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.     

Serial cardiorespiratory exercise testing in patients with congenital heart disease

Aerobic capacity of patients with different forms of congenital heart disease was serially evaluated in 79 patients and the evolution was correlated with the lesion and the level of daily activity. The patients were divided into six groups: patients with a small ventricular septal defect (VSD) with mini shunt (n=14), mild pulmonary valve stenosis with gradient <40 mm Hg (PS) (n=12), mild to moderate aortic valve stenosis (gradient 36±17 mm Hg) (AS) (n=12), patients 4.7±2.1 years after repair of tetralogy of Fallot (PO-TF) (n=16), patients 2.2±2.9 years after closure of a high flow/high gradient VSD (PO-VSD) (n=13), and patients 2.6±1.7 years after Fontan repair (Fontan-PO) (n=12). Aerobic capacity was assessed by determination of the ventilatory anaerobic threshold (VAT). VAT reflects the highest aerobic exercise level prior to a disproportionate increase of CO₂ and ventilation relative to O₂ uptake; it is independent of patient motivation. Data are expressed as percentage of normal O₂ uptake at VAT, determined in 234 age/gender matched controls. The habitual level of physical activity was assessed by a standardised questionnaire. Aerobic capacity in all subgroups of patients, even with very mild defects, was at or below the lower limit of normal. Children left unrestricted from physical exercise (VSD, PS, PO-VSD) had no change over the study period. However, aerobic capacity of patients with medically imposed physical restrictions (AS) and significant residual haemodynamic lesions (PO-TF, Fontan) decreased with age. In patients with AS, PO-TF and Fontan-PO the habitual level of physical activity was significantly decreased compared to controls.Conclusion Cardiovascular exercise performance in children with medically imposed restriction of intensive physical exercise (AS) or residual haemodynamic lesions (TF and Fontan-PO) declines progressively during medium-term follow up. In the other patient groups (VSD, PS, VSD-PO), exercise performance remains stable.Deceased     

Ambulatory blood pressure in patients with occult recurrent coarctation of the aorta

The hypothesis that mild recurrent aortic obstruction produces subtle changes in ambulatory blood pressure was investigated by performing 24-hour monitoring on 11 postoperative coarctation patients. Patients (age 16.1±2.7 years) were compared with normal controls (age 15.7±2.5 years,n=15). Surgery (end-to-end anastomosis) was performed at 6.0±1.0 years of age. There were no significant differences between patients and controls in terms of baseline blood pressure (right arm 123/78±4/3 mmHg versus 120/75±3/2 mmHg) or right leg systolic pressure (125±6 mmHg versus 123±4 mmHg). Of the 11 patients 8 had recoarctation by Doppler study (mean gradient 25.3±2.1 mmHg), 5 of 11 had a postexercise arm-leg pressure difference of>30 mmHg, and 6 patients had aortic diameters at the site of surgery <70% of the descending aortic diameter (by magnetic resonance imaging). There were no significant differences between the coarctation and control groups in terms of mean ambulatory systolic (125±3 mmHg versus 119±2 mmHg) or diastolic (69±2 mmHg versus 72±2 mmHg) pressures throughout the day. However, coarctation patients had a larger number of systolic pressures that exceeded the 95th percentile (18.2±5.6% versus 6.8±1.2%). These labile increases in systolic pressure correlated with residual coarctation (r=0.642,p=0.003). Ambulatory monitoring is a useful tool for detecting and monitoring subtle abnormalities of blood pressure control after coarctation repair.     

Physical fitness of urban American children

The Bruce treadmill protocol was used to evaluate the exercise endurance in a pediatric urban population. The sample population consisted of 525 healthy children 4 to 18 years of age (303 males and 222 females). Endurance time increased with age in males and increased up to 10 to 12 years of age in females, thereafter leveling off. Results were compared with those of a widely used standard reference of normal for treadmill exercise testing in children. Mean endurance times were significantly shorter compared to those of the reference study (p < 0.03). When the subjects were grouped in percentiles based on the reference study, 61% of males and 81% of females performed below the 25th percentile. There was a strong negative correlation between body mass index and endurance time (p < 0.0001), suggesting that obesity is a major contributor to decreased physical fitness. Compared to subjects in the reference study, children from a large U.S. metropolitan area have markedly diminished exercise endurance times, suggesting poor physical fitness. Inactivity with consequent lack of fitness, if unchecked, are likely to lead to cardiovascular disorders in adulthood. Efforts should be made to encourage physical fitness in children.     

Exercise Stress Echocardiography After Childhood Ross Surgery: Functional Outcome in 26 Patients From a Single Institution

Adult studies suggest a better functional outcome after aortic valve replacement with a pulmonary autograft compared with mechanical or homograft valves. Little is known about functional results after Ross surgery in growing children. This study reports formal exercise stress echocardiographic data from 26 pediatric Ross patients. A retrospective cohort study analyzed stress echocardiographic data of patients who underwent Ross surgery as a child (<17 years old). All patients were operated by a single surgeon and underwent a Bruce protocol stress echocardiogram on the treadmill. Twenty-six patients (4 girls) were 9.3 ± 5.0 years at surgery and 14.9 ± 3.5 years (range 6.6-19.7 years) at follow-up. Mean follow-up was 5.4 ± 3.7 years (median 4.2). All were asymptomatic. The exercise time was normal in 87% of cases at 12.8 ± 2.5 min. On stress echocardiography, the mean right-ventricular outflow tract (RVOT) gradient increased from 38 ± 22 mmHg at rest to 82 ± 33 mmHg after exercise, but this did not correlate with exercise times. Stress echocardiography is useful in evaluating patients after childhood Ross surgery for aortic valve disease. In this pediatric cohort, most patients achieved normal exercise capacity. The presence of mild or moderate RVOT obstruction had no significant impact on exercise capacity.     

Exercise Testing is Useful to Screen for Residual Coarctation in Children

Twenty-seven children (ages 8 to 18 years) who had a history of successful coarctation repair (mean transisthmic Doppler gradient [TI-D] <20 mmHg at rest) and had not received antihypertensive medications underwent echocardiogram at rest and immediately following peak exercise with a standard treadmill test. All were normotensive or had isolated systolic hypertension at rest. Right arm-ankle (RA-A) systolic blood pressure (SBP) difference and TI-D were measured. Eleven children (41%) demonstrated exercise-induced hypertension (peak exercise SBP >98th percentile per body surface area) and 17 (63%) had a mean TI-D ≥40 mmHg. Eight underwent MRI or angiography; a residual coarctation (RCoA) was confirmed in three and excluded in five. RCoA was excluded in three other children who were normotensive at rest and had normal postoperative echocardiographic findings. No individual test (SBP, RA-A SBP, TI-D) at rest or with exercise testing was statistically useful to identify RCoA. However, the requirement for a RA-A SBP difference ≥20 mmHg and a TI-D ≥40 mmHg during exercise testing was a useful screen: RCoA was present in three of five children who fit these criteria but was absent in six of six who did not.     

Impaired Poststenotic Aortic Pulsatility After Hemodynamically Ideal Coarctation Repair in Children

Using echocardiographic quantification of aortic pulsatility distal to the site of the surgical anastomosis, we evaluated whether the preoperatively impaired poststenotic aortic pulsatility returned to normal after repair of coarctation with a hemodynamically ideal result. Patients who underwent repair of aortic coarctation without residual obstruction were compared to a matched group of normal children. A standardized M-mode echocardiographic evaluation of the aorta at the diaphragmatic level was performed for all patients. Measurements consisted of maximum and minimum aortic diameters, time intervals, and a calculated pulsatility index. Compared to normal children (n = 19), 20 children with operated coarctation and with a hemodynamically ideal result showed a significantly smaller increase in aortic diameter in systole (mean of 29 ± 7% in patients versus 37 ± 7% in normals; p < 0.01). In contrast to patients with coarctation in whom the maximum aortic distension is reached much later during the cardiac cycle, hemodynamically normalized, operated patients in our study had no such delay (maximum aortic pulsation at 28% of cardiac cycle time compared to 27% in normals; p = not significant). The pulsatility index of the poststenotic aorta was clearly lower in operated children (mean, 130 ± 50%/sec) compared to a normal mean value of 202 ± 33%/sec but was still significantly higher than that in patients with unoperated coarctation, who showed a low mean value of 51 ± 24%/sec (p < 0.01). After correction of aortic coarctation with a hemodynamically ideal result, the pulsatility of the poststenotic aorta, severely impaired prior to repair, did not return to normal during the observation period in the patients studied.     

Brock transventricular pulmonary valvotomy in patients with pulmonary stenosis: Long-term results

Summary As no long-term results of a blind opening up of the pulmonary valve either by balloon valvoplasty or closed Brock valvotomy have been published, we examined the outcome of 12 patients with valvar pulmonary stenosis 17±5 (11–22) years after surgery. The Brock valvotomy had been carried out at a mean age of 3±2.8 (0.2–8.5) years. The mean pressure gradient across the right ventricular outflow tract had been 116±45 (75–97) mmHg at the catheter study or 106±43 (40–160) mmHg as measured intraoperatively. The right ventricular pressure after the Brock procedure was measured in the operating room in five patients as 46±15 (30–60) mmHg. Seven patients had been recatheterized at a mean age of 9.5±2 (7–12.7) years; at that time the gradient across the pulmonary valve had been 20±14 (10–37) mmHg. At a mean age of 21.7±3 (15–26) years these and five further patients were reexamined by echo Doppler. This time the pressure gradient across the pulmonary valve was 13±6 (7–20) mmHg. Moderate pulmonary incompetence was present in four and mild incompetence in eight patients; two had mild tricuspid insufficiency. All except one patient, who had suffered a cerebrovascular accident before surgery, were in NYHA functional class 1 and pursuing a profession. From these data we conclude that the blind opening-up of the pulmonary valve achieves excellent long-term palliation.     

Responses of non-obese white children to treadmill exercise

OBJECTIVE: To determine the response to maximal treadmill exercise with the Bruce protocol in a cohort of healthy non-obese American children and adolescents. STUDY DESIGN: A retrospective review of treadmill exercise studies on 347 white American children (188 boys, 159 girls) aged 5 to 18 years was performed with metabolic criteria to verify maximal exercise effort. Data on exercise endurance time, heart rate, blood pressure, and metabolic variables were assessed and compared between age groups and sexes by unpaired t testing and analysis of variance. RESULTS: Exercise endurance time was lower in all age groups when compared with earlier published data. Girls had a lower endurance time than boys at all ages. There was no significant difference in maximum heart rate with respect to age or sex. The maximum systolic blood pressure and diastolic blood pressure increased with increasing age in both boys and girls. Boys had significantly higher maximum systolic blood pressure and diastolic blood pressure after 13 years of age. The maximum absolute oxygen consumption and indexed oxygen consumption showed similar trends for both sexes. CONCLUSION: Lower exercise endurance times are seen despite physiologic evidence of maximal effort, raising the possibility that cardiovascular conditioning is reduced in contemporary American children.     

Exercise Tolerance and Blood Pressure Response to Exercise Testing in Children and Adolescents After Renal Transplantation

The aim of the study was to assess exercise tolerance and blood pressure (BP) response to treadmill exercise in children after renal transplantation. Forty-five children were selected (29 males and 16 females) whose mean age was 14.3 ± 4.2 years. All children had Hb ≥ 10 g/dl and creatinine clearance ≥40 ml/min/1.73 m². They were at least 6 months posttransplantation and were on triple immunosuppressive therapy. Twenty-seven were also on various antihypertensive medications. Each underwent clinical examination and measurement of BP, both at rest and during exercise testing on treadmill. The test was stopped on muscular fatigue or exhaustion. The patients were divided into two groups: those off (A) or on (B) antihypertensive therapy. When compared to a population of healthy children the patients had reduced exercise tolerance (10.1 ± 2.1 vs 15.1 ± 1.7 min, p < 0.001) (67 ± 16%), increased heart rate (174 ± 19 vs 161 ± 19 beats/min, p < 0.001) (109 ± 15%), and increased maximum systolic BP (150 ± 26 vs 134 ± 13 mmHg, p < 0.001) (113 ± 19%) at comparable workloads. Within the two patient groups, significant differences were observed during exercise testing for maximum heart rate, which was lower in group B (p= 0.03), and maximum systolic BP, which was higher in group A (p= 0.04). Our study confirms that children and adolescents on immunosuppressive therapy after renal transplantation have a hypertensive response during exercise, probably related to medication-induced peripheral vascular tone.     

Altered cardiac repolarization during exercise in congenital aortic stenosis

Summary The incidence of sudden death in children with congenital aortic stenosis (CAS) varies between 4 and 20%. In several syndromes sudden death is associated with a long QT interval in the electrocardiogram (ECG). The aim of the study was to evaluate the cardiac repolarization in CAS during stress.We included 40 children and young persons, 20 with CAS and 20 healthy controls. All underwent echocardiographic study and treadmill stress test. The QT and relative RR intervals were measured in leads II and V6 at rest and during exercise at preselected heart rates. Mean values of QT were compared by analysis of variance, Student'st-test, and linear regression method.No statistically significant differences in the resting ECG were found between the two groups, whereas during exercise the mean QT of the CAS group was significantly longer than in the controls (p<0.05), except at a heart rate of 140±5. Our study demonstrates that patients with CAS have transiently altered cardiac repolarization when there are sudden variations in heart rate.Such a defect could predispose patients with CAS to fatal arrhythmias and sudden death.     

Circulating somatomedin-C levels and the effect of growth hormone-releasing factor on plasma levels of growth hormone and somatostatin-like immunoreactivity in obese children

The effect of growth hormone-releasing factor (GRF) 1-44 on growth hormone and somatostatin release in plasma has been studied in 20 obese children. Twenty age and sex-matched children with normal weight served as controls. Mean peak growth hormone response in obese children after 1 g/kg body wt. GRF 1-44 was significantly lower than in controls (23.7±3.6 ng/ml vs. 41.1±3.0 ng/ml;P<0.01), as were mean integrated growth hormone response areas (1544±272 ng×ml^-1×2 h vs. 2476±283 ng×ml^-1×2 h;P<0.01). Mean plasma levels of somatostatin-like immunoreactivity did not change after GRF in both goups. Mean somatomedin-C levels in obese children were significantly higher compared to controls (1.6±0.4 U/ml vs. 0.86±0.4 U/ml;P<0.01). Somatomedin-C levels were not related to the integrated growth hormone responses. In conclusion there is no relation between somatomedin-C levels and the reduced growth hormone-releasing effect of GRF in obese children. GRF does not alter peripheral somatostatin-like immunoreactivity levels either in normal or obese children.Abbreviations Sm-C somatomedin C - GRF growth hormone-releasing factor - GH growth hormone - SLI somatostatin-like immunoreactivity     

Autologous Ross Operation for Congenital Aortic Stenosis

Congenital aortic stenosis is a relatively common cardiac anomaly encountered in approximately 5% of all children with heart disease. The Ross procedure is increasingly used for replacement of the aortic valve in children. We report a 12-year-old boy who was born with congenital aortic stenosis secondary to a bicommissural aortic valve. The patient underwent open valvotomy in infancy and aortic valvuloplasty 2 years later. Residual/recurrent stenosis prompted referral for aortic valve replacement, and he underwent an autologous Ross procedure, in which the aortic root was replaced with a pulmonary autograft and the repaired aortic valve was used to restore right ventricular-to-pulmonary artery continuity. The postoperative course was unremarkable. Nitroprusside, esmolol, and labetolol were used to control postoperative hypertension. He was discharged 4 days after surgery on oral furosemide and aspirin, and he has had no cardiovascular symptoms during follow-up. Recent echocardiography demonstrated mild right ventricular outflow tract obstruction with a peak velocity of 3.6 m/sec, with a gradient of 42 mmHg and moderate pulmonary insufficiency. There was no left ventricular outlet tract obstruction or aortic insufficiency.     

Aortic Stenosis: The Spectrum of Practice

There is significant variation in practice patterns in managing congenital aortic valve stenosis. Review of medical literature reveals no significant information regarding the current practice methods in the treatment of a simple lesion such as aortic stenosis (AS). Therefore, this survey-based study was conducted in an attempt to better understand the uniformity or heterogeneity of practice in treating AS. A questionnaire was prepared to evaluate the style of management of AS. This survey was designed to assess the practice of follow-up visitations, type and frequency of investigative studies, pharmacological therapy, and exercise recommendations. Questions about therapeutic intervention included those of timing and type of intervention. Questionnaires were sent to all academic pediatric cardiology programs in the United States (48 program) and selected international programs from Europe, Asia, and Australasia (19 program). The total number of surveys sent out was 67, and the total number of respondents was 25 (37%), 15 (31%) from the United States and 9 (53%) from outside the United States. The definition of moderate AS varied among respondents. The range provided for mild AS was identified as that with a peak-to-peak pressure gradient of < 25–30 mmHg, peak instantaneous Doppler gradient of < 36–50 mmHg, or mean Doppler gradient of < 25–40 mmHg. On the other hand, severe AS was defined as that with a peak-to-peak gradient of > 50–60 mmHg, peak instantaneous Doppler gradient of > 64–80 mmHg, or mean Doppler gradient of > 45–64 mmHg. In assessing follow-up patterns, 84% of respondents recommended seeing patients with mild AS annually, the longest time of follow-up listed in the questionnaire, whereas 20% suggested follow-up every 6 months. There was no consensus among survey centers regarding follow-up of patients with moderate AS. For severe AS, 16% recommend immediate intervention, 16% arrange follow-up every 6 months, and 56 and 28% recommend follow-up in 3 and 1 month(s), respectively. In making the decision to proceed with biventricular versus univentricular repair in patients with AS in the neonatal period, many factors were considered. Ninety-two percent of respondents rely on mitral valve z score, 84% on aortic valve z score, 52% on left ventricle length, 48% on the presence of antegrade ascending aorta flow, and only 32% considered significant endocardial fibroelastosis as a factor. Rhodes score was used by 20% of respondents in decision making regarding the approach to management of this subset of AS. This study shows that there is consensus in the management of mild and severe forms of AS. As expected, disagreement is present in the definition, evaluation, and therapy of moderate aortic valve stenosis. There is a tendency for catheter intervention except in the presence of dysplastic aortic valve or moderate to severe aortic regurgitation. There is also disagreement regarding methods used to determine biventricular versus univentricular repair of a borderline hypoplastic left heart.     

Exercise Testing and 24-Hour Ambulatory Blood Pressure Monitoring in Children with Williams Syndrome

The aim of the study was to assess workload capacity and blood pressure (BP) response to treadmill exercise and 24-hour BP monitoring in children with Williams syndrome. Seventeen children were examined (8 males and 9 females) whose mean age was 13.8 ± 3.6 years. Six patients were on antihypertensive therapy. Each patient underwent clinical examination and measurement of BP at rest, during exercise, and during 24-hour monitoring. Two-dimensional echocardiogram and echo-Doppler of renal arteries were performed. The test was stopped for muscular fatique or reduced cooperation. The patients, when compared to a population of healthy children, had reduced total time of exercise (7.3 ± 1.9 vs 14.3 ± 2.6 min, p < 0.001) and, at the same workload, increased heart rate (167 ± 19 vs 145 ± 16 beats/min, p < 0.001) and increased maximum systolic BP (146 ± 27 vs 128 ± 12 mmHg, p = 0.01). Ambulatory blood pressure measurement values showed higher systolic blood pressure both during daytime and nighttime. Our study confirms that children and adolescents with Williams syndrome are at high risk for hypertension, probably related to the alterations of large arteries. The data relating to the synthesis of elastin may have a direct relationship to the compliance of the arterial system, leading to hypertension.     

Moderate sedation for MRI in young children with autism

Autism is a pervasive neurodevelopmental disorder. Because of the deficits associated with the condition, sedation of children with autism has been considered more challenging than sedation of other children. Objective: To test this hypothesis, we compared children with autism against clinical controls to determine differences in requirements for moderate sedation for MRI. Materials and methods: Children ages 18–36 months with autism (group 1, n = 41) and children with no autistic behavior (group 2, n = 42) were sedated with a combination of pentobarbital and fentanyl per sedation service protocol. The sedation nurse was consistent for all patients, and all were sedated to achieve a Modified Ramsay Score of 4. Demographics and doses of sedatives were recorded and compared. Results: There were no sedation failures in either group. Children in group 1 (autism) were significantly older than group 2 (32.02±3.6 months vs 28.16±6.7 months) and weighed significantly more (14.87±2.1 kg vs 13.42±2.2 kg). When compared on a per-kilogram basis, however, group 1 had a significantly lower fentanyl requirement than group 2 (1.25±0.55 mcg/kg vs 1.57±0.81 mcg/kg), but no significant difference was found in pentobarbital dosing between groups 1 and 2, respectively (4.92±0.92 mg/kg vs 5.21±1.6 mg/kg). Conclusion: Autistic children in this age range are not more difficult to sedate and do not require higher doses of sedative agents for noninvasive imaging studies.     

Surgical outcome of congenital valvar aortic stenosis

Valvar aortic stenosis is a common congenital heart defect for which surgical procedures can be done with low risk except in infants whose conditions are seriously compromised. The purpose of this report was to present our experience with the results of surgical aortic valvotomy for congenital valvar aortic stenosis performed at our hospital. The study group consisted of 24 patients, 3 females and 21 males, with ages ranging from 1 to 15.5 years (mean age 8.5 years), who underwent aortic valvotomy for valvar aortic stenosis. The case records of all the patients were retrospectively reviewed. They were followed for 1-10.5 years (mean 5.02+/-2.38 years) after relief of aortic stenosis, and were scheduled for reevaluation. Sixteen of the 24 patients were recatheterized and 15 (93.7%) were found to have aortic regurgitation on angiography. Peak systolic pressure gradients (mean+/-SD) were 65.9+/-19.5 mmHg before and 36.7+/-14.8 mmHg (p<0.05) after the operatilon. Of the 24 patients, 45.8% had a new postoperative diastolic murmur. Twenty patients (83.3%) had residual stenosis and three (12.5%) had recurrent stenosis. Two patients (8.3%) had undergone reoperation six to seven years after the initial aortic valvotomy, and most of the others will require reoperation in the future. No sudden deaths occurred in this series. Timely relief of obstruction prevents sudden death and produces symptomatic improvement in valvar aortic stenosis, but aortic valvotomy is only a palliative measure.     

Cardiovascular Hemodynamics: Relationships with Insulin Resistance in Obese Children

We investigated blood pressure (BP), cardiac output (CO), and systemic vascular resistance (SVR) and their relationships with insulin and glucose blood levels in a group of 24 obese children (mean age, 11.9 ± 2.1 years; 19 males). The data were compared to those obtained from a group of 19 healthy controls of the same age (12.4 ± 2.1 years; p = NS; 13 males). BP at rest was measured and all subjects underwent an exercise testing on the treadmill (Bruce Prot.), time of exercise, maximal heart rate, maximum systolic blood pressure, CO, and SVR at rest and at peak exercise were considered. Only in the OC group were an oral glucose tolerance test were performed to calculate insulin sensitivity index (ISI) and echocardiography performed to determine the left ventricular mass (LVM). The relationships between cardiovascular and metabolic parameters were investigated. Students t-test and linear regression analysis were used when appropriate. OC had a significant reduction in TE and higher BP, and linear regression analysis showed significant correlations between BP, ISI, and LVM. We speculate that OC need a regular cardiovascular and metabolic screening to prevent the development of early cardiovascular damage.     

Echocardiographic evaluation of the aortic root and mitral valve in children and adolescents with isolated pectus excavatum: Comparison with Marfan patients

Summary Pectus excavatum, mitral valve prolapse (MVP), and dilated aortic root occur frequently in patients with Marfan's syndrome (MS). Patients with isolated pectus excavatum (IPE) have a high prevalence of MVP, but it is not known whether aortic root dilatation is a risk in those patients. To test the hypothesis that IPE and MS represent a spectrum of connective tissue dystrophy with MV and aortic root involvement, two-dimensional (2D) echocardiography was used to measure the aortic root diameter and assess for MVP in IPE (n=31), MS (n=14), and normal (n=16) gender- and age-matched patients. Aortic root was measured in parasternal long- and short-axis views, just above the aortic sinuses, at end systole, in six cardiac cycles, and averaged. Parasternal long-axis view was used to assess for MVP.Aortic root diameter in IPE patients was not different from that in normal subjects, 24±4 mm vs 22±4 mm (p=NS), respectively, both were significantly smaller than that in MS patients (30±5 mm;p<0.05).MVP was present in 17 of 31 (55%) IPE patients vs 12 of 14 (86%) MS patients (p=NS) and in only 1 of 16 (6%) normal subjects (p<0.05) vs both IPE and MS. We conclude that young patients with IPE represent an isolated form of connective tissue abnormality because of the presence of pectus excavatum and MVP, but this is different from the systemic involvement of MS because of the lack of other systemic findings, including aortic root dilatation and changes in body habitus.     

Cardiorespiratory Exercise Tolerance in Asymptomatic Children with Ebstein's Anomaly

The aim of the study was to evaluate cardiorespiratory exercise tolerance in asymptomatic children with Ebstein's anomaly. Eleven children with a mean age of 9.6 years were prospectively studied by spirometry, cardiopulmonary exercise testing (bicycle ergometer n= 8, treadmill test n= 3), and contrast echocardiography. A right-to-left atrial shunt was detected by contrast echocardiography in 7 children (group 1), whereas no shunt was found in 4 (group 2). VO₂ max was decreased [84.5 (SD = 16.8)] and was strongly correlated to oxygen saturation in group 1 (p < 0.0001). Oxygen saturation at peak uptake was significantly decreased compared to baseline [97.4 (SD = 2.0) vs 90% (SD = 9.5%), p= 0.02] and was significantly lower in group 1 than in group 2 [85.7 (2.2) vs 98.2% (SD = 1.2%), p= 0.03]. Oxygen desaturation was related to a right-to-left atrial shunt (p= 0.01). Decreased VO₂ max was also correlated to the small size of the left ventricle (p= 0.05). We concluded that decreased exercise tolerance in children with asymptomatic Ebstein's anomaly is related to a right-to-left atrial shunt and to a small left ventricle. In case of poor exercise tolerance, a contrast echocardiography should be performed to detect an atrial septal defect.