RESUMO
AIMS: Sudden cardiac death (SCD) is challenging to predict. Electrocardiogram (ECG)-derived heart rate-corrected QT-interval (QTc) is used for SCD-risk assessment. QTc is preferably determined manually, but vendor-provided automatic results from ECG recorders are convenient. Agreement between manual and automatic assessments is unclear for populations with aberrant QTc. We aimed to systematically assess pairwise agreement of automatic and manual QT-intervals and QTc. METHODS AND RESULTS: A multi-centre cohort enriching aberrant QTc comprised ECGs of healthy controls and long-QT syndrome (LQTS) patients. Manual QT-intervals and QTc were determined by the tangent and threshold methods and compared to automatically generated, vendor-provided values. We assessed agreement globally by intra-class correlation coefficients and pairwise by Bland-Altman analyses and 95% limits of agreement (LoA). Further, manual results were compared to a novel automatic QT-interval algorithm. ECGs of 1263 participants (720 LQTS patients; 543 controls) were available [median age 34 (inter-quartile range 35) years, 55% women]. Comparing cohort means, automatic and manual QT-intervals and QTc were similar. However, pairwise Bland-Altman-based agreement was highly discrepant. For QT-interval, LoAs spanned 95 (tangent) and 92â ms (threshold), respectively. For QTc, the spread was 108 and 105â ms, respectively. LQTS patients exhibited more pronounced differences. For automatic QTc results from 440-540â ms (tangent) and 430-530â ms (threshold), misassessment risk was highest. Novel automatic QT-interval algorithms may narrow this range. CONCLUSION: Pairwise vendor-provided automatic and manual QT-interval and QTc results can be highly discrepant. Novel automatic algorithms may improve agreement. Within the above ranges, automatic QT-interval and QTc results require manual confirmation, particularly if T-wave morphology is challenging.
Assuntos
Eletrocardiografia , Síndrome do QT Longo , Humanos , Feminino , Adulto , Masculino , Síndrome do QT Longo/diagnóstico , Morte Súbita Cardíaca/etiologia , Morte Súbita Cardíaca/prevenção & controle , Arritmias Cardíacas , Medição de RiscoAssuntos
Anomalia de Ebstein/diagnóstico por imagem , Ecocardiografia Quadridimensional/métodos , Imagem Cinética por Ressonância Magnética/métodos , Insuficiência da Valva Tricúspide/diagnóstico por imagem , Anomalia de Ebstein/complicações , Anomalia de Ebstein/fisiopatologia , Humanos , Monitorização Fisiológica/métodos , Sensibilidade e Especificidade , Insuficiência da Valva Tricúspide/complicações , Insuficiência da Valva Tricúspide/fisiopatologiaRESUMO
Age- and gender-related differences in QTc-interval are most likely the result of changes in sex-specific hormones. Although the exact mechanisms and pathophysiology of sex hormones on the QTc-interval are not known, testosterone appears to shorten the QTc-interval. In females, however, there is a more complex interaction between progesterone and estrogen. In patients with an impaired repolarization, such as long-QT syndrome (LQTS), the effect of these sex hormones on the QTc-interval is more pronounced with a differing sensitivity between the LQTS genotypes.