Clinical characteristics of neonates with inborn errors of metabolism detected by Tandem MS analysis in Oman.

We reviewed the clinical profile of our neonates diagnosed to have inborn errors of metabolism (IEM) by Tandem Mass Spectrometry (TMS) over a seven years period, and compared the results with published reports. We also attempted to evaluate various clinical situations wherein the screening test would yield a high pick up rate. Among the 166 neonates studied (10 aged 1 day, 79 aged 2-7 days and 77 aged 8-28 days), significant abnormalities on TMS suggestive of IEM were detected in 38 babies (23%), most common diseases diagnosed were maple syrup urine disease (10 neonates), propionic acidemia (8 neonates), urea cycle diseases (6 neonates) and isovaleric acidemia (4 neonates). The detection incidence was calculated to be one positive case out of every 4 to 5 babies tested. A high prevalence of parental consanguinity and high level of positive family history of affected siblings were the highlights of this study. The major clinical situations where testing was helpful were (a) unexplained acute neonatal encephalopathy, (b) positive family history of known or suspected IEM and (c) new born presenting with abnormal serum biochemistry suggestive of IEM.

Right atrial rhabdomyoma acting as the substrate for Wolff-Parkinson-White syndrome in a 3-month-old infant.

We report a 3-month-old infant girl who presented with supraventricular tachycardia, who was detected to have a large right atrial rhabdomyoma and evidence of Wolff-Parkinson-White (WPW) syndrome with an accessory pathway corresponding to the position of the tumour. In view of the resistant cardiac arrhythmia and large size of the tumour, the infant underwent surgical excision of the tumour. The evidence of WPW syndrome disappeared from the surface electrocardiogram immediately upon removal of the tumour. A second resolving tumour in the interventricular septum was also detected during the investigation. Although there are no other stigmata of tuberous sclerosis at present, our infant requires close follow-up. Right atrial rhabdomyomas are rare and to our knowledge this is the first reported instance where we could document clearly that the tumour itself formed the substrate for the WPW syndrome.

Survival analysis of patients with idiopathic dilated cardiomyopathy in Oman.

OBJECTIVE: To study the 10-year survival of adults with idiopathic dilated cardiomyopathy (IDC) in Oman. METHODS: Ninety-seven patients aged >13 years with IDC attending the Cardiology Unit, Sultan Qaboos University Hospital, Muscat, Oman from 1992-1995 were prospectively studied, in order to identify the outcome and factors contributing to death. RESULTS: Among 97 patients, 2 died from acute heart failure at presentation. The remaining 95 patients were followed up for periods ranging from 1-10 years (median 7 years). Twenty-four out of 95 patients exhibited clinical deterioration with reduced left ventricular ejection fraction (LVEF), by 5-11%, and 17 of them expired due to resistant heart failure. The remaining 71 patients remained stable and did not show deterioration in LVEF; however, 7 of them died suddenly at home possibly from ventricular arrhythmia. The survival rates were 94% at one year (95% confidence interval [CI] 88% to 99%), 86% at 3 years (95% CI 79% to 93%), and 64% at 10 years (95% CI 51% to 78%). Mean survival was 6.5 years (95% CI 6 to 7 years). Multivariate regression analysis revealed that factors related to death were LVEF <30% (p<0.001) and presence of severe mitral regurgitation (p=0.01). CONCLUSION: Outcome of dilated cardiomyopathy has improved due to greater understanding of this condition leading to better therapeutic approach. Resistant heart failure and cardiac arrhythmias remain the main causes of mortality. Poor outcome was related to low LVEF and presence of severe mitral regurgitation.

Accidental detection of a giant right atrial aneurysm in an asymptomatic infant.

We present a 4-month old infant boy accidentally detected to have cardiomegaly on a chest radiograph, and on further investigation discovered to have a giant right atrial aneurysm and a secundum atrial septal defect. Congenital right atrial aneurysm or diverticulum is a rare anomaly, usually presenting with atrial or supraventricular tachycardia. Previously reported patients did not have any associated congenital heart defect. Although asymptomatic our patient needs close follow-up, and surgical resettion of the aneurysm and closure of the atrial septal defect in view of potential complications.

Antiphospholipid syndrome presenting as dilated cardiomyopathy in an 11-year-old boy.

We report on an 11-year-old Omani boy who presented with acute heart failure due to dilated cardiomyopathy. Examination revealed the presence of left ventricular thrombi on echocardiography and a marked elevation of anticardiolipin antibodies. Subsequently the boy exhibited features of antiphospholipid syndrome including multiple thrombotic episodes involving the brain, and renal and iliac veins. We could not document any underlying cause of the antiphospholipid syndrome. His cardiac status subsequently deteriorated and he expired from multiorgan failure. Resistant heart failure from dilated cardiomyopathy secondary to primary antiphospholipid syndrome is uncommon and has not been reported in children.

Malignant familial long QT syndrome.

We report a family with congenital long QT syndrome, an inherited disorder of myocardial repolarization in which affected individuals have prolongation of corrected QT interval on the electrocardiogram and a tendency to develop ventricular arrhythmia, leading to syncope, convulsion or sudden death. Our family is characterized by several affected members (11/16), early onset of symptoms, malignant course prior to diagnosis and good response to beta-blocker therapy. The genetic basis of long QT syndrome has been traced to defective proteins encoding cardiac ion channels. Diagnosis is based on an unexplained prolongation of QT interval >0.45 second in the presence of suggestive symptoms or evidence, or both of a familial pattern. Beta-adrenergic blocker therapy gives symptomatic relief in 80%-85% of patients. Precipitating factors like vigorous exercise especially swimming and exposure to significant emotional or auditory stimuli should be avoided. Occasional patients require in addition, a demand cardiac pacemaker, left cardiac sympathectomy or an implantable cardioverter-defibrillator, or both. Regular follow up is mandatory even after subsidence of symptoms.

Dizziness during pregnancy due to cardiac myxoma.

A woman in the second trimester of pregnancy with recurrent episodes of dizziness is presented. She had a large left atrial myxoma that interfered with left ventricular filling, compromising cardiac output accounting for the symptoms. Surgical excision of the tumor was performed successfully during pregnancy.

An unusual presentation of metabolic cardiomyopathy due to Pompe's disease.

An Omani infant boy who presented in the neonatal period with cardiac failure secondary to hypertrophic cardiomyopathy is reported. He subsequently progressed to show features of a metabolic disorder with multisystem involvement and was diagnosed to have Type II glycogenosis (Pompe's disease). The differential diagnosis and management of metabolic cardiomyopathy are outlined.

Accidental tricyclic antidepressant poisoning in a 2 year-old boy.

We present a 2-year old boy with accidental ingestion of a tricyclic antidepressant and outline the clinical features, management and prevention. Despite ingesting a high dose of amitriptyline (20mg/kg) and showing serum levels above the toxic range (1380 ng/ml), our patient did not develop any life threatening complications. Gastric lavage followed by instillation of activated charcoal, repeated at 6 hours, along with supportive measures led to complete recovery in 48 hours. As children are often exposed to tricyclic antidepressant poisoning, their carers and physicians need to be well aware of the disorder and its management.

Myclonic seizures in a young girl with Fishers variant of Guillain-Barre syndrome.

A 10-year-old girl with Fischer`s variant of acute Guillain-Barre syndrome is described. She had predominantly sensory involvement with autonomic dysfunction, ophthalmoplegia and myoclonic jerks. Myoclonus persisted for 2 weeks and the pupillary involvement was evident even after 2 months. The association of myoclonus with Guillain-Barre syndrome has not been previously reported.

Weak Radial Artery Pulse: An unusual congenital cause.

We present an 11year-old boy with a weak right radial pulse, and describe the successful application of vascular ultrasound to identify the ulnar artery dominance and a thin right radial artery with below normal Doppler flow velocity that could explain the discrepancy. The implications of identifying this anomaly are discussed.

IgA nephropathy presenting clinical features of poststreptococcal glomerulonephritis.

IgA nephropathy and poststreptococcal glomerulonephritis are common forms of primary glomerulonephritis in children. This paper reports a 5-year-old Omani boy who had a chance occurrence of these two different glomerular diseases. Our patient presented with clinical features of poststreptococcal glomerulonephritis and then developed recurrent macroscopic hematuria, polyarthritis, bloody diarrhea, and erythematous swelling of the penis. Renal biopsy revealed diffuse mesangial hypercellularity, with focal glomerular sclerosis, fibrous crescents, and mesangial IgA and C3 deposits, consistent with IgA nephropathy. The clinical features and differential diagnosis are outlined.