Majid Al-Fayyadh

Outcomes of Damus-Kaye-Stansel anastomosis at time of cavopulmonary connection in single ventricle patients at risk of developing systemic ventricular outflow tract obstruction †

OBJECTIVES Children with various single ventricle anomalies are at risk of developing systemic ventricular outflow tract obstruction (SVOTO) following volume unloading with cavopulmonary connection (CPC). We aim to evaluate the value of Damus-Kaye-Stansel (DKS) anastomosis at the time of CPC in eliminating late SVOTO risk. METHODS Retrospective review of single ventricle patients who underwent DKS concurrent with CPC between 1997 and 2012 was performed. Clinical, echocardiographic and angiographic outcomes were analysed. RESULTS Thirty-six children with single ventricle underwent DKS at the time of Glenn bidirectional CPC (n = 29) or Fontan total CPC (n = 7). The underlying anatomy was double inlet left ventricle (n = 18), double outlet right ventricle (n = 8), unbalanced atrioventricular septal defect (n = 4) and other (n = 6). Prior palliation included pulmonary artery band (n = 35), coarctation/arch repair (n = 11) and atrial septectomy (n = 8). Median age at the time of DKS was 8.9 months (range 3.6 months-9.1 years) and the median weight was 6.7 kg (range 5-27 kg). At the time of DKS, 17 patients (47%) had no SVOT gradient and 19 (53%) had SVOT gradient (mean 23.4 ± 18.7 mmHg). Overall survival was 89 and 83% at 1 month and 5 years, respectively. None of the deaths were related to SVOTO or DKS complications. When present, SVOT gradient decreased from 23.4 ± 18.7 mmHg preoperatively to 0 after DKS (P < 0.001). At the last follow-up, none of the patients developed any SVOT gradient; 78% of them had zero or trivial aortic/neoaortic valve regurgitation while 22% had mild regurgitation. None of the patients had evidence of compression of the left pulmonary artery or bronchus. Eighty-one percent of patients have reached or are suitable candidates awaiting final palliative surgery. CONCLUSIONS DKS can be safely performed in conjunction with CPC without added mortality risk. It is very effective in mitigating SVOTO risk, with sustainable good semilunar valves function. Our data support an aggressive approach to performing DKS concurrent with CPC in children with single ventricle pathologies at risk of developing SVOTO.

Recessively Inherited Severe Aortic Aneurysm Caused by Mutated EFEMP2

Familial aortic aneurysm (AA) is mostly inherited as an autosomal dominant disorder. However, recessively inherited AA has also been observed but in association with skin manifestations of cutis laxa, which is caused by a mutated EFEMP2 gene. In the present study, we recruited 9 patients, from 4 unrelated consanguineous families, with recessively inherited AA. The index cases, their parents, and siblings underwent clinical evaluation and cardiac imaging. In the affected subjects, the clinical presentation ranged from sweating and cyanosis at 3 months of age to incidental findings in an asymptomatic adult. The echocardiogram revealed a wide spectrum of severity of the AA, with a Z-score varying from 5 to 33. Intrafamilial variability was also evident; 2 unrelated subjects were detected at 17 and 20 years of age through family screening. The skin manifestations of cutis laxa were not found in any patient. In 1 family, genome-wide single-nucleotide polymorphism analysis detected a homozygous block, shared by 2 affected siblings, on chromosome 11 at q13. Sequence analysis of EFEMP2, located on chromosome 11 at q13, identified a novel homozygous mutation (p.E161K) in all 9 affected subjects. In this largest cohort of reported patients with a mutated EFEMP2 gene, we illustrate the phenotypic spectrum of inherited AA due to a novel EFEMP2 mutation. In conclusion, our work suggests that in families with apparently recessively inherited AA, molecular analysis of EFEMP2 gene might be warranted.

Potential New Indication for Ivabradine: Treatment of a Patient with Congenital Junctional Ectopic Tachycardia

Ivabradine is a new antiarrhythmic agent with direct inhibition of the pacemaker (If) current. It has been used extensively to decrease sinus rate in the treatment of cardiac failure, and also in a single case of atrial ectopic tachycardia in a child. Here we report the case of a 3‐year‐old girl with congenital junctional ectopic tachycardia (JET), resistant to conventional antiarrhythmic medications, who was successfully treated with ivabradine. We suggest that ivabradine can be an effective treatment for junctional automatic tachycardias and can be considered as a new line of therapy for this incessant form of tachycardia.

The Phenotype and Outcome of Infantile Cardiomyopathy Caused by a Homozygous ELAC2 Mutation

Objective: Cardiomyopathy (CMP) in children is a clinically and genetically heterogeneous group of disorders. Disease-associated mutations have been identified in more than 50 genes. Recently, mutations in the mitochondrial tRNA processing gene, ELAC2, were reported to be associated with the recessively inherited form of hypertrophic CMP (HCM). This study is aimed at describing the cardiac phenotype and outcome of ELAC2 mutation. Methods: We performed whole exome sequencing followed by targeted mutation screening to identify the genetic etiology of severe infantile-onset CMP in 64 consanguineous Saudi families. Results: A previously reported mutation (p.Phe154Leu) in ELAC2 gene was detected in 16 families. The index cases presented between 2 and 7 months of age with HCM in 13 infants and dilated CMP (DCM) in 3. Pericardial effusion was observed in 7 infants (44%). All infants died with a median age of death of 4 months. Almost 1/3 of them died during the initial presentation. Conclusion: Our study suggests screening the ELAC2 gene in severe infantile-onset HCM or DCM of unknown etiology, especially in the presence of pericardial effusion. Our work demonstrates a universally poor outcome of the (p.Phe154Leu) variant in ELAC2 gene; a correlation that helps in counseling parents and in planning appropriate medical intervention.

The Phenotype of a CASQ2 Mutation in a Saudi Family with Catecholaminergic Polymorphic Ventricular Tachycardia

Catecholaminergic polymorphic ventricular tachycardia (CPVT) manifests with episodic syncope or sudden death in young patients following physical activity or emotional stress. The autosomal recessive form of CPVT is caused by mutations in the CASQ2 gene. In a consanguineous family, a novel homozygous CASQ2 mutation (p.L77P) was identified in a child with CPVT who required implantation of a cardioverter defibrillator due to episodes of syncope while on medical therapy. Genetic testing found the younger sibling, who had normal initial clinical screening, to be affected. Our cases underscore the importance of family screening through genetic testing to preemptively apply the appropriate medical intervention in CPVT. (PACE 2013; 36:e140–e142)

Hyperinsulinism in a child presenting with cardiac ischemia and bradycardia.

A 5-year-old boy referred to our service with suspected sinus node dysfunction. In addition to the arrhythmia, he had moderate mitral valve regurgitation and depressed ventricular function during a hypoglycemic episode. Cardiac abnormalities resolved with glucose infusion. We believe that hypoglycemia was responsible for the cardiac manifestations and it should be considered in unexplained rhythm disturbances or ischemia.