, can lead to sudden cardiac death, particularly among children, if left undetected. Because the diagnosis of isolated noncompaction cardiomyopathy (NCM) can be overlooked, its association with other congenital heart diseases (CHDs) makes the diagnosis of NCM even more difficult. This study aimed to assess the impact of NCM on the cardiovascular physiology of children with coexisting CHDs evaluated by cardiovascular magnetic resonance imaging. A case-control study was performed with 12 children (6 patients with combined NCM and CHD and 6 control subjects with isolated CHD). The mean left ventricular end-diastolic and end-systolic volume indices were significantly higher in the CHD patients presenting with NCM than in the CHD patients with no NCM (P = 0.028). However, no differences were observed for right ventricular end-diastolic and end-systolic volume indices, biventricular ejection fractions, stroke volumes and indices, left ventricular wall thickness, left ventricular fractional shortening, cardiac output, or cardiac index. This study suggests that NCM in children with CHDs increases left ventricular volumes, and larger studies are required to demonstrate other changes (e.g., ejection fraction, stroke volume) that were close to being significant.     

Contractility Reserve in Children Undergoing Dialysis by Dobutamine Stress Echocardiography

Left ventricular hypertrophy is an adaptive mechanism in children undergoing chronic dialysis to improve contractility at rest. The aim of this study was to determine the left ventricular performance and contractility reserve by “dobutamine stress echocardiography” in children undergoing chronic dialysis. Thirty-five children undergoing dialysis and 24 healthy subjects were enrolled in this prospective study. We evaluated contractility by means of end-systolic wall stress—velocity of circumferential fiber shortening (VCFc) in 24 healthy subjects and 35 dialysis patients. Dobutamine stress echocardiography was obtained only in children undergoing dialysis. Patients were divided into two groups according to left ventricular mass index. Contractile reserve was estimated by the difference in contractility at rest versus during echocardiography. Significantly higher VCFc (p = 0.008) and VCFc (p = 0.002) differences at rest were observed in the patient group compared to healthy subjects. Children undergoing dialysis had a higher left ventricular mass index compared with controls (42.38 ± 12.41 vs. 17.57 ± 3.66 g/m^2.7, respectively; p = 0.001). Patients with left ventricular hypertrophy had a significantly lower contractile reserve compared with patients without left ventricular hypertrophy (p = 0.013). These findings suggest that children undergoing dialysis have increased left ventricular mass and contractility at rest. However, the contractile reserve during dobutamine stress echocardiography was reduced. Dobutamine stress echocardiography may identify children undergoing dialysis at risk of progressing to systolic dysfunction and heart failure.     

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.     

Effect of patent ductus arteriosus on doppler-derived right ventricular systolic time intervals

Summary Right ventricular systolic time intervals (RVSTI) and noninvasive Dopplerderived pulmonary blood flow were measured before and after surgical ductus ligation in 18 otherwise healthy infants and children who were older than 3 months of age. Right ventricular preejection period (PEP) and the ratio of preejection period and right ventricular ejection time (PEP/REVET), both corrected or uncorrected for heart rate, decreased significantly following surgery (PEP 71±14 vs. 50±13,p<0.001 and PEP/RVET 0.29±0.06 vs. 0.21±0.05,p<0.001). The volume of pulmonary blood flow correlated with PEP/RVET (r=0.48,p=0.003). The magnitude of the change in pulmonary blood flow correlated with the change in PEP/RVET (r÷0.56,p=0.016). The velocity of circumferential fiber shortening (VCFc) increased after surgery, but not significantly. We speculate that patent ductus arteriosus has a similar effect on right ventricular performance when other congenital heart defects are present.     

Early detection of doxorubicin and daunorubicin cardiotoxicity by echocardiography: Diastolic versus systolic parameters

Doxorubicin and daunorubicin are effective anticancer agents in children, however, their therapeutic value is limited by myocardial cardiotoxicity. In 14 children (median age 5,0 years, range 3–12) prospective studies were performed using pulsed Doppler echocardiography to assess the changes in left ventricular systolic and diastolic filling dynamics. None of these children developed cardiomyopathy. M-mode echocardiographic systolic parameters and Doppler transmitral flow velocities were analysed at baseline, after a cumulative anthracycline dose of 138±26 mg/m² (second examination) and after 240±15 mg/m² (third examination). At the second examination the acceleration time/ejection time ratio was significantly reduced (P<0.01), but this was no longer evident at the third examination. There was no significant change of peak velocity over aortic valve, preejection period and change of velocity over time. In contrast, three diastolic parameters changed significantly; the late over early inflow velocity (P<0.05), mitral valve late time velocity integral (P<0.01 at the second andP<0.05 at the third examination) and the ratio A-TVI/TVI (P<0.025 andP<0.01). At the third examination the velocity of the A wave was also significantly increased.Conclusion In anthracyline treated children left ventricular diastolic function deteriorates before systolic function. Diastolic function parameters should be used rather than systolic parameters to monitor these patients.     

Echocardiographic findings in mild and severe forms of sickle cell anemia

M-mode echocardiographic findings were compared between sickle cell anemic and healthy children. Patients were composed of two groups; Group 1: mild group with no crises, no blood transfusions at the ages of 5.0 to 13.0, total of 12 children; Group 2: severe group, with frequent crises with requirement of blood transfusions at the ages of 3.0 to 13.0 years, total of 18 children. Control group was composed of 12 healthy children aged 5.0 to 13.0. When M-mode echocardiographic findings were compared, important findings were as follows: Mean left atrium dimension was increased both in the mild and severe groups (P < 0.001) compared with controls. This finding also supports the increase in the left ventricle end-diastolic dimension in both the severe and mild groups as compared with controls (P < 0.001). The increase in end-diastolic left ventricle dimension could be due to anemia present in the patients, but there was no difference between the two patient groups. Posterior left ventricle thickness and left ventricle mass was increased in both the mild and severe groups compared with controls (P < 0.001, P < 0.05), respectively. Left ventricular fractional shortening was more or less the same with controls. In spite of left ventricular volume load and dilatation, left ventricular contraction was good and systolic function was normal, and there was no correlation between the ECHO findings and hematological indices.     

The late consequences of anthracycline treatment on left ventricular function after treatment for childhood cancer

The purpose of this study was to determine the incidence of changes in left ventricular function in patients in long-term remission after treatment with anthracyclines for a childhood malignancy. The authors examined 155 patients in disease remission who underwent treatment protocols utilising anthracyclines in childhood. The group comprised 90 males and 65 females aged 15±4.9 years (range 5–29 years, median 15 years). The age at the time of diagnosis and start of treatment was 8.6±4.9 years (range 1–18 years, median 8 years). The time of follow-up was 7.3±4 years (range 1–21 years, median 6.3 years). The patients were given a cumulative dose of doxorubicin or daunorubicin of 250±131 mg/m² (range 50–1200 mg/m², median 240 mg/m²). The values of ejection fraction below 55% and fractional shortening below 30% assessed by means of echocardiography were considered as pathological. The control group consisted of 41 volunteers. Pathological values of fractional shortening were found in 12 patients (8%). Only one patient (0.64%) showed the development of heart failure due to cardiomyopathy. The group of the patients after chemotherapy revealed significantly worse values of left ventricular endsystolic wall stress, mean velocity of circumferential fibre shortening, Tei index, and isovolumic relaxation period in comparison with the control group. We found a correlation between the given cumulative dose of anthracyclines and indicators of systolic function of the left ventricle, but not a relation to the time indicators (age at diagnosis, time of follow-up). Conclusion:in the mean period of 6 years after chemotherapy, subclinical cardiotoxicity was found in 11 patients (7%) and cardiomyopathy with heart failure in one patient. Further indicators of subclinical damage are elevation of afterload (end-systolic stress), impaired relaxation and increased value of the Doppler index of global left ventricular function. Further monitoring and evaluation of the relevant subclinical abnormalities over a longer period of time are needed.Abbreviations CD cumulative dose - DT deceleration time - E/A index of the diastolic filling of the left ventricle - EF ejection fraction - ESS end-systolic stress - FS fractional shortening - HR heart rate - IRT isovolumic relaxation time - LV left ventricle - LVPWDd end-diastolic diameter of the left ventricular posterior wall - LVPWex excursion of the left ventricular posterior wall - LVPWP percentage of the systolic thickening of the left ventricular posterior wall - MPI myocardial performance index - mVcf _c mean velocity of circumferential fibre shortening     

Validation of the Proximal Isovelocity Surface Area Method for Assessing Mitral Regurgitation in Children

The proximal isovelocity surface area (PISA) method for calculating volume flow through the regurgitant orifice has attracted significant attention. A number of in vitro studies and clinical studies in adults suggest that the method is accurate. However, when applying the method to children it must be noted that the absolute regurgitation volume is small, and the range of body sizes is wide. This study investigated the accuracy of the PISA method for quantitative assessment of the severity of mitral regurgitation in children. Twenty children aged 7 months to 12 years (average 4.7 years) with mitral regurgitation but without interventricular shunt or aortic stenosis were selected for this study. Underlying cardiac diseases included atrioventricular septal defects in nine, isolated mitral regurgitation in five, and association with other heart defects in six. The PISA radius (r) and the duration of regurgitation (T) were measured on color M-mode recordings, with the M line passing through the center of the PISA. Assuming that the PISA is a hemisphere, maximal regurgitant flow rate (MFR: ml/s) was calculated as MFR = 2π×~ r ²×~ V (r= maximal radius, V= aliasing velocity), and regurgitant stroke volume (RSVpisa) as RSVpisa = 2π×~ MSR ×~ V×~ T (MSR = mean square of the PISA radius during regurgitation). As a validating standard, total stroke volume (TSV) using two-dimensional echocardiography determined by the area–length volumetry method and forward stroke volume (FSV) by the pulsed Doppler method were measured, and regurgitant stroke volume (RSV_D: RSV_D= TSV − FSV) and regurgitant fraction (RF: RF = RSV_D/TSV) were calculated. A linear correlation was found between MFR, RSVpisa, and RSV_D (X) (MFR = 4.2X + 54.0, r= 0.84. RSVpisa = 1.0X + 9.8, r= 0.90), and both RSVpisa and MFR divided by body surface area (BSA: m²) revealed a significant correlation with regurgitant fraction (X) by nonlinear regression analysis (RSVpisa/BSA = 26.2 ×~ X/(1 − X) + 16.8, r= 0.85. MFR/BSA = 121.8 ×~ X/(1 − X) + 92.2, r= 0.79). It is concluded that maximal regurgitant flow rate, regurgitant stroke volume, and regurgitant fraction can be accurately predicted in children using the PISA method by Doppler echocardiography.     

Acute hemodynamic effects of converting enzyme inhibition in children with intracardiac shunts

Summary The short-term hemodynamic effects of intravenous enalaprilat were assessed in 26 infants and children, aged 6 months to 15 years, with intracardiac shunts undergoing cardiac catheterization. Pulmonary and systemic pressure, flow, and resistance indices were measured by the direct Fick method before and 30 min after enalaprilat at 0.06 mg/kg.Aortic and pulmonary artery pressure decreased 15 and 20%, respectively, by 10 min, with little further change at 30 min. The heart rate did not change significantly and there was no reduction in systemic flow. In those with a large ventricular septal defect and normal or near-normal pulmonary resistance (<3.5 u.m²,n=8), the mean pulmonary-systemic flow ratio decreased from 2.9±0.3 to 2.4±0.3 (p<0.05) and the mean left-to-right shunt from 7.4±0.8 to 5.9±0.7 L/min/m² (p<0.02). Those with an elevated pulmonary vascular resistance (>5 u.m²,n=8) showed a varied response. Two children, both with Down's syndrome, an atrioventricular canal defect, and reversible pulmonary hypertension (as assessed by an infusion of isoproterenol), had no decrease in pulmonary vascular resistance with enalaprilat. There were no adverse effects.Converting enzyme inhibitors may benefit heart failure associated with large ventricular septal defects and normal or mildy elevated pulmonary resistance.     

Respiratory variation in echocardiographic dimensions of left and right ventricles in normal children

Summary Right and left ventricular (RV and LV) end-diastolic dimensions (RVD and LVD), LV end-systolic dimension (LVS), and interventricular septum thickness (IVS) were determined by means of echocardiography in 21 normal children and adolescents during quiet respiration. The RVD, IVS, and LVD were summed to obtain the total internal diastolic cardiac dimension (TID). Changes observed in RVD and LVD during respiration were opposite in direction and approximately equal in magnitude, so that TID remained essentially constant. The mean inspiratory increase in RVD was +3.37 mm ±0.23 mm SE and decrease in LVD was −3.71 mm ±0.32 mm. This difference was not statistically significant (p<0.001). The LVS decreased slightly from a mean of 2.7±0.1 cm to 2.6±0.1 cm (p<0.036). The LV end-diastolic volume (LVD vol), end-systolic volume (LVS vol) and stroke volume (LVSV) were calculated. Mean LVD vol decreased significantly during inspiration from 90.4±5.2 ml to 74±5.9 ml (p<0.001), whereas mean LVSV decreased from 57±3.2 ml to 42±3.2 ml (p<0.001). These data suggest to us that: 1. Theend-diastolic, total heart volume isnearly constant for a normal child at rest. 2. Respiration causes no significant change in thisnearly constant end-diastolic total heart volume. 3. Respiration, however,is associated withmotion of the IVS relative to the RVanterior wall and the LVposterior wall. 4. This relative motion of IVS partitions the nearly-constant end-diastolic total heart volume into RV and LV end-diastolic volumes which do change with the phases of respiration. 5. These respiratory changes in RV and LV end-diastolic volume are, respectively, opposite in direction and approximately equal in magnitude. Supported by a grant from Children's Heart Research Foundation.     

Importance of Plasma N-Terminal Pro B-Type Natriuretic Peptide, Epicardial Adipose Tissue, and Carotid Intima-Media Thicknesses in Asymptomatic Obese Children

This study aimed to analyze the variations of N-terminal pro B-type natriuretic peptide, epicardial adipose tissue thickness, and carotid intima-media thickness in childhood obesity. The study participants consisted of 50 obese children in the study group and 20 nonobese children referred for evaluation of murmurs who proved to have an innocent murmur and were used as control subjects. All the subjects underwent transthoracic echocardiographic examination for determination of left ventricular systolic function and mass index, myocardial tissue rates, and myocardial performance index. Epicardial adipose tissue thickness and carotid intima-media thickness also were measured during echocardiography. Serum N-terminal pro B-type natriuretic peptide levels were measured at the time of evaluation. The left ventricle mass index was 40.21 ± 10.42 g/m² in the obese group and 34.44 ± 4.51 g/m² in the control group (p > 0.05). The serum N-terminal pro B-type natriuretic peptide level was 109.25 ± 48.53 pg/ml in the study group and 51.96 ± 22.36 pg/ml and in the control group (p = 0.001). The epicardial adipose tissue thickness was 5.57 ± 1.45 mm in the study group and 2.98 ± 0.41 mm in the control group (p = 0.001), and the respective carotid intima-media thicknesses were 0.079 ± 0.019 cm and 0.049 ± 0.012 cm (p = 0.001). The left ventricular systolic and diastolic functions showed no statistically significant correlations with N-terminal pro B-type natriuretic peptide levels, carotid intima-media thickness, or epicardial adipose tissue thickness values. The results show that measurement of serum N-terminal pro B-type natriuretic peptide level, carotid intima-media thickness, and epicardial adipose tissue thickness in asymptomatic obese children is not needed.     

Cardiac function in survivors of acute lymphoblastic leukaemia and Hodgkin's lymphoma

Aim: The study objective was to assess plasma N‐terminal–pro‐brain natriuretic peptide (BNP) levels and to evaluate left ventricular mass as well as left ventricular systolic and diastolic functions in 44 children who had undergone treatment for acute lymphoblastic leukaemia and Hodgkin's lymphoma, with regard to gender, age at disease onset, time that had passed since therapy completion, cumulative dose of antracyclines and mediastinal radiotherapy applied. Methods: The median levels of pro‐BNP were found to be higher in the whole study group as compared with the control (55.9 ± 53.1 ng/mL vs. 38.5 ± 47.7 ng/mL, P= 0.059). The pro‐BNP values >80.0 ng/mL (standard deviation score (SDS)) were noted in 11/44 patients, including those exceeding 115.0 ng/mL (2 SDS) – in 6/44 patients. Results: No correlation was observed of pro‐BNP levels with the accumulated dose of antracyclines (r=?0.42, P= 0.79) or mediastinal radiotherapy (r= 0.197, P= 0.2). However, negative correlation was found between pro‐BNP and the time that had passed since therapy completion (r=?0.378, P= 0.009). In echocardiography, shortening and ejection fractions remained normal, whereas the indexed stroke volume was below 40 mL/m² in 16/44 patients. The E/A index below 1.5 was found in 6/44 cases. The left ventricular systolic mass remained within the normal range. Negative correlation was noted between isovolumetric diastolic time and pro‐BNP level. Conclusions: Increased levels of pro‐BNP after anti‐cancer treatment with the involvement of cardiotoxic substances may indicate the first symptoms of myocardial dysfunction, despite the lack of major echocardiographic disorders.     

Hemodynamic Correlates of Clinical Severity in isolated ventricular septal defect

Summary To test the hypothesis that the clinical assessment of severity in ventricular septal defect would be more related to variables which define tissue oxygen delivery than variables which define the left-to-right shunt, cardiac catheterization data from 40 children <3 years of age were assessed. Variables which were considered indicative of clinical severity included the need for digoxin and diuretics, resting heart rate, and severity of growth failure. Variables measured at cardiac catheterization, including those which related to oxygen transport, and assessment of left-to-right shunt, were considered independently. Patients receiving digoxin and diuretics were more tachycardic (142±18 vs. 111±26 beats/min, p<0.001) and had lower superior vena cava oxygen saturation (64±6 vs. 69±5%, p<0.01). Variation in heart rate (r ²=0.46) was best explained by oxygen consumption, hemoglobin concentration, cardiac index, and pulmonary vascular resistance. Variation in growth failure (r ²=0.15) was related only to the left ventricular forward stroke index. These data suggest that variables related to oxygen delivery, including oxygen consumption, hemoglobin concentration, cardiac index, forward stroke index, and superior vena cava oxygen saturation, are the major contributors to the clinical assessment of severity in ventricular septal defect.