Exercise and arrhythmic risk in TMEM43 p.S358L arrhythmogenic right ventricular cardiomyopathy.

BACKGROUND: High-level exercise has been associated with a malignant phenotype in desmosomal and genotype-negative forms of arrhythmogenic right ventricular cardiomyopathy (ARVC). This is the first study to examine this issue with ARVC secondary to the TMEM43 p.S358L mutation. OBJECTIVE: The purpose of this study was to evaluate the impact of exercise on arrhythmic risk and cardiac death in TMEM43 p.S358L ARVC. METHODS: Individuals with the TMEM43 p.S358L mutation enrolled in a prospective registry who had received a primary prevention implantable cardioverter-defibrillator (ICD) were invited to complete the modified Paffenbarger Physical Activity Questionnaire to assess their physical activity in the year before their ICD implantation. Time-to-event analyses using unadjusted and adjusted Cox proportional hazards models evaluated associations between physical activity and first appropriate ICD discharge secondary to malignant ventricular arrhythmia or cardiac death. RESULTS: In 80 subjects with the TMEM43 p.S358L mutation, exercise ≥9.0 metabolic equivalent of task (MET)-hours/day (high level) in the year before ICD implantation was associated with an adjusted 9.1-fold increased hazard of first appropriate ICD discharge (there were no deaths) relative to physical activity <9.0 MET-hours/day (moderate level) (95% confidence interval [CI] 3.3-24.6 MET-hours/day; P < .001). The median age from birth to first appropriate ICD discharge was 58.5 years (95% CI 56.5-60.5 years) vs 35.8 years (95% CI 28.2-43.4 years) (P < .001) in subjects in moderate- and high-level exercise groups, respectively. CONCLUSION: Exercise ≥9.0 MET-hours/day is associated with an increased risk of malignant ventricular arrhythmias in the TMEM43 p.S358L subtype of ARVC. Extrapolating these data, we suggest molecular testing be offered in early childhood to inform exercise choices reflective of the genotype.

Electrocardiogram interpretation by Canadian general paediatricians: Examining practice, accuracy and confidence.

BACKGROUND: Paediatric electrocardiograms (ECGs) are ordered and interpreted by general paediatricians; however, no previous studies have evaluated the accuracy of their ECG interpretations. OBJECTIVE: To determine general paediatricians' practice and opinions regarding ECG use, accuracy of their interpretation of paediatric ECGs, and the relationship between accuracy and self-perceived confidence. METHODS: In the present cross-sectional study, Canadian general paediatricians were asked to complete a questionnaire and interpret 18 paediatric ECGs. The questionnaire assessed characteristics of ECG use, self-perceived confidence and opinions regarding ECG use in general paediatric practice. For the ECGs provided, respondents were asked whether the ECG was normal or abnormal, what abnormality the ECG demonstrated and how confident they were in this interpretation. RESULTS: ECG interpretation was performed by 124 general paediatricians. General paediatricians frequently use ECGs in their practice and regard this investigation as useful in patient assessment. The mean (± SD) accuracy of identifying ECGs as normal or abnormal, and identifying the specific abnormality was 80±12% and 56±20%, respectively. The sensitivity and specificity of identifying abnormal ECGs were 80% (95% CI 78% to 82%) and 79% (95% CI 75% to 83%), respectively. Correct ECG interpretation for isolated rhythm disturbances (73%) was significantly better than for abnormalities in axis (25%), chamber hypertrophy (41%) and ECG intervals (49%) (P<0.001). Overall confidence in ECG interpretation correlated with and was the only significant predictor of interpretation accuracy (r=0.396, P<0.001). CONCLUSION: General paediatricians were adept at detecting abnormal ECGs, but were less able to identify the abnormalities. Further education in ECG interpretation may be important for this population.

HISTORIQUE: Ce sont des pédiatres généralistes qui demandent et interprètent les électrocardiogrammes (ECG) en pédiatrie, mais aucune étude n'a porté sur l'exactitude de leur interprétation. OBJECTIF: Déterminer la pratique et les avis des pédiatres généralistes en matière d'utilisation des ECG et de l'exactitude des ECG en pédiatrie et établir le lien entre la précision et l'autoperception de la confiance. MÉTHODOLOGIE: Dans la présente étude transversale, les pédiatres généralistes canadiens ont été invités à remplir un questionnaire et à interpréter 18 ECG en pédiatrie. Le questionnaire visait à évaluer les caractéristiques liées à l'utilisation des ECG, l'autoperception de la confiance et les avis relatifs à l'utilisation des ECG en pédiatrie générale. Les répondants étaient invités à préciser si les ECG four-nis étaient normaux ou anormaux, les anomalies démontrées et leur confiance quant à leur interprétation. RÉSULTATS: Cent vingt-quatre pédiatres généralistes ont interprété les ECG. Les pédiatres généralistes utilisent souvent les ECG dans leur pratique et les considèrent comme utiles dans l'évaluation des patients. L'exactitude moyenne dans l'identification des ECG comme normaux ou anormaux et dans la détermination de l'anomalie précise correspondait à 80±12 % et à 56±20 %, respectivement. La sensibilité et la spécificité de l'identification des ECG anormaux s'établissaient à 80 % (95 % IC 78 % à 82 %) et à 79 % (95 % IC 75 % à 83 %), respectivement. La bonne interprétation des ECG révélant des troubles isolés du rythme cardiaque (73 %) était considérablement plus élevée que celle des anomalies de l'axe (25 %), de l'hypertrophie ventriculaire (41 %) et des intervalles d'ECG (49 %) (P<0,001). Dans l'ensemble, la confiance à l'égard de l'interprétation des ECG était corrélée avec l'exactitude des interprétations et en était le seul prédicteur important (r=0,396, P<0,001). CONCLUSION: Les pédiatres généralistes décelaient bien les ECG anormaux, mais réussissaient moins bien à déterminer les anomalies exactes. Il serait peut-être important de leur fournir un perfectionnement dans l'interprétation des ECG.

Commotio cordis and ventricular pseudoaneurysm.

A case of an eight-year-old boy who experienced commotio cordis with the development of myocardial infarction and a ventricular pseudoaneurysm is described. Progressive enlargement of the aneurysm resulted in distortion and compression of the overlying coronary arteries, causing myocardial ischemia.