Greater Arterial Stiffness in Children with or without Second-generation Antipsychotic Treatment for Mental Health Disorders: Rigidité Artérielle Plus Importante Chez Les Enfants Avec ou Sans Traitement Par Antipsychotiques de la Deuxième Génération Pour des Troubles de Santé Mentale

OBJECTIVE

Second-generation antipsychotics (SGAs) are used for a variety of mental disorders and are associated with cardiometabolic side effects in children. The objective of this study was to assess the cardiovascular health of children with mental disorders that are SGA-treated or SGA-naive.

METHODS

SGA-treated (n = 47) or SGA-naive (n = 37) children (aged 6 to 18 years) with mental disorders and control children (n = 83, no mental disorder) underwent assessment for cardiac function and morphology by echocardiography, aortic pulse wave velocity (PWV), and carotid intima-media thickness (cIMT). Body mass index (BMI) z-scores, waist circumference z-scores, systolic and diastolic blood pressure (BP) percentiles for height and sex, and fasting plasma glucose, insulin, triglycerides, and cholesterol were also assessed. Differences between SGA-treated, SGA-naive, and control children were assessed by linear and log-linear regression models.

RESULTS

SGA-treated children had greater BMI z-scores and overweight/obesity (BMI ≥ 85th percentile for age and sex) and hypertension than SGA-naive and control children. The PWV geometric mean was 11.1% higher in SGA-treated (95%CI, 3.95 to 18.77) and 12.9% higher in SGA-naive children (95% CI, 5.60 to 20.59) compared to controls in models adjusted for age, sex, BMI, and systolic BP percentile. Left ventricular (LV) end-diastolic dimension/body surface area (BSA), LV end-systolic dimension/BSA, and LV ejection fraction were lower in SGA-treated and SGA-naive children compared to controls in models adjusted for sex and age.

CONCLUSIONS

Children with mental disorders have greater arterial stiffness and altered cardiac structure/function than children with no mental health diagnosis. SGA treatment in children is not associated with alterations in cardiovascular structure/function.

Aortic Dimensions, Biophysical Properties, and Plasma Biomarkers in Children and Adults with Marfan or Loeys-Dietz Syndrome

Background

Aortic dilation, stiffening, and dissection are common and potentially lethal complications of Marfan syndrome (MFS) and Loeys-Dietz syndrome (LDS), which involve abnormal transforming growth factor beta (TGF-β) signalling. The relation of aortic dimensions, stiffness, and biomarker levels is unknown. The objective of this study was to measure aortic dimensions, stiffness, TGF-β and matrix metalloproteinase (MMP) levels, and endothelial function in patients with MFS, and to compare TGF-β levels in patients with MFS receiving different therapeutic regimens.

Methods

This was a cohort study of 40 MFS and 4 LDS patients and 87 control participants. Aortic dimension and stiffness indexes, including pulse wave velocity (PWV), were measured using echocardiography and Doppler. Total and free TGF-β and MMP blood levels were measured using Quantikine (R&D Systems, Inc, Minneapolis, MN) and Quanterix (Billerica, MA) kits. Endothelial function was measured using brachial artery flow-mediated dilation.

Results

PWV was increased in patients with MFS. There were increased MMP-2 levels in those with MFS but no increase in free or total TGF-β or MMP-9 levels compared with control participants. There was no difference in TGF-β levels between MFS patients receiving no medications, angiotensin receptor blockers, and β-blockers. PWV correlated most strongly with age. Endothelial function showed premature gradual decline in patients with MFS.

Conclusions

Despite the increased PWV, monitoring aortic stiffness or TGF-β levels would not be helpful in patients with MFS. TGF-β levels were not increased and the increased MMP-2 levels suggest consideration of a different therapeutic target.

Physiological Responses to Exercise in Pediatric Heart Transplant Recipients

INTRODUCTION

Pediatric heart transplant (HTx) recipients have reduced exercise capacity typically two-thirds of predicted values, the mechanisms of which are not fully understood. We sought to assess the cardiorespiratory responses to progressive exercise in HTx relative to controls matched for age, sex, body size, and work rate.

METHODS

Fourteen HTx recipients and matched controls underwent exercise stress echocardiography on a semisupine cycle ergometer. Hemodynamics, left ventricular (LV) dimensions, and volumes were obtained and indexed to body surface area. Oxygen consumption (V˙O2) was measured, and arteriovenous oxygen difference was estimated using the Fick Principle.

RESULTS

At rest, LV mass index (P = 0.03) and volumes (P < 0.001) were significantly smaller in HTx, whereas wall thickness (P < 0.01) and LV mass-to-volume ratio (P = 0.01) were greater. Differences in LV dimensions and stroke volume persisted throughout exercise, but the pattern of response was similar between groups as HR increased. As exercise progressed, heart rate and cardiac index increased to a lesser extent in HTx. Despite this, V˙O2 was similar (P = 0.82) at equivalent work rates as HTx had a greater change in arteriovenous oxygen difference (P < 0.01).

CONCLUSIONS

When matched for work rate, HTx had similar metabolic responses to controls despite having smaller LV chambers and an attenuated increase in hemodynamic responses. These findings suggest that HTx may increase peripheral O2 extraction as a compensatory mechanism in response to reduced cardiovascular function.

Non-invasive assessment of aortic stiffness and blood pressure in young Turner syndrome patients

Background Females with Turner syndrome (TS) carry an elevated risk of aortic dissection. The objective of the study was to assess the biophysical properties of the aorta and ambulatory blood pressure (BP) in females with TS and compare these findings to those in healthy female age-matched controls. Methods This was a prospective cohort study including subjects aged 8-25 years. Utilizing two-dimensional (2D) echocardiography and Doppler, proximal aortic dimensions were measured and biophysical properties of the aorta were calculated including pulse wave velocity (PWV), arterial pressure-strain elastic modulus and stiffness index. Resting BP was measured and ambulatory blood pressure monitoring (ABPM) was performed. Results Of 23 TS patients and 46 controls (median age 16.3 years), aortic annulus, sinus of Valsalva and sinotubular (ST) junction diameters, as well as left ventricular (LV) mass, were significantly greater in TS patients compared with controls when scaled for height2.7, but not for body surface area (BSA), although ascending aorta diameter was greater when scaled for both. Median PWV was faster in TS patients compared to controls (451 vs. 360 cm/s) while arterial pressure-strain elastic modulus and stiffness index were similar. Resting BP was abnormal in seven out of 22 patients and ABPM was abnormal in 16 out of 21 patients. Conclusions Young patients with TS had dilated proximal aortas when scaled for height2.7 and stiffer aortas when compared with healthy female age-matched controls. Moreover, resting BP underdiagnosed pre-hypertension and hypertension compared to ABPM. These findings are consistent with the presence of a primary aortopathy in TS.

In vivo characterization of doxycycline-mediated protection of aortic function and structure in a mouse model of Marfan syndrome-associated aortic aneurysm

Aortic aneurysm is the most life-threatening complication in Marfan syndrome (MFS) patients. Doxycycline, a nonselective matrix metalloproteinases inhibitor, was reported to improve the contractile function and elastic fiber structure and organization in a Marfan mouse aorta using ex vivo small chamber myography. In this study, we assessed the hypothesis that a long-term treatment with doxycycline would reduce aortic root growth, improve aortic wall elasticity as measured by pulse wave velocity, and improve the ultrastructure of elastic fiber in the mouse model of MFS. In our study, longitudinal measurements of aortic root diameters using high-resolution ultrasound imaging display significantly decreased aortic root diameters and lower pulse wave velocity in doxycycline-treated Marfan mice starting at 6 months as compared to their non-treated MFS counterparts. In addition, at the ultrastructural level, our data show that long-term doxycycline treatment corrects the irregularities of elastic fibers within the aortic wall of Marfan mice to the levels similar to those observed in control subjects. Our findings underscore the key role of matrix metalloproteinases during the progression of aortic aneurysm, and provide new insights into the potential therapeutic value of doxycycline in blocking MFS-associated aortic aneurysm.

Echocardiographic Assessment of Ventricular Function During Exercise in Adolescent Female Patients With Anorexia Nervosa

BACKGROUND

Patients with anorexia nervosa (AN) have altered physiologic responses to exercise. The aim of this study was to investigate exercise capacity and ventricular function during exercise in adolescent patients with AN.

METHODS

Sixty-six adolescent female patients with AN and 21 adolescent female control subjects who exercised to volitional fatigue on a semisupine ergometer, using an incremental step protocol of 20 W every 3 min, were retrospectively studied. Heart rate, blood pressure, and echocardiographic Doppler indices were measured at rest and during each stage of exercise. Fractional shortening, rate-corrected mean velocity of circumferential fiber shortening, stress at peak systole, cardiac output, and cardiac index were calculated. Minute ventilation, oxygen consumption, carbon dioxide production, and respiratory exchange ratio were measured using open-circuit spirometry.

RESULTS

Patients with AN had significantly lower body mass index (16.7 vs 19.7 kg/m², P < .001), total work (1,126 vs 1,914 J/kg, P < .001), and test duration (13.8 vs 20.8 min, P < .001) compared with control subjects. Peak minute ventilation, oxygen consumption, and carbon dioxide production were significantly decreased in patients with AN. Heart rate, systolic blood pressure, cardiac index, fractional shortening, and rate-corrected mean velocity of circumferential fiber shortening demonstrated similar patterns of increase with progressive exercise between groups but were decreased at peak exercise in patients with AN. Body mass index percentile, age, peak oxygen consumption, and peak cardiac output were independently associated with exercise duration.

CONCLUSIONS

Adolescent patients with AN have reduced exercise capacity and peak cardiovascular indices compared with control subjects but normal patterns of cardiovascular response during progressive exercise. Systolic ventricular function is maintained during exercise in adolescents with AN.

Doppler Echocardiography Assessment of Aortic Stiffness in Female Adolescents with Anorexia Nervosa

BACKGROUND

Anorexia nervosa (AN) is associated with abnormalities in biomarkers of cardiovascular risk. Arterial stiffness, as measured by pulse-wave velocity (PWV), is also a risk factor for cardiovascular disease. The aims of this study were to determine the stiffness of the aorta in female adolescents with AN and to determine if either the severity or the type of AN was associated with PWV.

METHODS

This was a retrospective case-control study. Adolescent patients with a clinical diagnosis of AN were included. Aortic diameter and pulse-wave transit time over a portion of the thoracic aorta were measured using Doppler echocardiography, and PWV was calculated.

RESULTS

There were 94 female patients with AN and 60 adolescent female control subjects. There was no significant difference in age between patients with AN and control subjects (15.5 ± 1.7 vs 15.1 ± 2.6 years, P = .220). Body mass index (16.0 ± 2.4 vs 19.7 ± 2.7 kg/m², P < .001) and body mass index percentile (9.4 ± 15.6 vs 45.5 ± 26.2, P < .001) were significantly lower for patients with AN than control subjects. PWV (443 ± 106 vs 383 ± 77 cm/sec, P < .001) was significantly higher in patients with AN than control subjects. Similar differences from control subjects were found in patients with AN with both lower and higher body mass index percentiles and also in patients with AN with the restrictive or the binge-purge subtype.

CONCLUSIONS

Female adolescents with AN have increased aortic stiffness compared with control subjects. This study suggests that patients with AN may be at increased risk for future cardiovascular disease. Future studies are required to determine the reversibility of these changes with weight restoration.

A Doppler Echocardiographic Study of the Myocardial Inotropic Response to Peak Semisupine Exercise in Healthy Children: Development of a Simplified Index of Myocardial Reserve

BACKGROUND

Stress echocardiography has been advocated for the detection of abnormal myocardial function and unmasking diminished myocardial reserve in pediatric patients. The aim of this study was to create a simplified index of myocardial reserve, derived from the myocardial inotropic response to peak semisupine exercise in healthy children, and illustrate its applicability in a sample of pediatric oncology patients.

METHODS

In this prospective analysis, children (7-18 years of age) with normal cardiac structure and function performed semisupine stress echocardiography to volitional fatigue. The quotient of wall stress at peak systole and heart rate-corrected velocity of circumferential fiber shortening were calculated at baseline and at peak exercise, the difference of which was termed the index of myocardial reserve (IMR). The IMR was also calculated in a retrospective sample of pediatric oncology patients with normal resting left ventricular function who had received anthracycline treatment and had performed the same exercise protocol to illustrate utility.

RESULTS

Fifty healthy subjects (mean age, 13.2 ± 2.6 years) and 33 oncology patients (mean age, 12.7 ± 4.0 years) were assessed. In the healthy children at peak exercise, heart rate-corrected velocity of circumferential fiber shortening significantly increased (from 1.17 ± 0.17 to 1.58 ± 0.24 circ · sec^-1, P < .001), while the quotient of wall stress at peak systole significantly decreased (from 75.3 ± 17.1 to 55.3 ± 13.8 g · cm^-2, P < .001), shifting the plot of the relationship between the two parameters upward and to the left. The mean IMR was -30.8 ± 17.8, and the normal distribution ranged from -4.7 (fifth percentile) to -67.3 (95th percentile). The IMR was abnormal in 10 oncology patients who were treated with anthracyclines.

CONCLUSIONS

The authors have developed a novel IMR. Relative to the normal distribution of this IMR in healthy subjects, it is possible to identify patients with abnormal myocardial reserve. Thus, this study demonstrates the application of the IMR to aid in clinical decision making in individual patients.

Stress Echocardiographic Evaluation for D-Transposition of the Great Arteries after Atrial Redirection: Unmasking Early Signs of Myocardial Dysfunction and Baffle Stenosis

BACKGROUND

The authors used semisupine cycle ergometry stress echocardiography to assess cardiac function and unmask baffle stenosis in patients with d-transposition of the great arteries after atrial redirection surgery.

METHODS

This was a retrospective review of semisupine cycle ergometry stress echocardiography performed in 53 patients (64% male; mean age, 24.0 years; 90% Mustard procedure) and 56 healthy control subjects. Incremental exercise to volitional fatigue was performed. Hemodynamic data, echocardiographic cardiac dimensions, area change, tissue Doppler velocities, strain, ventricular synchronization, and superior vena cava flow velocities before and immediately after exercise are reported.

RESULTS

Patients had lower exercise capacity (870 vs 1,854 J/kg, P < .001) and peak heart rates (132 vs 167 beats/min, P < .001). Stroke volume index did not increase with exercise (45 vs 47 mL/m², P = .400). Cardiac index increased in both groups with exercise (3.0 vs 6.1 and 2.9 vs 7.0 L/min/m², P < .001) and was higher in control subjects (P = .006). Right ventricular diastolic and systolic areas decreased significantly with exercise in both the short-axis and four-chamber views. Right and left ventricular contraction time shortened with exercise (405 vs 247 and 338 vs 217 msec, P < .001) and remained synchronous (ratio of right ventricular to left ventricular contraction time = 0.080). Doppler velocities in patients with baffle obstruction were higher in the lower superior vena cava with exercise compared with nonobstructed patients (1.87 vs 1.46 m/sec, P = .020) and normalized after catheter intervention (1.49 vs 1.46 m/sec, P = .800).

CONCLUSIONS

Patients with d-transposition of the great arteries have lower exercise capacity and peak heart rates. The systemic right ventricle presents a lesser but qualitatively normal systolic response and decreased diastolic filling. Semisupine cycle ergometry stress echocardiography unmasked SVC obstruction.

Aortic and Cardiac Structure and Function Using High-Resolution Echocardiography and Optical Coherence Tomography in a Mouse Model of Marfan Syndrome

Marfan syndrome (MFS) is an autosomal-dominant disorder of connective tissue caused by mutations in the fibrillin-1 (FBN1) gene. Mortality is often due to aortic dissection and rupture. We investigated the structural and functional properties of the heart and aorta in a [Fbn1^C1039G/+] MFS mouse using high-resolution ultrasound (echo) and optical coherence tomography (OCT). Echo was performed on 6- and 12-month old wild type (WT) and MFS mice (n = 8). In vivo pulse wave velocity (PWV), aortic root diameter, ejection fraction, stroke volume, left ventricular (LV) wall thickness, LV mass and mitral valve early and atrial velocities (E/A) ratio were measured by high resolution echocardiography. OCT was performed on 12-month old WT and MFS fixed mouse hearts to measure ventricular volume and mass. The PWV was significantly increased in 6-mo MFS vs. WT (366.6 ± 19.9 vs. 205.2 ± 18.1 cm/s; p = 0.003) and 12-mo MFS vs. WT (459.5 ± 42.3 vs. 205.3 ± 30.3 cm/s; p< 0.0001). PWV increased with age in MFS mice only. We also found a significantly enlarged aortic root and decreased E/A ratio in MFS mice compared with WT for both age groups. The [Fbn1^C1039G/+] mouse model of MFS replicates many of the anomalies of Marfan patients including significant aortic dilation, central aortic stiffness, LV systolic and diastolic dysfunction. This is the first demonstration of the direct measurement in vivo of pulse wave velocity non-invasively in the aortic arch of MFS mice, a robust measure of aortic stiffness and a critical clinical parameter for the assessment of pathology in the Marfan syndrome.

Noninvasive Assessment of Vascular Function in Postoperative Cardiovascular Disease (Coarctation of the Aorta, Tetralogy of Fallot, and Transposition of the Great Arteries)

Using noninvasive techniques, we sought to assess arterial stiffness, impedance, hydraulic power, and efficiency in children with postoperative tetralogy of Fallot (TOF), coarctation of the aorta (COA), and transposition of the great arteries (TGAs). Results were compared with those of healthy peers. Fifty-five children with repaired congenital heart disease (24 TOFs, 20 COAs, and 11 TGAs) were compared with 55 age-matched control subjects (CTRL). Echocardiographic Doppler imaging and carotid artery applanation tonometry were preformed to measure aortic flow, dimensions, and calculate pulse wave velocity, vascular impedance and arterial stiffness indexes, hydraulic power (mean and total), and hydraulic efficiency (HE) which were calculated using standard fluid dynamics equations. All congenital heart disease subgroups had higher pulse wave velocity than CTRL. Only the COA group had higher characteristic impedance. Mean power was higher in TGA than in CTRL and TOF, and total power was higher in TGA than in CTRL and TOF. Hydraulic efficiency was higher in TOF than in COA and TGA. In conclusion, children with TOF, COA, and TGA have stiffer aortas than CTRL. These changes may be related to intrinsic aortic abnormalities, altered integrity of the aorta due to surgical repair, and/or acquired postsurgery. These patients may be at increased long-term cardiovascular risk, and long-term follow-up is important for monitoring and assessment of efforts to reduce risk.

Echocardiographic Tests of Left Ventricular Function in Pediatric Cardiology: Are We Searching for the Holy Grail?

In this article the utility of echocardiographic tests of left ventricular (LV) function in pediatric cardiology is reviewed. These indices are derived from the basic concepts of cardiac physiology, namely the Frank-Starling curve, pressure volume loops, and the force frequency relation and, to some extent, are all governed by these general principles. Thus, they are prone to be load-dependent and their utility variable. Methods that use formulas for calculating LV volume are a problem in congenital heart disease in which LV geometry is frequently abnormal. New indices, such as the TEI index, continue to be developed but they are still load-dependent. The utility of more complex LV function tests such as mean velocity of circumferential fibre shortening corrected for heart rate, mean velocity of circumferential fibre shortening corrected for heart rate/wall stress, end-systolic, and arterial elastance also have limitations. Tissue Doppler and its functional derivatives which test myocardial mechanics are being intensively applied to patients with acquired and congenital heart disease. To apply these tests appropriately, knowledge of the strengths, limitations, and variability of each of these tests is required. Resting echocardiograms may mask limited myocardial reserve. Our experience with semisupine cycle ergometry has unmasked limited myocardial reserve and helped in clinical decision-making. Thus, there is no single echocardiographic test that is perfect for all clinical questions. Clinicians must use the appropriate combination of tests to answer the question relevant to individual patients.

Childhood obesity and cardiovascular dysfunction

Obesity-related cardiovascular disease in children is becoming more prevalent in conjunction with the rise in childhood obesity. Children with obesity are predisposed to an increased risk of cardiovascular morbidity and mortality in adulthood. Importantly, research in children with obesity over the last decade has demonstrated that children may exhibit early signs of cardiovascular dysfunction as a result of their excess adiposity, often independent of other obesity-related comorbidities such as dyslipidemia and insulin resistance. The clinical evidence is accumulating to suggest that the cardiovascular damage, once observed only in adults, is also occurring in obese children. The objective of this review is to provide a synopsis of the current research on cardiovascular abnormalities in children with obesity and highlight the importance and need for early detection and prevention programs to mitigate this potentially serious health problem.

Physical activity recommendations for patients with electrophysiologic and structural congenital heart disease: a survey of Canadian health care providers

Determining safe levels of physical activity for children and adolescents with electrophysiologic and structural congenital heart disease is a challenging clinical problem. The body of evidence for making these recommendations is limited and likely based on expert opinion, medicolegal concerns, and perceived risks of sudden cardiac death (SCD) with activity. The Bethesda Conference has established consensus guidelines for determining the eligibility of athletes with cardiovascular abnormalities for competitive sports and their disqualification from them. However, literature on guidelines for noncompetitive physical activity is not available. A survey was designed to determine practice patterns for patients with electrophysiologic and structural congenital heart disease. Between July 2011 and December 2011, approximately 350 health care providers working with this group of patients were recruited by email or while attending professional meetings. The survey received 81 responses, primarily from pediatric cardiologists (70 %). The findings indicate that the majority of Canadian cardiac care providers surveyed are only partially implementing current recommendations. Areas of variance included physical activity recommendations for hypertrophic cardiomyopathy, long QT syndrome, catecholaminergic polymorphic ventricular tachycardia, and heart transplantation, among others. The development of comprehensive consensus guidelines for activity recommendations was supported by 96 % of the respondents. The heterogeneity of responses may be attributable to conflicting and poorly evidenced information in the literature, a lack of emphasis on recreational activity, an entrenched tendency toward bed rest in the cardiology community, and a lack of awareness by cardiac care providers regarding the actual risk associated with physical activity in electrophysiologic and structural congenital heart disease. A balanced discussion is required in considering both the significant benefit of physical activity in reducing cardiovascular risk factors and the small possibility of SCD in children and young adults with electrophysiologic and structural congenital heart disease.

Echo-Doppler assessment of the biophysical properties of the aorta in children with chronic kidney disease

Chronic kidney disease (CKD) is known to cause increased arterial stiffness, which is an important independent risk factor for adverse cardiovascular events. The purpose of this study was to assess the vascular properties of the aorta (AO) in a group of children with CKD using a noninvasive echocardiography (echo)-Doppler method. We studied 24 children with stages 2 through 5 CKD and 48 age-matched controls. Detailed echocardiographic assessment and echo-Doppler pulse wave velocity (PWV) was performed. Indices of arterial stiffness, including characteristic (Zc) and input (Zi) impedances, elastic pressure-strain modulus (Ep), and arterial wall stiffness index, were calculated. CKD patients underwent full nephrology assessment, and an iohexol glomerular filtration rate was performed, which allowed for accurate assignment of the CKD stage. CKD patients had greater median systolic blood pressure (114 vs. 110 mmHg; p < 0.04) and pulse pressure (51 vs. 40 mmHg; p < 0.001) compared with controls. PWV was similar between groups (358 vs. 344 cm s(-1); p = 0.759), whereas Zi (182 vs. 131 dyne s cm(-5); p < 0.001), Zc (146 vs. 138 dyne s cm(-5); p = 0.05), and Ep (280 vs. 230 mmHg; p < 0.02) were significantly greater in CKD than in controls. Although load-dependent measures of arterial stiffness were greater in non-dialysis dependent CKD patients, PWV was not increased compared with controls. This suggests that the increased arterial stiffness may not be permanent in these pediatric patients with kidney disease.

Anthracycline induced cardiac toxicity in pediatric Ewing sarcoma: a longitudinal study

BACKGROUND

Reports on incidence and factors associated with anthracycline cardiotoxicity in patients with Ewing sarcoma vary and few studies evaluate effect over time. Longitudinal trends in cardiac function and prognostic value of % decline in ejection fraction (EF) during therapy have not been previously described in Ewing sarcoma.

PROCEDURE

A retrospective review of patients age <17 years, diagnosed with Ewing sarcoma during 1978-2006, treated at British Columbia Children's Hospital with anthracycline chemotherapy was undertaken. Echocardiograms performed pre-treatment, worst function during treatment, on therapy completion; worst function during surveillance and the most recent echocardiogram were reviewed. Cardiac toxicity was graded using Common Terminology Criteria for Adverse Events v 3.0 and 4.0.

RESULTS

Among 71 eligible patients, median age at diagnosis 11.1 years, median cumulative dose of anthracycline was 365 mg/m2 . There were 397 echocardiograms with 153 (39%) abnormal. There were 21/71 patients with EF < 50%, 11 with EF < 40% and five cardiac deaths including 2/3 patients post-cardiac transplant. The median time to worst cardiac function was 51 months. Post-therapy completion 16/71 patients with progressive decline in cardiac function were noted. No patient with 10-15% decline in EF during therapy developed cardiotoxicity. Younger age (P = 0.004) and low BMI (P = 0.034) as continuous variables with anthracycline administration by IV push (P = 0.03) were risk factors for cardiotoxicity on univariate analysis but not significant within logistic regression models.

CONCLUSIONS

The high incidence of cardiotoxicity associated with higher administered anthracycline dose, young age, bolus infusion, and EF decline warrants evaluation in a larger cohort.

Postnatal outcome in patients with fetal tachycardia

The diagnosis and management of prenatal tachyarrhythmias is well established; however, the postnatal course and outcomes are not. The purpose of our study was to review the natural history of patients with fetal tachycardia, determine the incidence of postnatal arrhythmias, and determine whether there are factors to predict which fetuses will develop postnatal arrhythmias. A retrospective chart review of patients with fetal tachyarrhythmias investigated at British Columbia Children's and Women's Hospitals between 1983 and 2010 was conducted. Sixty-nine mother-fetus pairs were eligible for the study. Fifty-two had fetal supraventricular tachycardia, and 17 had fetal atrial flutter. Conversion to sinus rhythm occurred prenatally in 52 % of patients. Postnatal arrhythmia occurred in two thirds of patients, with 82 % of those cases occurring within the first 48 h of life. Hydrops fetalis, female sex, and lack of conversion to sinus rhythm was predictive of postnatal arrhythmia (P = 0.01, P = 0.01, and P = 0.001, respectively). Conversion to sinus rhythm prenatally did not predict postnatal arrhythmia. Median duration of treatment was 9 months. Two postnatal deaths of unknown etiology occurred. Two thirds of all patients with prenatal tachycardia will develop postnatal arrhythmia. Prenatal factors that predict postnatal arrhythmia include hydrops, sex, and whether or not conversion to sinus rhythm occurred prenatally. The majority of patients with postnatal arrhythmia present within 48 h of life, which has clinical implications for monitoring. Postnatal outcome is generally very good with most patients being weaned off medication in 6-12 months.

Population-based review of tetralogy of Fallot with absent pulmonary valve: is prenatal diagnosis really associated with a poor prognosis?

OBJECTIVES

Tetralogy of Fallot with absent pulmonary valve syndrome (TETAPV) is reported in obstetric literature to have an extremely poor prognosis. We sought to determine the clinical outcome associated with TETAPV and whether prenatal diagnosis confers a poor prognosis.

METHODS

All cases of TETAPV diagnosed in British Columbia between 1980 and 2009 were reviewed and grouped according to time of diagnosis, either prenatal or postnatal. The groups were compared with respect to mortality, respiratory problems, number of interventions and functional capacity at last follow-up.

RESULTS

Eight and 11 patients were included in the prenatally and postnatally diagnosed groups, with overall long-term survival of 71% and 82%, respectively. There was no significant difference in mortality, frequency of preoperative intubation, number of interventions or functional capacity between groups.

CONCLUSION

From a population-based retrospective analysis of TETAPV cases identified over three decades it is concluded that the prognosis for TETAPV is better than that previously reported in the obstetric literature. This information should be used to guide prenatal counseling.

Serial measurements of exercise performance in pediatric heart transplant patients using stress echocardiography

Heart transplantation is an increasingly acceptable therapeutic option for children with end-stage and complex congenital heart disease. With advances in surgery, immunosuppression, and follow-up care, functional outcomes need to be evaluated. We report the results of serial exercise testing performed using stress echocardiography in a cohort of pediatric HTP. HTP (n = 7) exercised on a semi-recumbent ergometer to volitional fatigue. Echocardiography-Doppler measurements, HR, and blood pressure were taken at rest and during staged exercise. Results were compared with healthy CON (n = 12). HTP did significantly less work during exercise (940 vs. 1218 J/kg, p < 0.03). Their SVI (33 vs. 49 mL/m(2), p < 0.003), CI (5.16 vs. 9.25 L/min/m(2), p < 0.0005), and HR (162 vs. 185 bpm, p < 0.02) were lower at peak exercise. HTP had a lower SF at peak exercise (48% vs. 52%, p < 0.03) and an abnormal relationship between the MVCFc and σPS. During follow-up, hemodynamics and left ventricular function remained relatively constant in HTP. HTP are able to exercise safely; however, their exercise tolerance is reduced, and hemodynamics and contractility are diminished. Over time, their hemodynamics and left ventricular function have remained relatively constant.

Primary pulmonary arterial hypertension and autoimmune polyendocrine syndrome in a pediatric patient

Both primary pulmonary artery hypertension (PPAH) and autoimmune polyendocrine syndrome (APS) are rare disorders in children. We report a boy who was diagnosed with severe PPAH at 12 years of age. He was treated with prostacyclin for 6 years, briefly with adjunct bosentan, and eventually sildenafil was added. Six years later, after his diagnosis of PPAH, he developed APS in the form of hyperthyroidism and type 1 diabetes mellitus. No mutations were identified through genetic testing of bone morphogenetic protein receptor type II and the autoimmune-regulator gene. To our knowledge this is the first description of the combination of these two extremely rare diseases in a child.

Early changes in the biophysical properties of the aorta in pre-adolescent children born small for gestational age

OBJECTIVE

To assess the biophysical properties of the aorta in children born small for gestational age (SGA) with an echo-Doppler method and to determine associations with known perinatal risk factors.

STUDY DESIGN

In this cross-sectional study, 39 SGA and 41 control subjects aged 8 to 13 years were recruited. Perinatal risk factors were recorded. The aortic diameters and pulse wave transit time around the aortic arch were measured with echo-Doppler and the blood pressure recorded. Pulse wave velocity, aortic input impedance (Zi), characteristic impedance (Zc), arterial pressure-strain elastic modulus (Ep), and arterial wall stiffness index (beta-index) were calculated.

RESULTS

Pulse wave velocity (374 +/- 46 vs 348 +/- 47 cm/sec, P < .02); Zi (177 +/- 39 vs 142 +/- 27 dynes x sec/cm(5), P < .0001); Zc (185 +/- 29 vs 152 +/- 37 dynes x sec/cm(5), P < .0001); Ep (286 +/- 101 vs 216 +/- 41 mm Hg, P < .0001); and beta-index (2.43 +/- 0.32 vs 2.17 +/- 0.15, P < .0001) were all higher in SGA. We found negative associations between the following: birth weight and Zi, Zc, Ep, and beta-index; as well as body mass index and Zi, Zc.

CONCLUSION

This simple echo-Doppler method demonstrated abnormal biophysical properties of the aorta in a cohort of pre-adolescent patients born SGA who remain small in stature and continue to have normal blood pressure.

Does biventricular pacing improve hemodynamics in children undergoing routine congenital heart surgery?

Biventricular (BiV) pacing or cardiac resynchronization therapy (CRT) is an established therapy for heart failure in adults. In children, cardiac dyssynchrony occurs most commonly following repair of congenital heart disease (CHD) where multisite pacing has been shown to improve both hemodynamics and ventricular function. Determining which patient types would specifically benefit has not yet been established. A prospective, repeated measures design was undertaken to evaluate BiV pacing in a cohort of children undergoing biventricular repair for correction of their CHD. Hemodynamics, arterial blood gas, electrocardiographic (ECG), and echocardiographic data were collected. Pacing protocol was undertaken prior to the patient's extubation with 20 min of conventional right ventricular (RV) or BiV pacing, preceded and followed by 10 min of recovery time. Multivariate statistics were used to analyze the data with p values <0.05 considered significant. Twenty-five (14 female) patients underwent surgery at a median (range) age of 5.2 (0.1-37.4) months with no early mortality. The Risk-adjusted classification for Congenital Heart Surgery (RACHS) scores were 2 in 14 patients, 3 in eight patients, and 4 in three patients. None had pre-existing arrhythmias, dyssynchrony, or required pacing pre-operatively. No patient required implantation of a permanent pacemaker post-operatively. The median cardio-pulmonary bypass time was 96 (55-236) min. RV and BiV pacing did not improve cardiac index from baseline (3.23 vs. 3.42 vs. 3.39 L/min/m2; p > 0.05). The QRS duration was not changed with pacing (100 vs. 80 vs. 80 ms; p > 0.05). On echocardiography, the time-to-peak velocity difference between the septal and posterior walls (synchrony) during pacing was similar to baseline and was also not statistically significant. BiV pacing did not improve cardiac output when compared to intrinsic sinus rhythm or RV pacing in this cohort of patients. Our study has shown that BiV pacing is not indicated in children who have undergone routine BiV congenital heart surgery. Further prospective studies are needed to assess the role of multisite pacing in children with ventricular dyssynchrony such as those with single ventricles, those undergoing reoperation or those with high RACHS scores.

A novel method to estimate the aortic pressure waveform using B-mode ultrasound images acquired from a suprasternal view

A novel method to obtain the aortic pressure waveform using a sequence of B-mode images is developed in this project. An automatic edge detection algorithm is applied to a sequence of longitudinal images of the aortic arch acquired from a suprasternal view. The aortic distension waveform is obtained by measuring the distance between the two edges throughout the cardiac cycle. It is then calibrated using the systolic and diastolic pressures from the brachial artery to obtain an estimated pressure waveform. This method was applied to 5 healthy children, pulse pressure amplification and total arterial compliance were calculated from the estimated waveforms.

Loss of elastic fiber integrity and reduction of vascular smooth muscle contraction resulting from the upregulated activities of matrix metalloproteinase-2 and -9 in the thoracic aortic aneurysm in Marfan syndrome

Thoracic aortic aneurysm (TAA) is the life-threatening complication of Marfan syndrome (MFS), a connective tissue disorder caused by mutations in the fibrillin-1 gene. TAA is characterized by degradation of elastic fiber, suggesting the involvement of matrix metalloproteinase (MMP)-2 and -9, the activation of which is regulated by TIMP (tissue inhibitor of MMP) types 1 and 2. We hypothesized that MMP-2 and -9 were upregulated during TAA formation in Marfan syndrome, causing loss of elastic fibers and structural integrity. We studied mice, from 3 to 12 months, heterozygous for a mutant Fbn1 allele encoding a cysteine substitution in fibrillin-1 (Fbn1(C1039G/+), designated as "Marfan" mice) (n=120), the most common class of mutation in Marfan syndrome. The littermates, Fbn1(+/+) served as controls (n=120). In Marfan aneurysmal thoracic aorta, mRNA and protein expression of MMP-2 and -9 were detected at 3 months and peaked at 6 months of age, accompanied by severe elastic fiber fragmentation and degradation. From 3 to 9 months, the MMP-2/TIMP-2 ratio increased by 43% to 63% compared with the controls. Dilated thoracic aorta demonstrated increased elasticity but distention caused a pronounced loss of contraction, suggesting weakening of the aortic wall. Breaking stress of the aneurysmal aorta was 70% of the controls. Contraction in response to depolarization and receptor stimulation decreased in the aneurysmal thoracic aorta by 50% to 80%, but the expression of alpha-smooth muscle actin between the 2 strains was not significantly different. This report demonstrates the upregulation of MMP-2 and -9 during TAA formation in Marfan syndrome. The resulting elastic fiber degeneration with deterioration of the aortic contraction and mechanical properties may explain the pathogenesis of TAA.

A population-based study of cardiac malformations and outcomes associated with dextrocardia

The incidence of dextrocardia and its associated cardiac and noncardiac malformations is not known. There is inadequate information about outcomes to counsel parents about prognosis. A retrospective review of all diagnoses of dextrocardia due to embryologic development at a tertiary care hospital from 1985 to 2001 was performed. Eighty-one cases were identified (48 antenatally). The incidence of dextrocardia was estimated to be 1 in 12,019 pregnancies. Twenty-seven cases were situs solitus, 30 situs inversus, and 24 situs ambiguous or isomerism. Cardiac malformations were found in 26 of 27 cases of situs solitus, 7 of 30 cases of situs inversus, and 24 of 24 cases of isomerism. Noncardiac malformations were identified in 10 of 27 cases of situs solitus, 6 of 30 cases of situs inversus, and 14 of 24 cases of isomerism. Twelve pregnancies were terminated, 3 fetuses were stillborn, and 2 women chose compassionate care. All terminated fetuses were diagnosed with dextrocardia before termination, and all had >1 cardiac anomaly; 7 also had noncardiac anomalies. There were 43 subjects in the intention-to-treat group (20 situs solitus, 10 solitus inversus, 13 isomerism). Thirty-two had >or=1 cardiac operation, and 21 had >or=3. Thirty-nine subjects were alive at most recent follow-up. In conclusion, the incidence of dextrocardia was 1 in 12,019 pregnancies. In conclusion, in our cohort, the numbers of cases of situs solitus, situs inversus, and isomerism were similar. Cardiac and noncardiac malformations were most common in the isomerism group. Cardiac malformations were often complex in the situs solitus and isomerism groups. Ninety-one percent of those in the intention-to-treat cohort were alive at follow-up.

A stress echocardiography study of cardiac function during progressive exercise in pediatric oncology patients treated with anthracyclines

BACKGROUND

Anthracycline-treated patients (AP) are at risk for cardiac dysfunction years after treatment. Cardiac function has not been evaluated during exercise in AP. The purpose of this study was to assess exercise tolerance, left ventricular (LV) function, and hemodynamics during progressive exercise.

PROCEDURE

We studied 47 AP (cumulative dose: 36-504 mg/m(2)) who were in complete remission and 12 healthy controls (CON). AP were further grouped by cumulative dose (LOW <or= 260 mg/m(2); HIGH >or= 260 mg/m(2)) and resting echocardiographic function. All subjects performed 3-min incremental stages on a semi-recumbent cycle ergometer until volitional fatigue. Using echocardiography and Doppler, LV dimensions, posterior wall thickness (LVPWs), peak aortic velocity (PAoV), shortening fraction (SF), rate-corrected mean velocity of fiber shortening (MVCFc), wall stress at peak systole (sigmaPS), stroke volume index (SVI), and cardiac index (CI) were determined. Measurements were performed at rest, during each stage of exercise, and in recovery.

RESULTS

AP did less work than CON (P < 0.050). CON and LOW had similar resting function, while HIGH had a lower SF and MVCFc (P < 0.050) and a higher sigmaPS (P < 0.001). Resting SVI and CI were also lower in HIGH. At peak exercise, MVCFc and sigmaPS remained different in HIGH, and both AP groups had a lower SF, SVI, and CI (P < 0.001). AP had an abnormal SVI response to exercise. AP showed a smaller initial increase in SVI that was not maintained throughout exercise.

CONCLUSIONS

AP have reduced exercise tolerance. There also appears to be a dose-related effect on myocardial contractility and SVI. These findings may help to guide treatment.

Endothelial dysfunction and compromised eNOS/Akt signaling in the thoracic aorta during the progression of Marfan syndrome

BACKGROUND AND PURPOSE

Aortic complications account for the major mortality in Marfan syndrome (MFS), a connective tissue disorder caused by mutations in FBN1 encoding fibrillin-1. We hypothesized that MFS impaired endothelial function and nitric oxide (NO) production in the aorta.

EXPERIMENTAL APPROACH

Mice (at 3, 6, 9 and 12 months of age) heterozygous for the Fbn1 allele encoding a cysteine substitution (Fbn1 (C1039G/+), Marfan mice, n=75), the most common class of mutation in MFS, were compared with age-matched control littermates (n=75). Thoracic and abdominal aortas from the two groups were studied.

KEY RESULTS

Isometric force measurements revealed that relaxation to ACh (but not to sodium nitroprusside) was diminished in the phenylephrine-precontracted Marfan thoracic aorta at 6 months of age (pEC(50)=6.12+/-0.22; maximal response, E(max)=52.7+/-6.8%; control: pEC(50)=7.34+/-0.19; E(max)=84.8+/-2.2%). At one year, both inhibition of NO production with N(omega)-nitro-L-arginine methyl ester, or denudation of endothelium increased the phenylephrine-stimulated contraction in the control thoracic aorta by 35%, but had no effect in the Marfan aorta, indicating a loss of basal NO production in the Marfan vessel. From 6 months, a reduced phosphorylation of endothelial NOS (eNOS)(Ser1177) and Akt(Thr308) detected by Western blotting was observed in the Marfan thoracic aorta, which was accompanied by decreased levels of cGMP. Expressions of Akt and eNOS in the abdominal aorta were not different between the two groups.

CONCLUSIONS AND IMPLICATIONS

MFS impairs endothelial function and signaling of NO production in the thoracic aorta, suggesting the importance of NO in the age-related progression of thoracic aortic manifestations.

Intra-atrial thrombus in a neonate with coarctation of the aorta

It is uncommon for thrombus to form within the heart of neonates with congenital cardiac disease. We describe a newborn with coarctation of the aorta, in whom a left atrial thrombus was discovered on the second day of life, and was thought to have been present before birth.

Right-sided cardiac involvement in osteogenesis imperfecta

Skeletal manifestations are the hallmark of the osteogenesis imperfecta group of disorders. Extraskeletal involvement may, however, contribute significantly to morbidity. Structural cardiovascular anomalies reported in osteogenesis imperfecta include aortic root dilatation and aortic and mitral valve dysfunction. Herein is reported the first case of involvement of the right side of the heart in osteogenesis imperfecta.

Echocardiographic Doppler assessment of the biophysical properties of the aorta in pediatric patients with the Marfan syndrome

In the Marfan syndrome (MS), aortic root involvement is usually clinically monitored according to the aortic sinus of Valsalva dilation. Using an echocardiographic Doppler method in this cross-sectional study, abnormal biophysical properties of the ascending aorta were found in pediatric patients with MS compared with healthy controls but not consistently in association with the aortic sinus of Valsalva dilation.

Diagnosis of fetal ductus arteriosus aneurysm: importance of the three-vessel view

OBJECTIVE

To present four cases of ductus arteriosus aneurysm (DAA) detected by fetal echocardiography and highlight the value of the three-vessel view in the diagnosis of DAA.

METHODS

In addition to the standard fetal echocardiographic views, we examined the three-vessel view in four cases of DAA. The three-vessel view was achieved by sliding the transducer cranially from the four-chamber plane toward the fetal upper mediastinum to demonstrate cross-sections of the main pulmonary artery, the ascending aorta and superior vena cava arranged in a straight line from the left anterior to the right posterior aspect of the mediastinum. DAA was diagnosed when there was a tortuous ductus arteriosus with a dilation that protruded leftward of the aortic arch.

CASE SERIES

In the first case, an insulin-dependent diabetic woman underwent fetal ultrasound examination at 36 weeks' gestation showing right-to-left cardiac disproportion and bidirectional flow in the aorta and main pulmonary artery (PA). The three-vessel view showed a dilated ductus arteriosus (DA) which was stenosed at its distal end. In the second case, a woman had fetal ultrasound scans at 38 and 39 weeks' gestation for suspected intrauterine growth restriction and oligohydramnios. The scans identified an abnormal aortic arch and the three-vessel view showed an elongated vascular structure at the distal end of the PA, which was the DAA. In the third case, a woman with a high-risk obstetric history had multiple scans showing an abnormal PA to aorta relationship, with an apparent 'kink' in the PA. The three-vessel view clarified that this was the DAA. In the fourth case, a woman was scanned because of a 3-kg weight gain in 1 week. The fetal ultrasound scan showed moderate polyhydramnios with normal fetal growth and normal intracardiac anatomy and flow, and the three-vessel view demonstrated a large DA. In each of these cases, the DAA appeared to have occurred in isolation with non-specific clinical findings.

CONCLUSION

We advocate the use of the three-vessel view, in conjunction with the standard echocardiography views currently employed, to assist in the diagnosis of DAA.

Repair in infancy of right aortic arch with aberrant left brachiocephalic artery in the setting of a variant of the hypoplastic left heart syndrome

A right aortic arch, with a retroesophageal transverse arch and an aberrant left brachiocephalic artery, is a rare anomaly by itself. When combined with severe mitral stenosis and hypoplasia of the left ventricle, it is rarer still. We describe the diagnosis and treatment of this rare anomaly in an infant using a modification of the Norwood operation.

Diagnosis and outcome of dextrocardia diagnosed in the fetus

A retrospective review of 5,539 fetal echocardiograms over a 22-year period revealed 85 cases of dextrocardia. In primary dextrocardia (46 cases), the incidence of situs solitus, inversus, and ambiguous, was similar and associated with a high incidence of complex cardiac malformations in situs solitus and situs ambiguous. Secondary dextrocardia (39 cases) was due to intrathoracic displacement and, when caused by diaphragmatic hernia, was associated with cardiac malformations in 31% of cases. Even in complex cases, fetal echocardiography was highly accurate; therefore, specific counseling can be given to parents.

Pulmonary atresia with intact ventricular septum and antenatal left ventricular failure

Pulmonary atresia with intact ventricular septum has been described extensively, and it is recognized that associated abnormalities of the coronary arteries may cause ischemia. We describe a fetus, diagnosed antenatally as having pulmonary atresia with intact ventricular septum and severe hypoplasia of the right ventricle, who developed severe left ventricular dysfunction. We hypothesize that this is due to reduced coronary blood flow because of falling right ventricular volume in the presence of complete right ventricular coronary arterial dependence.

Myocardial contractility in premature neonates with and without patent ductus arteriosus

Controversy exists as to whether a hemodynamically significant left-to-right shunt due to a patent ductus arteriosus (PDA) affects ventricular contractility. Load-dependent indices such as ejection fraction and shortening fraction have traditionally been used to assess contractility, but the relationship between the rate-corrected velocity of fiber shortening (MVCFc) and wall stress may be more suitable, as it is a preload-independent, afterload-adjusted method of assessing ventricular contractility. Age-related differences have been established for these variables in normal adults and children and it has been recommended for use in the premature neonate. The study was performed to assess left ventricular contractility in premature neonates with a significant left-to-right shunt due to a PDA. Using echocardiography, we measured the relationship of MVCFc to stress at peak systole (SPS) in two groups of premature infants. Group 1 consisted of 15 controls (680-1495 g, 25-32 weeks' gestation), and Group 2 of 15 neonates with hemodynamically significant PDA (840-1635 g, 26-33 weeks' gestation). In both groups, MVCFc was linearly and inversely related to SPS ( p < 0.001). The regression equations were as follows: Group 1, MVCFc = -0.0153SPS + 1.70 ( R(2) = 0.68); and Group 2, MVCF = - 0.019SPS + 1.89 ( R(2) = 0.76). There was no significant difference in the relationship between the two groups, but their slopes were significantly steeper and had a higher Y-intercept than the relationship we previously reported for older children. This preliminary study establishes the normal MVCFc/SPS relationship in the premature neonate (25-33 weeks' gestation) and suggests that premature infants function at a higher resting contractile state than older children. A hemodynamically significant PDA has no effect on contractility. These data will be useful in assessing left ventricular contractility in premature neonates with other types of ventricular loading and noncardiac stress.

A novel Doppler echocardiographic method of measuring the biophysical properties of the aorta in pediatric patients

BACKGROUND

This study was performed to: (1) assess the feasibility of measuring pulse wave velocity (PWV) from aortic (AO) Doppler flow and deriving AO input and characteristic impedances and the arterial pressure strain elastic modulus; and (2) compare these indices in pediatric patients with arterial disease to control (C) patients.

METHODS

There were 14 healthy children in the C group, 9 with inflammatory connective tissue diseases (ICTD), and 6 with Marfan syndrome (M). Using standard echocardiographic equipment, the AO annulus, AO root diameter in systole (AO(S)) and diastole (AO(D)), and AO length (L) were measured. The time taken for the Doppler signal to travel from the ascending to descending aorta was measured. AO peak flow was calculated from AO annulus cross-sectional area x peak aortic velocity (AoV); PWV = L/time taken for the Doppler signal to travel from the ascending to descending aorta; input impedance = (systolic - diastolic blood pressure)/(AO cross-sectional area x AoV); characteristic impedance = (PWV x rho)/Ao cross-sectional area (where rho = 1.06); and pressure strain elastic modulus = (systolic - diastolic blood pressure)/[(AO(S) - AO(D))/AO(D)]; beta index = ln (systolic/diastolic blood pressure)/[(AO(S) - AO(D))/AO(D)].

RESULTS

Results for PWV were ICTD = M > C (533, 496, 362 cm/s; P <.02); for input impedance were ICTD > M = C (245, 120, 116; P <.03); for characteristic impedance were ICTD < M = C (249, 107, 142; P <.05); for pressure strain elastic modulus were M > ICTD = C (262, 447, 187; P <.003); and for beta index were M > ICTD > C (2.91, 2.51, 2.13; P <.0006).

CONCLUSIONS

This novel, relatively simple method of assessing the biophysical properties of the aorta shows abnormal function in patients with M and ICTD. This technique may be helpful in the long-term follow up of patients with arterial disease.

Coronary arterial abnormalities in pulmonary atresia with intact ventricular septum diagnosed during fetal life

OBJECTIVES

To establish the prevalence of coronary arterial abnormalities in mid-trimester fetuses with pulmonary atresia with intact ventricular septum, and whether their presence correlates with right ventricular morphology.

BACKGROUND

The presence of coronary arterial fistulas significantly alters the surgical options and prognosis for patients with pulmonary atresia with intact ventricular septum. The lesion can reliably be diagnosed using fetal echocardiography, and further definition of the prognosis is important for counselling parents.

METHODS

We examined the hearts of 39 pathological specimens diagnosed during fetal life, 3 of whom died postnatally. Coronary arterial abnormalities were defined as non-connection of the left or right coronary arteries to the aorta, ostial stenosis, marked tortuosity, dilation, thickening or abnormal myocardial branching. Mild tortuosity, or myocardial bridging, were considered normal. We measured the dimensions of the tricuspid valve along with the inlet and outlet portions of the ventricles. Ebstein's malformation, tricuspid valvar dysplasia, and the presence or absence of the infundibulum, were especially noted. We examined also 12 normal hearts as controls.

RESULTS

Coronary arterial abnormalities were found in 14/39 (36%). The dimensions of the right ventricle and tricuspid valves, and the gestational ages of the fetuses, were compared for these 14 with the 25 having no abnormalities using independent t-tests. The gestational ages were similar, 21.9 vs 21.1 weeks. The mean dimensions of the tricuspid valve, median z-scores, and right ventricle were smaller, 2.9 vs 7.2 mm; p < 0.002; -4.46 vs 0.23; p < 0.03; and 6.9 vs 13.7 mm; p < 0.002, for those with coronary arterial abnormalities. Ebstein's malformation, or dysplasia of the tricuspid valve, was present in 4 of 14 with, vs 15 of 25 without, coronary arterial abnormalities. A patent infundibulum was noted in 34 of 39 specimens.

CONCLUSIONS

Mid-trimester fetuses with pulmonary atresia with intact ventricular septum already exhibit coronary arterial abnormalities, with a prevalence of 36%. The presence of a patent infundibulum confirms that atresia of the pulmonary valve is an acquired process. Coronary arterial abnormalities are seen in 50% of those with hypoplastic right ventricles, but less frequently in the presence of well developed ventricles. This is important information for those involved in counselling parents.

Pulmonary atresia with intact ventricular septum: range of morphology in a population-based study

OBJECTIVES

We describe the morphologic variability in pulmonary atresia with intact ventricular septum (PAIVS) within a population-based study.

BACKGROUND

An uncommon disease, PAIVS shows considerable morphologic heterogeneity. Clinical reports, based mostly on small samples of patients, may not reflect the true spectrum of pathology of this condition. We have studied the entire range of morphology in a prospective population-based study of patients over a five-year period (1991 to 1995). METHODS; As part of the United Kingdom and Ireland Collaborative Study of PAIVS, all 18 pediatric cardiac centers were visited by a single investigator. Morphologic features of each case were determined by direct review of the echocardiograms and angiocardiograms, from surgical and autopsy reports, and by review of pathology specimens where available.

RESULTS

Among 183 live-born infants, atresia was valvar (membranous) in 74.7% and muscular in 25.3%. Muscular obliteration of the apical trabecular cavity, and in some cases its infundibulum, resulted in "bipartite" right ventricle (RV) in 33.6%, and a "unipartite" chamber in 7.7%. The remaining 58.7% had "tripartite" morphology. Coronary arterial abnormalities were identified in 45.8%, including arterial stenoses, interruptions and ectasia in 7.6%. Ebstein's malformation coexisted in 18 patients. Median tricuspid valvar size and RV inlet Z-scores were -5.2 and -5.1, respectively.

CONCLUSIONS

This study provides unique data on the diverse pathology of PAIVS in an unselected population. This will help determine if published reports reflect the true spectrum of pathology of the condition.