Sally-Ann B. Clur

Pediatric Pulmonary Hypertension in the Netherlands Epidemiology and Characterization During the Period 1991 to 2005

Background— Incidence and prevalence rates for pediatric pulmonary hypertension (PH) and pulmonary arterial hypertension (PAH) are unknown. This study describes the nationwide epidemiological features of pediatric PH in the Netherlands during a 15-year period and the clinical course of pediatric PAH. Methods and Results— Two registries were used to retrospectively identify children (0–17 years) with PH. Overall, 3263 pediatric patients were identified with PH due to left heart disease (n=160; 5%), lung disease/hypoxemia (n=253; 8%), thromboembolic disease (n=5; <1%), and transient (n=2691; 82%) and progressive (n=154; 5%) PAH. Transient PAH included persistent PH of the newborn and children with congenital heart defects (CHD) and systemic-to-pulmonary shunt, in whom PAH resolved after successful shunt correction. Progressive PAH mainly included idiopathic PAH (n=36; iPAH) and PAH associated with CHD (n=111; PAH-CHD). Pulmonary arterial hypertension associated with CHD represented highly heterogeneous subgroups. Syndromes were frequently present, especially in progressive PAH (n=60; 39%). Survival for PAH-CHD varied depending on the subgroups, some showing better and others showing worse survival than for iPAH. Survival of children with Eisenmenger syndrome appeared worse than reported in adults. For iPAH and PAH-CHD, annual incidence and point prevalence averaged, respectively, 0.7 and 4.4 (iPAH) and 2.2 and 15.6 (PAH-CHD) cases per million children. Compared to studies in adults, iPAH occurred less whereas PAH-CHD occurred more frequently. Conclusions— Pediatric PH is characterized by various age-specific diagnoses, the majority of which comprise transient forms of PAH. Incidence of pediatric iPAH is lower whereas incidence of pediatric PAH-CHD is higher than reported in adults. Pediatric PAH-CHD represents a heterogeneous group with highly variable clinical courses. # Clinical Perspective {#article-title-25}Background— Incidence and prevalence rates for pediatric pulmonary hypertension (PH) and pulmonary arterial hypertension (PAH) are unknown. This study describes the nationwide epidemiological features of pediatric PH in the Netherlands during a 15-year period and the clinical course of pediatric PAH. Methods and Results— Two registries were used to retrospectively identify children (0–17 years) with PH. Overall, 3263 pediatric patients were identified with PH due to left heart disease (n=160; 5%), lung disease/hypoxemia (n=253; 8%), thromboembolic disease (n=5; <1%), and transient (n=2691; 82%) and progressive (n=154; 5%) PAH. Transient PAH included persistent PH of the newborn and children with congenital heart defects (CHD) and systemic-to-pulmonary shunt, in whom PAH resolved after successful shunt correction. Progressive PAH mainly included idiopathic PAH (n=36; iPAH) and PAH associated with CHD (n=111; PAH-CHD). Pulmonary arterial hypertension associated with CHD represented highly heterogeneous subgroups. Syndromes were frequently present, especially in progressive PAH (n=60; 39%). Survival for PAH-CHD varied depending on the subgroups, some showing better and others showing worse survival than for iPAH. Survival of children with Eisenmenger syndrome appeared worse than reported in adults. For iPAH and PAH-CHD, annual incidence and point prevalence averaged, respectively, 0.7 and 4.4 (iPAH) and 2.2 and 15.6 (PAH-CHD) cases per million children. Compared to studies in adults, iPAH occurred less whereas PAH-CHD occurred more frequently. Conclusions— Pediatric PH is characterized by various age-specific diagnoses, the majority of which comprise transient forms of PAH. Incidence of pediatric iPAH is lower whereas incidence of pediatric PAH-CHD is higher than reported in adults. Pediatric PAH-CHD represents a heterogeneous group with highly variable clinical courses.

Comparison of Transplacental Treatment of Fetal Supraventricular Tachyarrhythmias With Digoxin, Flecainide, and Sotalol Results of a Nonrandomized Multicenter Study

Background— Fetal tachyarrhythmia may result in low cardiac output and death. Consequently, antiarrhythmic treatment is offered in most affected pregnancies. We compared 3 drugs commonly used to control supraventricular tachycardia (SVT) and atrial flutter (AF). Methods and Results— We reviewed 159 consecutive referrals with fetal SVT (n=114) and AF (n=45). Of these, 75 fetuses with SVT and 36 with AF were treated nonrandomly with transplacental flecainide (n=35), sotalol (n=52), or digoxin (n=24) as a first-line agent. Prenatal treatment failure was associated with an incessant versus intermittent arrhythmia pattern (n=85; hazard ratio [HR]=3.1; P<0.001) and, for SVT, with fetal hydrops (n=28; HR=1.8; P=0.04). Atrial flutter had a lower rate of conversion to sinus rhythm before delivery than SVT (HR=2.0; P=0.005). Cardioversion at 5 and 10 days occurred in 50% and 63% of treated SVT cases, respectively, but in only 25% and 41% of treated AF cases. Sotalol was associated with higher rates of prenatal AF termination than digoxin (HR=5.4; P=0.05) or flecainide (HR=7.4; P=0.03). If incessant AF/SVT persisted to day 5 (n=45), median ventricular rates declined more with flecainide (−22%) and digoxin (−13%) than with sotalol (−5%; P<0.001). Flecainide (HR=2.1; P=0.02) and digoxin (HR=2.9; P=0.01) were also associated with a higher rate of conversion of fetal SVT to a normal rhythm over time. No serious drug-related adverse events were observed, but arrhythmia-related mortality was 5%. Conclusion— Flecainide and digoxin were superior to sotalol in converting SVT to a normal rhythm and in slowing both AF and SVT to better-tolerated ventricular rates and therefore might be considered first to treat significant fetal tachyarrhythmia.

Contribution of Inherited Heart Disease to Sudden Cardiac Death in Childhood

BACKGROUND. In children aged 1 to 18 years, the causes of sudden cardiac death may remain unresolved when autopsy results are negative. Because inherited cardiac diseases are likely, cardiologic and genetic investigations of relatives may still yield the diagnosis in these cases. Moreover, these investigations provide timely identification of relatives who are also at risk of sudden cardiac death. We aimed to establish the cause of sudden cardiac death in the children of whom the family was referred to our cardiogenetics department and the diagnostic yield of these investigations. METHODS AND RESULTS. We genetically counseled 25 consecutive, unrelated families after sudden cardiac death of a child (aged 1 to 18 years) who was disease-free during lifetime and in whose family there was no known inherited heart disease. We performed cardiac investigation (electrocardiography, exercise testing, and echocardiography) of first-degree and second-degree relatives and performed diagnosis-directed DNA analysis. Autopsy was performed in 20 case subjects. A diagnosis was identified in 14 of 25 families. In addition, we studied 10 children after aborted sudden cardiac death; in 6 of them, a diagnosis was made. Overall, in 17 of the 19 families in whom an inherited disease was diagnosed, a disease-causing mutation in either a first-degree relative or the index patient confirmed the diagnosis. CONCLUSIONS. Sudden cardiac death in children seems to be caused often by inherited cardiac diseases. Cardiac and genetic examination of relatives combined, if possible, with postmortem analysis after sudden cardiac death of a child has a high diagnostic yield (14 of 25), comparable to analysis in surviving victims of sudden cardiac death (6 of 10). Because sudden cardiac death can be prevented by timely treatment, these results warrant active family screening after unexplained sudden cardiac death of a child.

Congenital heart defects in spinal muscular atrophy type I : A clinical report of two siblings and a review of the literature

A newborn girl presented with asphyxia, joint contractures and diminished spontaneous movements. Echocardiography showed hypoplastic left heart. Spinal muscular atrophy type I (SMA I) was diagnosed by detecting a homozygous deletion in the survival motor neuron 1 gene (SMN1). In the first trimester of a subsequent pregnancy, SMA I, hypoplastic left heart, and contractures were identified again. Congenital heart defects (CHD) have now been reported in 20 patients with SMA I, including three previously reported siblings and our two siblings, leading us to hypothesize that SMA I/CHD represents a unique phenotype of SMA I rather than a coincidental association. The homozygous SMN1 deletion may play a role in the development of CHD when it occurs in the presence of mutations or polymorphisms in other genes important for cardiac development.

The diagnostic and therapeutic aspects of loss-of-function cardiac sodium channelopathies in children.

BACKGROUND Loss-of-function sodium channelopathies manifest as a spectrum of diseases including Brugada syndrome (BrS) and cardiac conduction disease. OBJECTIVE To analyze the diagnostic and therapeutic aspects of these disorders in children. METHODS Patients aged ≤ 16 years with genetically confirmed loss-of-function sodium channelopathies (SCN5A mutation), presenting with cardiac symptoms, positive family history, and/or abnormal electrocardiogram (ECG), were included. Abnormal ECG consisted of type 1 BrS ECG and/or prolonged conduction intervals (PR interval/QRS duration > 98th percentile for age). RESULTS Among the cohort (n = 33, age 6 ± 5 years, 58% male subjects, 30% probands), 14 (42%) patients were symptomatic, presenting with syncope (n = 5), palpitations (n = 1), supraventricular arrhythmias (n = 3), aborted cardiac arrest (n = 3), and sudden cardiac death (n = 2). Heart rate was 91 ± 26 beats/min, PR interval 168 ± 35 ms, QRS duration 112 ± 20 ms, and heart-rate corrected QT interval 409 ± 26 ms. Conduction intervals were prolonged in 28 (85%) patients; 6 of these patients also had spontaneous type 1 BrS ECG. Eight fever-associated events occurred in 6 patients; 2 of these were vaccination-related fever episodes. Treatment included aggressive antipyretics during fever in all patients; antiarrhythmic treatment included implantable cardioverter-defibrillator (n = 4), pacemaker (n = 2), and beta-blockers, either alone (n = 3) or in combination with device (n = 2). During follow-up (4 ± 4 years), 2 previously symptomatic patients had monomorphic ventricular tachycardia; there were no deaths. CONCLUSIONS Diagnosis of loss-of-function sodium channelopathies in children relies on cardiac symptoms, family history, and ECG. Fever and vaccination are potential arrhythmia triggers; conduction delay is the commonest finding on ECG. Beta-blockers have a role in preventing tachycardia-induced arrhythmias; implantable cardioverter-defibrillator should probably be reserved for severe cases.

Fever-Induced Life-Threatening Arrhythmias in Children Harboring an SCN5A Mutation

Cardiac channelopathies caused by SCN5A mutation are well tolerated by most patients. However, the dramatic presentation of a previously healthy 4-month-old girl with life-threatening arrhythmias and the subsequent findings in the child and her family provide evidence that loss-of-function sodium channel mutations can present very early in life. An SCN5A mutation was detected in the infant, her brother, and their father. Both the siblings manifested recurrent serious arrhythmias during febrile episodes, which followed immunization, as well as fever of nonspecific origin. Management consisted of prompt antipyretic measures, hospitalization with vigorous monitoring during immunization and febrile episodes, and prevention of tachycardia-induced conduction disturbance with β-blockers.

Audit of 10 years of referrals for fetal echocardiography

To evaluate trends over time, indications, diagnoses, noncardiac defects and outcome of fetuses referred for tertiary level echocardiography.

Persistent Fetal Sinus Bradycardia Associated with Maternal Anti-SSA/Ro and Anti-SSB/La Antibodies

Objective. To study the clinical course and outcome of fetal sinus bradycardia (SB) due to maternal antibody-induced sinus node dysfunction. Methods. We reviewed the maternal, prenatal, and postnatal findings of fetuses with SB associated with elevated maternal anti-SSA/Ro and anti-SSB/La antibodies. Results. Of the 6 cases diagnosed prenatally, 3 had isolated SB persisting after birth and had a good prognosis. Three fetuses with SB and severe myocardial involvement (congenital complete heart block and/or endocardial fibroelastosis) succumbed in utero in spite of treatment. Postmortem histopathology in 1 fetus showed inflammatory destruction of the sinus and atrioventricular nodes. SB was detected incidentally in a 7-year-old girl. She had intermittent heart block with progressive sinus arrest requiring permanent pacemaker. Conclusion. Fetal SB associated with maternal autoantibodies may persist in childhood, with a good prognosis in the absence of widespread cardiac involvement.

Rhizomelic chondrodysplasia punctata and cardiac pathology

Background Rhizomelic chondrodysplasia punctata (RCDP) is an autosomal recessive peroxisomal disorder characterised by rhizomelia, contractures, congenital cataracts, facial dysmorphia, severe psychomotor defects and growth retardation. Biochemically, the levels of plasmalogens (major constituents of cellular membranes) are low due to a genetic defect in their biosynthesis. Cardiac muscle contains high concentrations of plasmalogens. Recently cardiac dysfunction was found in a mouse model for RCDP with undetectable plasmalogen levels in all tissues including the heart. This suggests the importance of plasmalogens in normal cardiac development and function. Congenital heart disease (CHD), however, has not been recognised as a major characteristic of RCDP. Aims We aimed to determine the prevalence of CHD found in RCDP patients as well as to describe genetic, biochemical and cardiac correlations. Methods We included 23 patients with genetically proven RCDP. The genetic, biochemical and physical data were evaluated. Echocardiograms were reviewed. Results Cardiac data were available for 18 patients. 12 (52%) had CHD. All twelve had type 1 RCDP and 11 (92%) had the PEX 7:c.875T>A mutation, of whom seven were homozygous (58%). Plasmalogen levels were significantly lower in the patients with CHD. Cardiac lesions included: septal defects (80% atrial), patent ductus arteriosus, pulmonary artery hypoplasia, tetralogy of Fallot and mitral valve prolapse (mostly older patients). Conclusions The CHD prevalence among RCDP patients was at least 52%, significantly higher than among the normal population. Plasmalogen levels were significantly lower in patients with CHD. Routine cardiac evaluation should be included in the clinical management of RCDP patients.

Cardiac function in pediatric septic shock survivors.

OBJECTIVE To evaluate the long-term effects of septic shock on cardiac function in children treated with inotropic and/or vasoconstrictive agents for 24 hours or longer. DESIGN Cohort study. SETTING Tertiary pediatric intensive care unit and outpatient follow-up clinic. PARTICIPANTS One hundred eight of 144 eligible children who were admitted to our tertiary pediatric intensive care unit with septic shock from 1995 through 2005 and were alive in 2006 were invited to participate and visit our outpatient follow-up clinic. Fifty-two healthy controls were included. MAIN EXPOSURE Septic shock survival. OUTCOME MEASURES History, physical examination, electrocardiogram during rest and exercise, 24-hour electrocardiography registration, and left and right ventricular function. RESULTS No children had abnormalities when histories were taken or during physical examination that were attributable to cardiac dysfunction. Six children (6%) had cardiac abnormalities: polymorphic premature ventricular contractions during exercise and 24-hour electrocardiography registration (2 patients), decreased left ventricular function (2 patients), decreased left ventricular function and polymorphic premature ventricular contractions (1 patient), and decreased right ventricular function (1 patient). CONCLUSIONS In this small and diverse group of pediatric septic shock survivors, we found an excellent recovery of cardiac performance in most patients. In a limited number of patients, we found rhythm disturbances and decreased ventricular function. We believe that, against the background of aging, long-term cardiac follow-up of these patients is important.