A case of an infant with compound heterozygous mutations for hypertrophic cardiomyopathy producing a phenotype of left ventricular noncompaction.

A male infant was born to a 38-year-old G1P0 mother with hypertrophic cardiomyopathy (HCM). Fetal echocardiography was suspicious for HCM; however, postnatal echocardiography demonstrated features consistent with left ventricular noncompaction (LVNC). The infant was initially stable but presented at 2 months of age in cardiogenic shock. On genetic analysis, both parents were heterozygous for mutations associated with HCM. The proband was a compound heterozygote. This case, in which 2 mutations for HCM produced a phenotype of LVNC, has not been demonstrated in humans and raises the question of whether HCM and LVNC represent a continuum of pathologic processes.

Serum troponin-I as an indicator of clinically significant myocardial injury in paediatric trauma patients.

Myocardial injury is a cause of mortality in paediatric trauma, but it is often difficult to diagnose. The objectives of this pilot study were to (1) determine the prevalence of elevated cardiac troponin I (TnI) in paediatric trauma patients and (2) to determine whether elevated TnI correlates with clinically significant myocardial injury, defined as abnormalities on echocardiogram (ECHO) and/or electrocardiograms (ECG). To this end, we investigated a convenient sample size of 59 paediatric trauma patients with an Injury Severity Score (ISS)>12. TnI and creatine kinase-MB (CK-MB) were measured on admission, at then at regular intervals until TnI had normalized. Patients with elevated TnI levels had an ECHO performed within 24h of admission and underwent daily ECGs until TnI normalized. Elevated serum TnI was found in n=16/59 (27%; 95% CI: 18-40%) patients and was associated with elevated CK-MB in all cases. Abnormal ECHOs were seen in 4/16 patients with elevated TnI, but peak TnI values did not correlate with abnormalities on ECHO (p=0.23). Only 1 patient had a clinically significant, albeit mild, decrease in cardiac function. All ECGs were normal. Patients with elevated TnI were more likely to be intubated (p=0.04), to have higher Injury Severity Scores (p=0.02), required more resuscitation fluid (p=0.001), and to have thoracic injuries (p<0.001). Our data indicates that the prevalence of elevated TnI in paediatric trauma patients is 27%; and whilst elevated TnI reflects overall trauma severity, it is frequently elevated without a clinically significance myocardial injury. Hence, large scale studies are required to determine if an elevated threshold TnI value can be identified to accurately diagnose severe myocardial injury in paediatric trauma.

Accelerated ventricular rhythm in healthy neonates.

Accelerated ventricular rhythm is similar in rate to the original sinus rhythm. Although 19 cases have been reported in healthy neonates without congenital disease, it is seen with some regularity at tertiary care paediatric cardiac centres. Accelerated ventricular rhythm carries good prognosis, but it is frequently misdiagnosed as ventricular tachycardia and is, thus, unnecessarily treated. The present report describes a case of a neonate who was not properly diagnosed after birth and who was inappropriately treated.

Usability assessment of pacemaker programmers.

There is a perception among clinicians of usability differences in the user interface of pacemaker programmers, but there is an absence of literature in this area. The purpose of this study was to describe usability differences in pacemaker programmers. Forty-two programmer users completed self-administered questionnaires and two usability experts independently performed heuristic evaluation to identify features that violated general usability principles. Programmers from seven manufacturers (coded A-G) were evaluated. There was a balanced representation of users: nurses (58%) versus technologists (40%) who are employed in community (50%) versus academic (45%) hospitals, novice versus expert users based on the median users' programming experience of 60 months (range 1-300 months). Significant differences between programmers were found in overall user satisfaction and ease of programmer use (P < 0.0001) in the display, controls, operation, and physical dimension of the programmers (P < 0.05). Heuristic evaluations showed frequent violations of usability principles in all programmers. Problematic areas include reliance on user recall, inconsistency in operation of critical controls, poor readability, and not anticipating user wants or action. Programmer interface designs do not consistently meet user needs or general usability principles. This impacts on the safe and effective use of programmers. Guidelines in programmer design should be established, particularly with respect to labeling, location, and operation of critical controls.

Síndrome nefrítico en pediatría / Nephritic syndrome in pediatrics

El síndrome nefrítico (SN) es uno de los más frecuentes en nefrología. Se conforma por la presencia de hipertensión arterial, edema, hematuria, oliguria y retención de azoados. Se realiza una revisión de la literatura enfocada a la principal causa pediátrica de este síndrome: la glomerulonefritis postestreptocócica. Se analiza su fisiopatología, la correlación clínica y, finalmente, se propone una ruta crítica para el diagnóstico y manejo de la hipertensión arterial en esta patología.