Normal values of M mode echocardiographic measurements of more than 2000 healthy infants and children in central Europe

Left ventricular hypertrophy persists after successful treatment for coarctation of the aorta

OBJECTIVES

To evaluate cardiac size and function in patients with coarctation of the aorta (CoA) before and after treatment.

DESIGN

Ventricular size and function were examined by 2- and 3-dimensional echocardiography, and concentrations of natriuretic peptides measured in 15 paediatric patients before repair, and one, 6, and 12 months thereafter. Controls comprised 15 children.

RESULTS

Before repair, mitral inflow velocities and left ventricular (LV) size and wall thickness were higher in patients. Thicknesses of interventricular septum and LV posterior wall decreased after repair but increased to initial level one year thereafter. The LV end-diastolic diameter remained larger than in controls despite successful repair. The size of right ventricle increased and levels of natriuretic peptides decreased during follow-up. Levels of natriuretic peptides correlated with the smallest diameter of CoA segment and diastolic indices of LV function.

CONCLUSION

LV hypertrophy persists and LV size remains larger than in controls after successful repair even in normotensive patients with normal growth of CoA segment. This may be due to remodelling of ventricles and the aorta caused by CoA.

Assessment of left ventricular dyssynchrony and function using real-time 3-dimensional echocardiography in patients with congenital right heart disease

BACKGROUND

Patients after repair of congenital right heart disease (CRHD) may exhibit left ventricular (LV) dyssynchrony (LVD). However, the diagnosis of LVD is difficult and its reliability limited because current methods do not assess LVD of the whole LV simultaneously. The aim of the study was to assess LVD according to a novel global systolic dyssynchrony index (SDI) derived from real-time 3-dimensional echocardiography in patients after repaired CRHD.

METHODS

Two-dimensional echocardiography and real-time 3-dimensional echocardiography were performed in 30 patients after CRHD repair and in 30 matched healthy controls. Real-time 3-dimensional echocardiography data sets provided time-volume curves, and 2 global SDIs were derived from the dispersion of time to reach minimal systolic volume according to a 16- or 17-LV segment model.

RESULTS

Both SDIs were significantly elevated in the patient as compared with the control group (P < .001). A cutoff value for both SDIs was calculated and LVD defined as one of the SDIs exceeding cutoff. Left ventricular dyssynchrony was present in 5 (100%) of 5 patients with a LV ejection fraction (EF) <50% and 13 (52%) of 25 patients with preserved LVEF, thus being diagnosed in a total of 18 (60%) of 30 patients. Moreover, patients with LVD showed a significantly higher degree of pulmonary regurgitation (P = .01) with elevated right ventricular volumes and altered septal motion. Stepwise multivariate analysis identified LVEF (P = .005) and the degree of pulmonary regurgitation (P = .02) as independent predictors of LVD.

CONCLUSIONS

Left ventricular dyssynchrony can be detected in about 60% of patients after CRHD repair and is mainly due to significant pulmonary regurgitation resulting in an altered septal motion and systolic LV function.

Differences in left ventricular mass between overweight and normal-weight preadolescent children

This study examined cardiac and arterial differences between overweight and normal-weight preadolescent children. Twenty children (10.2 +/- 0.4 years of age) classified as overweight, on the basis of age-appropriate body mass index (BMI) cutoffs, were compared with 43 normal-weight controls. Height, mass, and body surface area were measured. Relative body fat and lean body mass were estimated from skinfold thickness. Each child's weekly physical activity metabolic equivalent (PAME) was calculated using a standardized questionnaire, and his or her sexual maturation was self-assessed using the Tanner scale. Peak aerobic power was assessed using a cycle ergometer and normalized to lean body mass. Mean arterial pressure was calculated from systolic and diastolic blood pressure (DBP) measurements taken with a Finapres. Cardiac dimensions were measured, using Mu-mode 2-dimensional echocardiography, and normalized to body surface area and height2.7. Left carotid artery pulse pressure (CaPP) was assessed with applanation tomometry. Overweight boys and girls had a higher left ventricular mass (LVM) and LVMHT2.7 than normal-weight boys and girls. CaPP was signficantly lower in the overweight than in the normal-weight groups, whereas PAME and relative peak aerobic power were significantly higher in the boys than the girls. Although overweight children had significantly higher stroke volumes and cardiac outputs than normal-weight children, ejection fraction was similar in the weight groups. Adjusted LVMHT2.7 was associated with cardiac volume measurements, BMI, and DBP in normal-weight children, whereas in the overweight children LVMHT2.7 did not significantly correlate with any variable. In conclusion, we found that cardiovascular adaptations can be seen in prepubescent overweight children as young as 10 years of age.

Does cardiac morphology predict plasma brain natriuretic Peptide levels in adolescent athletes?

OBJECTIVE

The purpose of this study was to establish the relationship of plasma levels of brain natriuretic peptide (BNP) to physiologic parameters and cardiac morphologic characteristics in a population of young athletes. Our hypothesis is that physiologic and cardiac morphologic characteristics do not predict BNP levels in adolescent athletes.

DESIGN

Observational study.

SETTING

Outpatient hospital.

PARTICIPANTS

Thirty healthy male adolescent high school football players (16.0 +/- 1.1 years).

INTERVENTIONS

Physical exam, electrocardiography, plasma BNP measurement by rapid fluorescent immunoassay, and limited echocardiography.

MAIN OUTCOME MEASURES

Null hypothesis-physiologic parameters and cardiac morphology do not predict plasma BNP levels in healthy adolescent football players. Significance level set at P < 0.05.

RESULTS

Plasma BNP for this population was 11.9 +/- 10.2 pg/mL. There was no correlation between BNP and mean arterial pressure (r = -0.09, P = 0.64), body mass index (r = 0.11, P = 0.57), interventricular septal thickness (r = -0.15, P = 0.44), left ventricular (LV) wall thickness (r = 0.00, P = 0.99), relative wall thickness (r = -0.04, P = 0.84), LV mass (r = 0.05, P = 0.79), or LV mass index (r = 0.11, P = 0.55).

CONCLUSIONS

Plasma BNP levels in healthy adolescent athletes have no correlation to body mass index or LV mass, even when corrected for body surface area.

Cardiomyopathy in newborns and infants: a broad spectrum of aetiologies and poor prognosis

AIM

This study set out to describe the initial clinical findings, morbidity, mortality and aetiology of infant cardiomyopathy focusing on potential risk factors for an adverse outcome.

METHODS

We retrospectively analysed clinical and laboratory findings of all patients diagnosed at our institution from 1995 to 2004 with cardiomyopathy within their first year of life.

RESULTS

Of the 35 patients, cardiomyopathy was classified as dilated in 18, hypertrophic in 14 and unclassified in 3. The aetiologies were genetic syndromes (8), metabolic diseases (5), familial isolated cardiomyopathy (3) and myopathy (1). During a median follow-up of 1.5 years (range 0-9 years), 13 patients died from progressive heart failure and two underwent heart transplants. Estimated survival and freedom from transplant was 69, 66, 58 and 50% after 0.5, 1, 2 and 6 years, respectively. Patients with severe heart failure symptoms within the first month of life had significantly worse outcomes than patients without heart failure symptoms.

CONCLUSION

High morbidity and poor prognosis result through progressive heart failure. Aetiology and clinical course are especially heterogeneous in infants. The most commonly identified aetiologies are genetic syndromes and metabolic diseases. A multidisciplinary approach is recommended for defining the aetiology and developing individual treatment strategies.

Echocardiographic and electrocardiographic trends in children with acute Kawasaki disease

BACKGROUND

Kawasaki disease (KD), while primarily an acute, self-limited, multisystem vasculitis, is more appropriately described as a pancarditis, from a cardiac perspective. Many patients are noted to have ventricular dilation on initial echocardiography; however, functional and structural measurements may remain within the normal range.

OBJECTIVE

The authors sought to determine echocardiographic and electrocardiographic trends after acute KD.

METHODS

Clinical data were reviewed on all patients presenting with acute KD to the Hospital for Sick Children (Toronto, Ontario). Patients with at least three electrocardiograms and echocardiograms over the first year post-KD were eligible. Mixed linear regression analysis for repeated measures was used to determine trends over time and associated factors.

RESULTS

One hundred seventy-six eligible patients were reviewed. Mean initial coronary artery diameter Z-scores were increased, with 4% having aneurysms. The mean (+/- SD) initial Z-score of ejection fraction was 0.40+/-0.84 (P<0.001 versus normal) and left ventricular end-diastolic dimension (LVED) was 0.97+/-0.98 (P<0.001 versus normal). The initial mean QT dispersion was 54+/-23 ms (P<0.001 versus normal). Mixed linear regression analysis for repeated measures demonstrated that the LVED Z-score decreased significantly over time, and a greater Z-score was independently associated with a greater initial LVED Z-score. Increased QT dispersion was only related to higher initial dispersion, with no trend over time.

CONCLUSIONS

While systolic ventricular dysfunction may not be evident, subclinical myocardial involvement may be indicated by subtle ventricular dilation and repolarization abnormalities.

Effectiveness of angiotensin-converting enzyme inhibitors in pediatric patients with mid to severe aortic valve regurgitation

The long-term benefit of angiotensin-converting enzyme inhibitors in pediatric patients with aortic valve regurgitation is under consideration. Eighteen patients with mid to severe aortic valve regurgitation were retrospectively evaluated. Echocardiographic parameters (left ventricular end-diastolic diameter, shortening fraction, left ventricular posterior wall thickness, and grade of aortic valve regurgitation) were analyzed before and during therapy with angiotensin-converting enzyme inhibitors. Data are given as standard deviation scores (Z-scores) derived from body surface-adjusted normal values. Median (interquartile range) age at start of therapy was 8.4 (5.4 to 10.0) years, and total follow-up 2.3 (0.9 to 5.4) years. Left ventricular end-diastolic diameter increased from 3.6 (2.3 to 4.5) to 3.7 (2.4 to 4.8), and left ventricular posterior wall diameter decreased from 1.9 (1.1 to 3.0) to 1.1 (0.5 to 2.3). Grade of aortic valve regurgitation increased from 3.5 (2.3 to 4.0) to 4.0 (2.0 to 4.0), and shortening fraction decreased from 39% (34% to 43%) to 37% (34% to 42%). No significant effect of angiotensin-converting enzyme inhibitors on left ventricular dimensions or function was found in our population of patients with mid to severe aortic valve regurgitation. Angiotensin-converting enzyme inhibitors may not alter left ventricular overload in pediatric patients with aortic valve regurgitation.

Regression equations for calculation of z scores of cardiac structures in a large cohort of healthy infants, children, and adolescents: an echocardiographic study

BACKGROUND

Decision making in the care of pediatric patients with congenital and acquired heart disease remains reliant on detailed measurements of cardiac structures using 2-dimensional echocardiography. Calculated z scores are often used to normalize these measurements to the patient's body size. Existing normal data in the literature are limited by small sample size, small numbers of measured cardiac structures, and inadequate data for the calculation of z scores. Accordingly, we sought to develop normative data in a large pediatric cohort using modern echocardiographic equipment from which z scores could be calculated.

METHODS

Two-dimensional and M-mode echocardiography was performed in 782 patients ranging in age from 1 day to 18 years. Measurements were made of 21 individual cardiac structures. Regression equations were derived to relate the size of the various cardiac structures to body surface area. Data are presented graphically, and regression equations are derived relating cardiac dimension to body surface area.

CONCLUSION

The presented data will allow the calculation of z scores for echocardiographically measured cardiac structures. This information will be valuable for clinicians caring for infants and children with known or suspected cardiac disease.

Cardiac manifestations of Anderson-Fabry disease in children and adolescents

AIM

Fabry disease (Fabry) is a rare X-linked disorder caused by a deficiency of the lysosomal enzyme alpha-galactosidase A. The progressive accumulation of the major substrate, globotriaosylceramide, leads to renal dysfunction and hypertrophic cardiomyopathy, which are reported to become apparent in the third decade. This study was performed to determine if signs of cardiac manifestations of Fabry are seen in younger Fabry patients.

METHODS

Twenty children and adolescents of <or=18 years of age with confirmed Fabry underwent a standard 12-lead electrocardiogram (ECG), a 2-h Holter ECG, blood pressure measurements and a two-dimensional echocardiogram. Follow-up examinations were conducted for 14 patients after a mean interval of 25.9 months.

RESULTS

At baseline, mean left ventricular mass (LVM) indexed to height (LVM/h(2.7)) was 45.0+/-2.3 and 47.0+/-3.4 g/m(2.7) in boys (n=8) and girls (n=12), respectively, and all patients had LVM/h(2.7) of >75th percentile of that in healthy controls. After a mean 26-month follow-up, 12 out of 14 patients (85.7%) showed a mean increase of 7.5+/-3.2 g/m(2.7) in LVM/h(2.7). Heart rate variability (HRV) analyses revealed that male, but not female, Fabry patients had significantly reduced HRV, reflecting a reduction in parasympathetic stimulation of the heart (p<0.05).

CONCLUSION

Cardiac involvement in children with Fabry is frequent and may progress even at young age.

Aortic Valvuloplasty in Pediatric Patients Substantially Postpones the Need for Aortic Valve Surgery

Background— Aortic valvuloplasty (AoVP) is an established procedure regarded as a valid alternative for surgical management of congenital aortic valve stenosis. However, its long-term efficacy in preventing or postponing aortic valve surgery remains uncertain for the individual patient. Therefore, the aim of this study was to study the long-term results of AoVP in pediatric patients and its efficacy in preventing or postponing aortic valve surgery.

Methods and Results— We reviewed up to 17.5 years of follow-up data of all 188 patients who received AoVP at the Deutsches Herzzentrum München. The patients were divided into those <1 month of age (group <1 month; n=68) and those ≥1 month of age (group ≥1 month; n=120) at the time of AoVP. After the first and second AoVP, moderate and severe aortic regurgitation developed in 29% and 14%, respectively, of the patients in group <1 month and in 19% and 29%, respectively, of the patients in group ≥1 month. Survival after 10 years free from aortic valve surgery was 59% (95% confidence interval, 45 to 73) in group <1 month and 70% (95% confidence interval, 59 to 81) in group ≥1 month.

Conclusions— This study shows that the long-term results of AoVP of congenital aortic valve stenosis in pediatric patients and its efficacy in preventing or postponing aortic valve surgery are very good. About two thirds of the patients are free from aortic valve surgery 10 years after AoVP.

Early versus late cord clamping: effects on peripheral blood flow and cardiac function in term infants

BACKGROUND

In the debate on the best cord clamping time in newborn infants, we hypothesized that late cord clamping enables an increased volemia due to blood transfer to the newborn from the placenta.

AIM

To assess whether clamping time can affect limb perfusion and heart hemodynamics in a group of 22 healthy term newborn infants.

STUDY DESIGN

A case-control study.

SUBJECTS

Eleven early-clamped (at 30 s) vaginally-delivered newborn infants were compared with eleven late-clamped (at 4 min) newborns.

OUTCOME MEASURES

The two groups were studied using near-infrared spectroscopy and M-mode echocardiography.

RESULTS

Late cord clamping coincided with a higher hematocrit (median 62% versus 54%) and hemoglobin concentration (median 17.2 versus 15 g/dL), whilst there were no changes in bilirubin level. Echocardiography showed a larger end-diastolic left ventricle diameter (1.7 cm median value versus 1.5) coupled with unvaried shortening and ejection fraction values. There were no changes in calf blood flow, oxygen delivery, oxygen consumption or fractional oxygen extraction calculated from the NIRS measurements, or in foot perfusion index.

CONCLUSIONS

Our results demonstrated that late cord clamping coincides with an increased placental transfusion, expressed by higher hematocrit and hemoglobin values, and larger left ventricle diameter at the end of the diastole, with no changes in peripheral perfusion or oxygen metabolism.

Noradrenaline for management of septic shock refractory to fluid loading and dopamine or dobutamine in full-term newborn infants

AIM

To determine the effects of noradrenaline in full-term newborns with refractory septic shock.

METHODS

Newborns of >35 weeks' gestation with persistent septic shock, despite adequate fluid resuscitation and high dose of dopamine/dobutamine were eligible. In this prospective observational study, we recorded respiratory and hemodynamic parameters prior to and 3 h after starting noradrenaline infusion.

RESULTS

Twenty-two newborns were included (gestational age [GA] 39 +/- 1.7 weeks, birth weight (BW) 3110 +/- 780 g). Before starting noradrenaline, the infants received a mean volume expansion of 31 +/- 15 mL/kg and a mean infusion rate of dopamine of 14 +/- 5 microg/kg/min or dobutamine of 12 +/- 6 microg/kg/min. Three hours after starting noradrenaline (rate 0.5 +/- 0.4 microg/kg/min), the mean arterial blood pressure rose from 36 +/- 5 to 51 +/- 7 mmHg (p < 0.001). Urine output increased from 1 +/- 0.5 to 1.7 +/- 0.4 mL/kg/h (p < 0.05). Blood lactate concentration decreased from 4.8 +/- 2.3 to 3.3 +/- 1.8 mmol/L (p < 0.01). Despite an initial correction of hypotension, four infants died later.

CONCLUSION

Noradrenaline was effective in increasing systemic blood pressure. An increase in urine output and a decrease in blood lactate concentration suggest that noradrenaline may have improved cardiac function and tissue perfusion.

Fetal growth restriction in preterm infants and cardiovascular function at five years of age

OBJECTIVES

We have previously reported an increased cardiac workload in newborn preterm small (SGA) infants, but not in infants appropriate for gestational age (AGA). We hypothesized that these cardiovascular changes will persist at follow-up at 5 years of age.

STUDY DESIGN

We assessed blood pressure, echocardiography, and skin perfusion with laser Doppler flowmetry in 22 SGA (821 +/- 248 g, 28.5 +/- 2.5 gestational weeks) and in 25 AGA (1065 +/- 241 g, 27.6 +/- 0.8 weeks) preterm children at age 5 years. Laser Doppler flowmetry also was used in 13 control children (3982 +/- 425 g, 40.4 +/- 1.8 weeks).

RESULTS

The preterm children in both the SGA and AGA groups had similar higher systolic blood pressures, increased interventricular septum thicknesses, and smaller left ventricular end-diastolic diameters compared with population reference values. Maximal endothelium-independent perfusion to sodium nitroprusside was higher and maximal endothelium-dependent perfusion to acetylcholine reached a plateau earlier in the AGA preterm group than in the control group.

CONCLUSIONS

Prematurity may impair cardiovascular function independently of intrauterine growth restriction. Altered cardiac dimensions and differences in perfusion responses may reflect increased cardiac afterload.

Noninvasive Evaluation of Late Anthracycline Cardiac Toxicity in Childhood Cancer Survivors

Purpose

Childhood cancer survivors treated with anthracyclines and cardiac radiation are at risk for late-onset cardiotoxicity. The purpose of this study was to delineate the relationship between clinical factors and abnormalities of noninvasive cardiac testing (NICT).

Patients and Methods

Participants were recruited from a long-term follow-up clinic. Study measures comprised physical examination, laboratory evaluation, echocardiogram, and ECG. Mean fractional shortening (FS) and afterload were compared for survivors who did (at risk [AR]) and did not (no risk [NR]) receive potentially cardiotoxic modalities, and with values expected for comparable age- and sex-matched controls.

Results

The 278 study participants (mean age, 18.1 years; median age, 16.8 years; range, 7.5 to 39.7 years) included 223 survivors AR for cardiotoxicity after treatment with anthracyclines (median dose ± standard deviation [SD], 202 ± 109 mg/m2) and/or cardiac radiation. Mean FS (± SD) was lower for AR (0.33 ± 0.06) compared with NR survivors (0.36 ± 0.05; P = .004) and normative controls (0.36 ± 0.04; P < .001). Mean afterload (± SD) was higher for AR (58 ± 21 g/cm2) compared with NR survivors (46 ± 15 g/cm2; P < .001) and normative controls (48 ± 13 g/cm2; P < .001). The distribution of FS and afterload among NR survivors did not differ from that of controls. After adjustment for age group at diagnosis and time since completion of therapy, anthracycline dose predicted decline in distribution of FS (P < .001) and increase in distribution of afterload (P < .001). Treatment with anthracycline doses ≥ 100 mg/m2 increased the risk of abnormal NICT; survivors who received ≥ 270 mg/m2 had a 4.5-fold excess risk of abnormal NICT (95% CI, 2.1 to 9.6) compared with controls.

Conclusion

Childhood cancer survivors treated with anthracycline doses ≥ 270 mg/m2 are at greatest risk for abnormalities of FS and afterload.

Hemodynamic improvement is faster after percutaneous ASD closure than after surgery

OBJECTIVES

Hemodynamic effects of surgical and percutaneous closure of atrial septal defect (ASD) were evaluated.

BACKGROUND

ASD causes volume overload of right ventricle (RV) and is associated with distortion and dysfunction of left ventricle (LV). The amount and timing of hemodynamic changes after ASD closure are not well known.

METHODS

The study group consisted of 7 children treated surgically and 17 treated in the catheterization laboratory. In the control group, there were 51 healthy children. RV size and LV end-diastolic and systolic dimensions, volumes, and function were examined by two- and three- dimensional echocardiography and serum concentrations of natriuretic peptides measured prior to ASD closure, and 1, 6, and 12 months thereafter.

RESULTS

In all children with ASD, during the 1-year follow-up, the z score of RV end-diastolic diameter decreased from a median 5.00 SD to 2.25 SD (P < 0.001). Dilatation of RV did not resolve entirely during 1-year follow-up in either treatment group. End-diastolic LV diameter increased from -1.50 to -0.50 SD (P < 0.001). LV size increased slower in the surgical subgroup but reached control levels in both groups. Concentrations of natriuretic peptides increased during the first month after ASD closure and normalized thereafter in patients treated percutaneously but remained higher than in controls in patients treated surgically.

CONCLUSIONS

During 1-year follow-up after ASD closure, RV size decreases but does not normalize in all patients. The size of the LV normalizes after ASD closure but the increase in LV size is slower in patients treated surgically. Serum levels of ANPN and proBNP are elevated prior to ASD closure but decrease thereafter to control levels in patients treated with the percutaneous technique but not in those treated surgically.

Reversal of tacrolimus-related hypertrophic cardiomyopathy after conversion to rapamycin in a pediatric liver transplant recipient

Tacrolimus (Tac)-related hypertrophic cardiomyopathy (HCM) has been reported to be an unusual but serious complication affecting pediatric patients after solid organ transplantation. Herein, we present a case of young liver transplant recipient with Tac-induced HCM, treated by discontinuation of Tac followed by conversion to rapamycin (Rap). Our case report points out the potential but rather low risk of HCM during Tac immunosuppression in pediatric liver transplants and demonstrates that replacement of calcineurin inhibitors with mammalian target of Rap (mTOR) inhibitors may be an efficacious therapeutic tool to effect regression of established cardiac hypertrophy.

Cardiac dysfunction in children with mulibrey nanism

Mulibrey nanism is an autosomal recessive disease with severe growth failure and multiple organ involvement. Heart manifestations include constrictive pericarditis and restrictive cardiomyopathy. The purpose of this study was to evaluate left ventricular (LV) diastolic and systolic function in children with mulibrey nanism utilizing two- and three- dimensional (2-D and 3-D) echocardiography and measurement of serum levels of natriuretic peptides. Of the 30 children diagnosed with mulibrey nanism in Finland, 26 participated. The control group comprised 26 children. In 2-D echocardiography, the interventricular septum and LV posterior wall were thicker in patients. The left atrium/aorta ratio measured a median 1.8 (range, 1.4-2.5) in patients and 1.3 (range, 1.0-1.7) in controls (p < 0.001). Patients differed from controls in several indices of diastolic LV function. In 3-D echocardiography, LV end diastolic volume measured a median of 51.9 ml/m(2) (range, 33.3-73.4) in patients and 59.7 ml/m(2) (range, 37.6-87.6) in controls (p = 0.040), and serum levels of N-terminal proatriopeptide and N-terminal pro-brain natriuretic peptide measured, respectively, a median of 0.54 nmol/L (range, 0.04-4.7) and 289 ng/L (range, 18-9170) in patients and 0.28 nmol/L (range, 0.09-0.72; p < 0.001) and 54 ng/L (range, 26-139; p < 0.001) in controls. They correlated with several indices of diastolic LV function. In a significant proportion of children with mulibrey nanism, myocardial function is impaired. Significant correlations appeared between indices of LV function, size of the left atrium, and levels of natriuretic peptides, showing that measurement of serum levels of natriuretic peptides is a useful follow-up method despite its dependence on loading conditions.

Severe transient cardiac failure caused by placental chorangiosis

BACKGROUND

Chorangiomas are villous capillary tumors of the placenta with high impact on neonatal morbidity and mortality. Cardiac complications have occasionally been reported.

OBJECTIVE

To elucidate clinical features, diagnosis and treatment of cardiac failure caused by chorangiomas.

METHOD

We report a case of a newborn, in whom massive chorangiomas were associated with severe cardiac failure, anemia, and thrombocytopenia.

RESULTS

Chorangiosis was not diagnosed prenatally. The pre-existing cardiac failure of the infant deteriorated soon after birth. Despite the severe stage, cardiac failure was reversible with intensive medical treatment including phosphodiesterase inhibitor. Complete recovery with no signs of cardiomyopathy was confirmed at the age of 5 months.

CONCLUSIONS

Severe cardiac failure in the neonate can be caused by chorangiosis. The time of diagnosis and treatment seems to be critical for the outcome of the infant. Prenatal treatment interventions should be considered.

Left ventricular segmental dysfunction following percutaneous transcatheter closure of a membranous ventricular septal defect

Percutaneous device closure of membranous ventricular septal defects is an attractive alternative for surgical treatment. A patient with left ventricular segmental dysfunction with infarct like ECG pattern following transcatheter membranous VSD closure is presented. Possible pathophysiological mechanisms of this phenomenon are discussed.

Cardiac findings after enzyme replacement therapy for mucopolysaccharidosis type I

Mucopolysaccharidosis type I is a lethal autosomal recessive storage disease caused by a deficiency of lysosomal alpha-L-iduronidase and the consequent systemic accumulation of glycosaminoglycan. Cardiomyopathy and valvar insufficiency occur as glycosaminoglycan accumulates in the myocardium, expands the spongiosa of cardiac valves, and proliferates within the myointima of the epicardial coronary arteries. Congestive heart failure and death occur within the first decade of life in the most severe cases. Allogeneic hematopoietic stem cell transplantation, used in severe forms of the disease, markedly prolongs survival, alleviates ventricular hypertrophy, and preserves cardiac function, but cardiac valves continue to thicken and valvular insufficiency progresses. Enzyme replacement therapy with human recombinant alpha-L-iduronidase has been proposed as an alternativee therapy for patients with mucopolysaccharidosis type I in whom the risk/benefit ratio of hematopoietic stem cell transplantation seems unfavorable. The investigators report the cardiac findings in a small series of 5 children with mucopolysaccharidosis type I who received enzyme replacement therapy for as long as 7 years. No deaths occurred during treatment. Left ventricular hypertrophy, which was present before therapy, resolved in all cases, and myocardial function remained normal. In contrast, the mitral and aortic valves remained thickened and, in some instances, developed progressive thickening and regurgitation. In conclusion, long-term enzyme replacement therapy has some clear benefits for the myocardium, but the cardiac valves appear unresponsive, and the ultimate effect on the coronary vasculature is unknown.

Resting and exercise cardiorespiratory function in survivors of congenital diaphragmatic hernia

Our objective was to study exercise capacity and cardiorespiratory response to exertion in survivors of congenital diaphragmatic hernia (CDH). This was a cross-sectional cohort study of 23 CDH survivors, aged 10-16 years, and 23 gender- and age-matched controls. Exercise testing was performed on a cycle ergometer, with cardiac output measurements made using exponential CO2 rebreathing. Pretest cardiorespiratory assessment was done by echocardiography and pulmonary function testing. Statistical analysis was performed using Student's t-test, regression analysis, and longitudinal model computing with spatial covariance structure. No echocardiographic evidence for pulmonary hypertension was found at rest (right ventricular systolic pressures, 27 +/- 6 mmHg). Mean pulmonary artery diameter on the side of the CDH was significantly smaller than contralaterally, but was within normal range (z-score, 0 +/- 1.1 vs. 1.2 +/- 1.6, P < 0.01). Exercise capacity was mildly reduced in CDH compared to controls and predictive data (maximum workload, 77% +/- 12% vs. 91% +/- 16% of predicted, P < 0.01). Cardiorespiratory response to exertion was not significantly different between groups. In conclusion, most adolescent CDH survivors have nearly normal exercise capacity and cardiorespiratory response to exertion. This study may prove useful in comparisons with future cohorts comprising more severely affected individuals now surviving due to improved neonatal care.

Cardiopulmonary Pathology Among Children Resident at High Altitude in Tintaya, Peru: A Cross-Sectional Study

Symptomatic high-altitude pulmonary hypertension and structural cardiac abnormalities related to high altitude have been reported previously. However, their true prevalence has not been systematically determined. We assessed clinical indicators of cardiovascular health or disease and correlated them with anatomic and physiologic cardiovascular features in preschool and schoolchildren living at 4000 m. We also estimated the prevalence of cardiovascular problems in the population, with emphasis on symptomatic high altitude pulmonary hypertension and structural cardiopathies. Three hundred and twenty-six children residents of Tintaya, Peru, were cross-sectionally studied. Methods included structured interviews, anthropometry and physical examination, arterial oxygen saturation, hemoglobin determination, electrocardiography, and echocardiography. The prevalence of structural cardiac problems was 1.5%, with less than 1% possibly attributable to high altitude. All children with structural cardiac abnormalities were identified by a focused physical exam prior to echocardiography. None were identified by the health interview. No symptomatic high altitude pulmonary hypertension was identified in the absence of underlying structural anomalies. The prevalence of structural cardiac problems was consistent with data from sea level. Active monitoring of the health status of a pediatric population at high altitude is valuable in the timely detection of cardiac abnormalities. Although our study children enjoyed generally excellent health, comparative, longitudinal studies are warranted to determine the incidence of high altitude cardiopulmonary problems and to identify risk factors and early markers for later disorders associated to life at high altitude. Our findings are applicable to children with some degree of high altitude genetic background and high mobility patterns to lower altitudes and living in comparatively good nutritional and socioeconomic conditions.

Arterial and cardiac disease in young adults with childhood-onset end-stage renal disease—impact of calcium and vitamin D therapy

BACKGROUND

Studies in patients with childhood-onset end-stage renal disease (ESRD) provide a diagnostic window to the evolution of cardiovascular disease (CVD) in this population. Hyperphosphataemia and renal osteodystrophy are particularly difficult to treat in paediatric patients, but there is only limited information regarding the effect of calcium-containing phosphate binders and vitamin D preparations on the development of CVD in the young.

METHODS

We studied 40 adult patients (mean age 23.6 years) who developed ESRD at the age of 11.5 +/- 4 years and 40 matched healthy control subjects. Nine patients were on dialysis and 31 had a functioning kidney transplant. Measurements included intima-media thickness (IMT) of the common carotid artery, electron beam computed tomography (EBCT) for the detection of coronary artery calcifications (CAC), echocardiography and post-ischaemic arterial blood flow by venous occlusion plethysmography. Patient characteristics, atherosclerotic risk factors and a complete account of prescribed medications were analysed for correlations with arterial and cardiac changes.

RESULTS

The IMT was not significantly different in patients and controls; four patients (10%) had coronary calcifications on EBCT. Twenty-five patients (62.5%) had left ventricular hypertrophy. Patients had a 40% reduction of post-ischaemic arterial flow. Morphological alterations of the heart and arteries were significantly correlated with the duration of ESRD and dialysis time, and with the cumulative intake of calcium-containing phosphate binders and active vitamin D preparations. Functional changes (vascular reactivity) were correlated with duration of ESRD and non-traditional risk factors.

CONCLUSIONS

Young adults with ESRD since childhood have systemic CVD characterized by a decrease in arterial elasticity, the occurrence of CAC and changes in left ventricular morphology. Treatment with calcium-containing phosphate binders and active vitamin D preparations is independently associated in a dose-dependent manner with surrogate markers for CVD.

The Influence of Percutaneous Closure of Patent Ductus Arteriosus on Left Ventricular Size and Function

OBJECTIVES

We aimed to evaluate the effect of percutaneous closure of patent ductus arteriosus (PDA) on left ventricular (LV) hemodynamics.

BACKGROUND

Today, most PDAs are closed percutaneously. Little is known, however, about hemodynamic changes after the procedure.

METHODS

Of 37 children (ages 0.6 to 10.6 years) taken to the catheterization laboratory for percutaneous PDA closure, the PDA was closed in 33. Left ventricular diastolic and systolic dimensions, volumes, and function were examined by two-dimensional (2D) and three-dimensional (3D) echocardiography and serum concentrations of natriuretic peptides measured before PDA closure, on the following day, and 6 months thereafter. Control subjects comprised 36 healthy children of comparable ages.

RESULTS

At baseline, LV diastolic diameter measured >+2 SD in 5 of 33 patients. In 3D echocardiography, a median LV diastolic volume measured 54.0 ml/m2 in the control subjects and 58.4 ml/m2 (p < 0.05) in the PDA group before closure and 57.2 ml/m2 (p = NS) 6 months after closure. A median N-terminal brain natriuretic peptide (pro-BNP) concentration measured 72 ng/l in the control group and 141 ng/l in the PDA group before closure (p = 0.001) and 78.5 ng/l (p = NS) 6 months after closure. Patients differed from control subjects in indices of LV systolic and diastolic function at baseline. By the end of follow-up, all these differences had disappeared. Even in the subgroup of patients with normal-sized LV at baseline, the LV diastolic volume decreased significantly during follow-up.

CONCLUSIONS

Changes in LV volume and function caused by PDA disappear by 6 months after percutaneous closure. Even the children with normal-sized LV benefit from the procedure.

Diastolic dysfunction without left ventricular hypertrophy is an early finding in children with hypertrophic cardiomyopathy-causing mutations in the beta-myosin heavy chain, alpha-tropomyosin, and myosin-binding protein C genes

OBJECTIVES

We investigated the presence of left ventricular hypertrophy (LVH) and features of diastolic dysfunction in genotype-confirmed children from families with hypertrophic cardiomyopathy (HCM) and healthy control children.

BACKGROUND

In subjects with HCM-causing mutations, LVH usually does not evolve until adolescence. Diastolic dysfunction has not been systematically evaluated in children carrying HCM-causing mutations.

METHODS

All children (aged 1.5-16.7 years) from 14 HCM families with identified disease-causing mutations (the Arg719Trp mutation in the beta-myosin heavy chain gene [MYH7], the Asp175Asn mutation in the alpha-tropomyosin gene [TPM1], the Gln1061X mutation in the myosin-binding protein C gene [MYBPC3], and the IVS5-2A-->C mutation in the MYBPC3 gene) and 53 matched control children were examined with electrocardiography and 2- and 3-dimensional echocardiography (2DE and 3DE). Natriuretic peptides were measured in children from HCM families and 67 control children.

RESULTS

Of 53 children from HCM families, 27 (51%) had a disease-causing mutation (G+). G+ children had slightly thicker septum on 2DE compared with the control children (P = .004), but only 3 (11%) of 27 G+ children exceeded the 95th percentile values of the body surface area-adjusted maximal LV thickness of healthy children (the major echocardiographic criterion for HCM). However, prolonged isovolumetric relaxation time, increased left atrial volume on 3DE, or increased levels of NT-proANP, all features suggestive of diastolic dysfunction, were found in 14 (52%) of 27 G+ children.

CONCLUSIONS

In children with HCM-causing mutations, signs of diastolic dysfunction are found in about half of the cases, as LVH is present only in small percentage of these children.

Impaired left ventricular systolic function early after heart transplantation is associated with cardiac allograft vasculopathy

Cardiac allograft vasculopathy (CAV) is a major cause of death more than 1 year after heart transplantation. We evaluated the role and possible predictive value of different etiological factors on development of CAV as diagnosed by quantitative coronary angiography (QCA). A total of 121 patients were studied with baseline QCA and 117 had a follow-up study at 1 year to assess the relationship of mean lumen diameter loss (MLDL) in main coronary arteries to immunological and non-immunological factors potentially affecting long-term survival. Out of them, 103 patients were males (85%), 114 (94%) patients were Caucasians and mean age was 48.5 +/- 10 years. Univariate analysis showed that MLDL at 1 year was inversely related to echocardiographic fractional shortening (FS) measured within the first week after transplantation (p = 0.0098) and to intracranial hemorrhage as cause of donor death (p = 0.04) and was directly related to male donors (p = 0.0008), domino transplants (p = 0.037) and donor negative cytomegalovirus (CMV) status (p = 0.022). Multivariate analysis showed that initial FS (p = 0.006) and donor intracranial hemorrhage as a cause of death (p = 0.042) were inversely related to MLDL whereas donor male sex (p = 0.003) and prednisolone treatment throughout the first year (p = 0.012) were directly related. Thus, left ventricular systolic dysfunction early after heart transplantation was associated with subsequent development of CAV.

Cardiovascular findings in very low birthweight schoolchildren with and without bronchopulmonary dysplasia

BACKGROUND

With the introduction of new therapies in peri- and neonatology, the clinical picture of bronchopulmonary dysplasia (BPD) seems to alter. The consequences of this "new BPD" are of interest.

AIM

To evaluate cardiovascular findings during the surfactant era in very low birthweight (VLBW, birth weight < 1500 g) schoolchildren with and without BPD.

METHODS

At 7-8 years of age, 34 VLBW children with BPD born in one hospital underwent blood pressure (BP) measurement, electrocardiography (ECG), two-dimensional Doppler and M-mode echocardiography, flow-volume spirometry and whole-body plethysmography. The age- and sex-matched control groups comprised 34 VLBW children without BPD (no-BPD group) and 34 term children (term group).

RESULTS

The mean(SD) diastolic BP was significantly higher in the no-BPD than in the BPD group (65(9) vs. 59(8) mm Hg, p < 0.05). No clinically significant tricuspid regurgitations were found. The groups did not differ with respect to right ventricular systolic time intervals corrected for heart rate. The results of all M-mode measurements were within normal range. Compared to term controls, the BPD cases had lower mean(SD) forced expiratory flow in 1 s (90(14)% vs. 99(11)% of ref., p < 0.05) and more often high ratio of residual volume to total lung capacity (15(52%) vs. 4(13%), p < 0.01). No clinically significant correlations were found between current lung function and echocardiographic findings.

CONCLUSION

In the surfactant era, school-aged VLBW survivors with and without BPD do not seem to evince indirect signs of elevated pulmonary pressure. The increased pulmonary vascular resistance associated with BPD appears to resolve with time more rapidly than abnormalities in respiratory function.

Long term cardiac follow up of severe twin to twin transfusion syndrome after intrauterine laser coagulation

OBJECTIVE

To assess long term changes in cardiac morphology and function in survivors of severe twin to twin transfusion syndrome (TTTS) after intrauterine laser coagulation of placental anastomoses.

DESIGN

Prospective follow up of fetuses with severe TTTS treated by laser coagulation of intrauterine placental anastomoses. Fetal echocardiography and Doppler studies of feto-placental haemodynamic function were performed at the time of laser coagulation (median gestational age of 21.7 weeks). Postnatal cardiac follow up included a detailed echocardiographic study of systolic and diastolic cardiac function at a median age of 21.1 months.

SETTING

Paediatric cardiology unit.

PATIENTS

89 survivors from 73 consecutive pregnancies with severe TTTS.

RESULTS

Before laser treatment, 28 of 51 (54.9%) recipient twins had typical signs of cardiac dysfunction due to volume overload and 9 of 38 (23.7%) donors had absent or reversed end diastolic flow in the umbilical artery. Echocardiography was normal in 87.6% of the survivors (34 of 38 donors, 44 of 51 recipients). The prevalence of congenital heart disease and particularly of pulmonary stenosis, which was recorded only in recipients, was increased in comparison with the general population (congenital heart disease, 10 of 89 (11.2%) v 0.3%; pulmonary stenosis, 4 of 51 (7.8%) v 0.03%). Findings before laser treatment were not correlated with the development of structural heart disease.

CONCLUSIONS

Despite the high rate and severity of prenatal cardiac overload in recipients, the majority of cases of TTTS are normalised after laser treatment. However, given the increased prevalence of congenital heart disease and in particular pulmonary stenosis, intrauterine and postnatal follow up is warranted.

Pediatric Fabry disease

BACKGROUND

Fabry disease is an underdiagnosed, treatable, X-linked, multisystem disorder.

OBJECTIVES

To test the hypothesis that quality of life and sweating are decreased among pediatric patients with Fabry disease, compared with control subjects, and to provide quantitative natural history data and novel clinical end points for therapeutic trials.

DESIGN

Prospective, cross-sectional, observational study.

SETTING

Referral to the National Institutes of Health.

PARTICIPANTS

Twenty-five male children with Fabry disease (mean age: 12.3 +/- 3.5 years) and 21 age-matched control subjects.

MAIN OUTCOME MEASURES

Quality of life (measured with the Child Health Questionnaire) and sweating (assessed with the quantitative sudomotor axon reflex test).

RESULTS

Quality of life scores for pediatric patients <10 years of age with Fabry disease, compared with published normative values, were 55 +/- 17 vs 83 +/- 19 for bodily pain and 62 +/- 19 vs 80 +/- 13 for mental health. Bodily pain scores for patients > or =10 years of age were 54 +/- 22 vs 74 +/- 23. Sweat volume in the Fabry disease group was 0.41 +/- 0.46 microL/mm2, compared with 0.65 +/- 0.44 microL/mm2 in the control group. Renal function, urinary protein excretion, and cardiac function and structure were normal for the majority of patients. The 3 patients with residual alpha-galactosidase A activity > or =1.5% of normal values were free of cornea verticillata and had normal serum and urinary globotriaosylceramide levels. All other children had glycolipid levels comparable to those of adult patients with Fabry disease. Acroparesthesia and cardiac abnormalities were generally present before anhidrosis and proteinuria. Mapping of the missense mutations on the crystallographic structure of alpha-galactosidase A revealed that the mutations were partially surface-exposed and distal to the active site among individuals with residual enzyme activity. Mutations associated with left ventricular hypertrophy (defined as left ventricular mass index of >51 g/m2.7) were localized near the catalytic site of the enzyme.

CONCLUSIONS

Despite the absence of major organ dysfunction, Fabry disease demonstrates significant morbidity already in childhood. We have identified important, potentially correctable or preventable, outcome measures for future therapeutic trials. Prevention of complications involving major organs should be the goal for long-term specific therapy.

Echocardiographic and electrocardiographic findings of cardiomyopathy in Duchenne and Becker-Kiener muscular dystrophies

We assessed the cardiac findings in Duchenne muscular dystrophy (DMD) and Becker-Kiener muscular dystrophy (BMD) patients in the large outpatient group of our single-center institution. The analysis included the revision of patient records (retrospectively) and current echocardiography, electrocardiogram (ECG), and Holter ECG data (prospectively). Reduced left ventricular fraction shortening (FS) < 25% was found in 24% of all patients (50 DMD, 12.1 +/- 4.7 years: 20 BMD, 17.1 +/- 8.5 years). Median age of onset of FS < 25% was 16.8 +/- 1.0 in DMD and 30.4 +/- 3.4 in BMD; (p < 0.05). Holter ECG in DMD demonstrated sinus tachycardia in 26% deprivation of circadian rhythm in 31%, and reduced heart rate variability in 51%. For these reasons, we recommend carrying out echocardiography annually in DMD and BMD > 10 years. Because the rate of disturbances in the cardiac autonomic nervous system is high in DMD, we also recommend Holter ECG annually. Further investigation should be conducted to determine if treatment with ss-blockers and ACE inhibitors in combination reduces cardiac autonomic nervous imbalance, thus improving patient outcome in DMD.

Cardiac troponin T: a marker in the diagnosis of acute myocarditis in children

This study was conducted to assess the use of serum cardiac troponin T (cTnT) level as a noninvasive indicator to diagnose acute myocarditis in children. Noninvasive conventional methods often fail to diagnose myocarditis, A median cTnT level of 0.088 ng/ml (0.04-3.11) was reported in pediatric patients with acute myocarditis in our previous study. Hence, we attempted to determine the cutfoff level of cTnT to diagnose acute myocarditis in children. Pediatric patients with clinically suspected myocarditis or dilated cardiomyopathy (DCM) and a control group were recruited. History, physical examination, elctrocardiogram, chest roentgenogram, echocardiogram, cTnT level, and/or endomyocardial biopsy and clinical course were studied. The gold standard to diagnose acute myocarditis was endomyocardial biopsy proved according to the Dallas criteria and/or recovery from cardiovascular problems within 6 months of follow-up. Forty-three patients were admitted due to cardiovascular problems from primary myocardial dysfunction. Twenty-four patients were diagnosed as acute myocarditis (group 1), 19 were idiopathic chronic DCM (group 2), and 21 patients had moderate to large ventricular septal defect and congestive heart failure (group 3). Median cTnT level was statistically higher in (group 1) compared to groups 2 and 3. Ejection fraction (EF) and left ventricular end diastolic dimension (LVEDd) z score of acute myocarditis were 38.5% (range, 21-67) and 1.3 (range, -0.8-3.0), respectively, which were significantly better than DCM [28.0% (range, 17-45) and 6.0 (range, 2.0-10.0)]. The cutoff point of cTnT level to diagnose acute myocarditis was 0.052 ng/ml (sensitivity, 71%; specificity, 86%). cTnT level, EF, and LVEDd z score did not predict short-term outcomes of patients. In acute myocarditis, cTnT level and EF were significantly higher and LVEDd z score was significantly lower than in DCM. However, the three parameters had no significant effect on outcomes of the patients. Our data show that cardiac a cTnT level of 0.052 ng/ml is an appropriate cutoff point for the diagnosis of acute myocarditis.

Safety and efficacy of recombinant acid alpha-glucosidase (rhGAA) in patients with classical infantile Pompe disease: results of a phase II clinical trial

Pompe disease is an autosomal recessive muscle-wasting disorder caused by the deficiency of the lysosomal enzyme acid alpha-glucosidase. Due to virtual absence of acid alpha-glucosidase, patients with classical infantile Pompe disease develop progressive cardiomyopathy, skeletal muscle weakness and respiratory insufficiency leading to death in early infancy. We report on the results of a phase II clinical trial including two patients with classical infantile Pompe disease receiving enzyme replacement therapy over a period of 48 weeks by weekly infusions. Recombinant acid alpha-glucosidase was derived from the milk of transgenic rabbits. Safety was evaluated by recording adverse events while clinical efficacy was evaluated by ventilator-free survival, left ventricular mass index, motor development as well as histologic and biochemical analysis of muscle biopsies. This therapy was in general well-tolerated. There was an overall improvement in left ventricular mass, cardiac function, skeletal muscle function and histological appearance of skeletal muscle.

Cross-sectional study of echocardiographic characteristics in healthy children living at high altitude

Non-echocardiographic studies in healthy high altitude children have shown right ventricle predominance during infancy and childhood, associated to asymptomatic pulmonary hypertension and an increased pulmonary artery pressure. Systematic studies on echocardiography in such children have not been performed. In a cross-sectional study, we measured right and left heart morphologic and functional parameters, through M-mode, two-dimensional Doppler, and color Doppler echocardiographies, in a population of 321 healthy children ranging in age from 2 months to 19 years and living at high altitude (Tintaya, Peru, 4,100 m). Structured ad-hoc interviews were done to obtain information on medical history, patterns of exposure to high altitude of children and their parents and grandparents, place and altitude of pregnancy and birth, and housing conditions. A complete physical examination was performed before echocardiography. Hemoglobin concentration, pulse oximetry, and anthropometry were measured in all participating children. The right and left heart morphologic and functional echocardiographic measurements expressed by age and by body surface area were generally similar to sea-level reference populations. They were not consistently influenced by sex, nutritional status, chest dimensions, pulse oximetry, hemoglobin concentration, ethnicity, length of residence at high altitude, or parental history of exposure to high altitude. Most children had at least some degree of high-altitude ancestry as assessed by ethnicity and history of parental exposure to altitude. The cardiovascular development at high altitude in children with some degree of high-altitude ancestry seems to follow a pattern similar to sea-level children. The results can be used as reference values to interpret individual echocardiographic studies in comparable children living in similar settings.

Echocardiographic findings in the PANDAS subgroup

BACKGROUND

Sydenham's chorea is the neurologic manifestation of rheumatic fever and is a diagnosis of exclusion requiring only the presence of frank chorea in the absence of another neurologic disorder. Two thirds of children with Sydenham's chorea also have rheumatic carditis (pathologic mitral valve regurgitation). Although there are similar neuropsychiatric symptoms and preceding group A beta-hemolytic streptococcal infection associated with both Sydenham's chorea and the PANDAS (pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections) subgroup, it is unknown whether patients in the PANDAS subgroup have any cardiac involvement.

METHODS

Sixty children meeting the criteria for PANDAS were entered into protocols at National Institute of Mental Health between 1993 and 2002. Doppler and 2-dimensional echocardiograms were performed on these subjects to assess valvular heart disease.

RESULTS

Of these 60 children, no echocardiographic evidence of significant mitral or aortic valve regurgitation was found. One patient was found to have mild mitral regurgitation, and all patients had normal left atrial size and normal left ventricular size and function. Follow-up echocardiograms on 20 children showed no significant valvular regurgitation.

CONCLUSION

The evidence of a clear lack of rheumatic carditis in these children supports the hypothesis that PANDAS is a distinct neuropsychiatric diagnosis separate from Sydenham's chorea.

Cardiopulmonary fitness and muscle strength in patients with osteogenesis imperfecta type I

OBJECTIVE

To evaluate cardiopulmonary function, muscle strength, and cardiopulmonary fitness (VO 2 peak) in patients with osteogenesis imperfecta (OI).

STUDY DESIGN

In 17 patients with OI type I (mean age 13.3 +/- 3.9 years) cardiopulmonary function was assessed at rest using spirometry, plethysmography, electrocardiography, and echocardiography. Exercise capacity was measured using a maximal exercise test on a bicycle ergometer and an expired gas analysis system. Muscle strength in shoulder abductors, hip flexors, ankle dorsal flexor, and grip strength were measured. All results were compared with reference values.

RESULTS

Cardiopulmonary function at rest was within normal ranges, but when it was compared with normal height for age and sex, vital capacities were reduced. Mean absolute and relative VO 2 peak were respectively -1.17 (+/- 0.67) and -1.41 (+/- 1.52) standard deviations lower compared with reference values ( P < .01). Muscle strength also was significantly reduced in patients with OI, ranging from -1.24 +/- 1.40 to -2.88 +/- 2.67 standard deviations lower compared with reference values.

CONCLUSIONS

In patients with OI type I, no pulmonary or cardiac abnormalities at rest were found. The exercise tolerance and muscle strength were significantly reduced in patients with OI, which might account for their increased levels of fatigue during activities of daily living.

Predictors of outcome of myocarditis

Heart failure from myocarditis may be transient or may progress to unremitting severe cardiac failure. This study was performed to determine the outcomes and prognostic features of pediatric patients with myocarditis. Patients with the diagnosis of myocarditis between 1990 and 2001 were identified through the coding system of Yale-New Haven Hospital. A total of 28 patients were included, with ages ranging from 1 day to 20 years. Before discharge, 11 patients developed unremitting severe cardiac failure. Of the remaining 17 patients, at the time of discharge 10 had normal systolic function and 7 had decreased systolic function. Unremitting cardiac failure developed in 9 of 14 patients (64%) with an ejection fraction < 30% and in only 2 of 14 (14%) of those with an ejection fraction > or = 30% on admission (p < 0.01). Furthermore, shortening fraction < 15%, left ventricular dilatation, and moderate to severe mitral regurgitation on admission as well as arrhythmia were significantly associated with development of unremitting severe cardiac failure. In this series of patients with myocarditis, by the time of discharge 39% of the patients had developed unremitting severe cardiac failure, 25% had depressed systolic function, and 36% had normal systolic function. Predictive factors at admission for poor outcome were ejection fraction < 30%, shortening fraction < 15%, left ventricular dilatation, and moderate to severe mitral regurgitation.

Estimates of interventricular septum thickness are markedly affected by the method used

Modern echocardiographic techniques allow precise measurements of interventricular septum thickness by two-dimensional echocardiography (2DE) and M-mode echocardiography. The advantage of 2DE is the more accurate estimate in cases in which the shape of the septum differs from normal. However, the usefulness of measurements by 2DE is limited due to the lack of reference values. We measured maximal septum thickness by 2DE in 168 healthy subjects aged 2 to 27 years and compared the results to those obtained by M-mode. In agreement analysis the bias +/- 2 SD between 2DE and M-mode was 0.8 +/- 1.7 mm (p <0.001). Maximal septum thickness exceeded the upper normal limit (+2 SD) of the largest pediatric reference data in 14 (8%) of the healthy subjects studied. Interventricular septum thickness is greater when measured by 2DE than by M-mode. Previous M-mode reference values should be used with caution; preferably, reference data based on 2DE should be used.

Echocardiographic parameters in adolescents with sleep-related breathing disorders

Few data are known about the effects of sleep-related breathing disorders (SRBD) on the cardiovascular system in adolescents. Forty healthy adolescents (mean age, 13.7 +/- 1.6 years) answered a questionnaire regarding symptoms of sleep-related breathing disorders (SRBD) and underwent a cardiorespiratory polygraphy and echocardiography. Echocardiographic data in snorers with polygraphic abnormalities suggestive of SRBD (positive group, n = 29) were compared with the results in nonsnorers without polygraphic abnormalities (n = 11) who were included in the control group. Ventricular dimensions and indices of left ventricular systolic function were within normal limits and were not significantly different between the two groups. Indices of left ventricular diastolic function were also within normal limits, but isovolumetric relaxation time (IVRT) was significantly longer among the positive group (72.5 +/- 8.4 msec) than among the controls (65.1 +/- 7.9 msec) (P = 0.018). Multiple regression analysis showed that posterior wall thickness was predicted by a model that included cardiac events related with respiratory events and/or desaturations, and respiratory disturbance index (RDI) in supine position. Deceleration of early diastolic flow was predicted by RDI, percentage of total recording time with SaO(2) < 90% (CT(90)), and age; the variability of isovolumetric relaxation time was predicted by a model that included RDI in supine position. We found a significant relationship between polygraphic parameters suggestive of SRBD and echocardiographic measurements of ventricular dimensions and diastolic function. Also, echocardiographic parameters suggestive of some degree of left ventricular diastolic dysfunction were found in snoring adolescents with polygraphic abnormalities.

Electrocardiographic signs of hypertrophy in fabry disease-associated hypertrophic cardiomyopathy

AIMS

Fabry disease results from deficient activity of the lysosomal enzyme alpha-galactosidase A. Progressive accumulation of the major substrates leads, in both men and women, to progressive hypertrophic cardiomyopathy. We aimed to evaluate the utility of different electrocardiographic (ECG) parameters for assessing the degree and severity of hypertrophic cardiomyopathy in patients with Fabry disease.

METHODS

A total of 166 ECGs of 94 hemi- and heterozygous patients with Fabry disease were analysed and compared with echocardiographic-estimated left ventricular mass (LVM).

RESULTS

There was a significant (p < 0.0001) correlation between QRS duration (R2 = 0.59), 12-lead amplitude/duration product (R2 = 0.61), Sokolow-Lyon voltage/duration product (R2 = 0.52) and LVM. Analysis of receiver operating characteristics revealed that the 12-lead amplitude/duration product had the highest sensitivity-specificity relationship (p < 0.01 compared with the Cornell index).

CONCLUSION

In general, ECG signs of left ventricular hypertrophy correlated well with LVM as revealed by echocardiography. Of the parameters studied, the 12-lead amplitude/duration product was the most successful at describing the severity of cardiac involvement in Fabry disease. These data suggest that ECG parameters have potential for use as a simple and cost-effective means of screening for hypertrophic cardiomyopathy in patients with Fabry disease.

Cardiac manifestations of Anderson-Fabry disease in heterozygous females

OBJECTIVES

We sought to define the prevalence of cardiac involvement in female patients with Anderson-Fabry disease (AFD).

BACKGROUND

Anderson-Fabry disease is a rare inborn X-linked lysosomal storage disorder. Globotriaosylceramide (Gb(3)), the major substrate of the deficient alpha-galactosidase A enzyme, accumulates progressively in vulnerable cells, including the cardiovascular system. It has been believed that heterozygous females have less cardiac involvement than hemizygous males with AFD.

METHODS

We performed two-dimensional echocardiographic examinations of female patients heterozygous for AFD.

RESULTS

Since 1997, a total of 55 female patients (mean age, 39.6 years; range, 6.1 to 70.8 years) with proven AFD have been investigated prospectively at our hospital. Of these, 13 (23.6%) had normal left ventricular (LV) geometry and LV mass (LVM). Seven patients (12.7%) had concentric remodeling, 29 patients (52.7%) concentric LV hypertrophy (LVH), and 6 patients (10.9%) eccentric LVH (2 with subaortic pressure gradients). There was a strong correlation between age and the severity of LVH (r(2) = 0.905; p < 0.0001), and all patients older than 45 years had LVH. With increasing LVM, there was a significant age-independent decrease in systolic and diastolic LV function. Mild thickening of the aortic valve leaflets was present in 25.5% of patients, with the same percentage demonstrating mild thickening of the mitral valve leaflets. Mild mitral valve prolapse was documented in 10.9% of patients.

CONCLUSIONS

Cardiac involvement, with LVH and structural valve abnormalities, is very common and worsens with age in females who are heterozygous for AFD, and they should therefore be considered candidates for enzyme replacement therapy.

Cardiovascular hemodynamics and exercise tolerance in thyroid disease

The heart is an organ sensitive to the action of thyroid hormone, and measurable changes in cardiovascular performance are detected with small variations in thyroid hormone serum concentrations. Most patients with thyroid disease experience cardiovascular manifestations, and the most serious complications of thyroid dysfunction occur as a result of cardiac involvement. The increased metabolic state and oxygen consumption that occur in hyperthyroid patients require an increased supply of oxygen and removal of metabolic products from the periphery. This is accomplished by increasing the cardiac output to meet the needs of the periphery. Circulation time is decreased in hyperthyroid patients, and a lowered arterial resistance and increased venous resistance promote the return of blood to the heart. Thyroid hormones may significantly decrease the strength of respiratory and skeletal muscles and affect regulatory mechanisms of adaptation to incremental effort. In hyperthyroidism, cardiovascular exercise testing and analysis of respiratory gas exchange demonstrate low efficiency of cardiopulmonary function as well as impaired chronotropic, contractile, and vasodilatatory reserves, which are reversible when euthyroidism is restored. During exercise, the increment (delta) of minute ventilation (respiratory rate x tidal volume), and oxygen pulse (oxygen uptake per heart beat) are significantly lower in dysthyroidism versus euthyroidism. Especially in older patients with thyroid dysfunction, markedly reduced workload, delta ejection fraction, and delta heart rate, both at the anaerobic threshold as well as at maximal exercise, are observed. In thyrotoxicosis, mitochondria oxidative dysfunction during exercise mostly causes intracellular acidosis, whereas in hypothyroidism, inadequate cardiovascular support appears to be one of the principal factors involved. These abnormalities partly explain why subjects with dysthyroidism are intolerant to exertion. Thus, in thyroid disease, both cardiac structures and function may remain normal at rest, however impaired cardiovascular and respiratory adaptation to effort becomes unmasked during exercise.

Cardiac involvement in thyroid hormone resistance

To analyze the cardiovascular alterations thought to occur in resistance to thyroid hormone (RTH), cardiac involvement in 54 patients with RTH was investigated with the help of two-dimensional and Doppler echocardiography. Data from 41 of 54 adult subjects with RTH were also compared with those of 24 and 20 cases with hyperthyroidism (H) and hypothyroidism (h), respectively, as well as 22 healthy euthyroid controls (C). With respect to the type of mutations, no correlation was found between cardiovascular features and genotype. Compared with affected adults, children with RTH showed markedly higher serum free T3 (FT3), free T4 (FT4), and baseline TSH concentrations. Compared with healthy children of comparable age, RTH children had significantly higher heart rate and lower left ventricular (LV) ejection fraction (P = 0.006). Also, higher heart rate and FT4 as well as shorter diastolic relaxation of the myocardium (all P = 0.001) between RTH subjects with and without thyrotoxic cardiovascular features were found. Cardiac symptoms (palpitations, 32% vs. 71%) and signs (sinus tachycardia, 26% vs. 79%; atrial fibrillation, 6% vs. 17%) were significantly less frequent in RTH vs. H (all P = 0.001). Compared with C and h, heart rate, cardiac output, stroke volume, and systolic aortic flow velocity were strongly increased in RTH (all P = 0.0001) and H, although ejection (P = 0.0012) and shortening (P = 0.0001) fractions of the LV were markedly lower in RTH vs. H. Diastolic parameters, such as isovolumic relaxation (P = 0.0001) and deceleration time (P = 0.013), were shorter in RTH vs. h and C. In RTH, positive correlations between FT3 and heart rate, and between FT4 and LV ejection fraction were observed, whereas negative correlations between both FT3 and FT4 and isovolumic relaxation were noted. In conclusion, these findings indicate a modulated hyperthyroid effect on cardiac systolic and diastolic function of the myocardium in RTH, whereas other parameters, such as ejection and shortening fractions of the LV, systolic diameter, and LV wall thickness, were comparable to C. Differences in term of cardiovascular changes were smaller between the RTH and C groups than the RTH and the H or h groups. Thus, an incomplete cardiac response to thyroid hormone is present in RTH.