Repolarization morphology in adult LQT2 carriers with borderline prolonged QTc interval
| Autor: | Jean-Philippe Couderc, Wojciech Zareba, Arthur J. Moss, Scott McNitt, Jean Xia |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
Adult
Male QTC PROLONGATION ERG1 Potassium Channel congenital hereditary and neonatal diseases and abnormalities medicine.medical_specialty Time Factors Long QT syndrome RR interval Population Action Potentials Logistic regression Sensitivity and Specificity QT interval Electrocardiography Heart Conduction System Heart Rate Predictive Value of Tests Physiology (medical) Internal medicine medicine Humans Repolarization cardiovascular diseases education education.field_of_study business.industry Models Cardiovascular Prolonged QTc interval medicine.disease Ether-A-Go-Go Potassium Channels Long QT Syndrome Logistic Models Phenotype ROC Curve Research Design Anesthesia Mutation Cardiology Female Cardiology and Cardiovascular Medicine business |
| Zdroj: | Heart Rhythm. 3:1460-1466 |
| ISSN: | 1547-5271 |
| DOI: | 10.1016/j.hrthm.2006.08.009 |
| Popis: | Background At least 50% of LQT2 carriers have borderline QTc (0.42–0.47 s), and they present a diagnostic difficulty to clinicians evaluating patients suspected of having long QT syndrome (LQTS). Objectives Because QTc in this borderline range is nondiagnostic, the purpose of this study was to investigate whether analysis of phenotypic features of T-wave morphology could help identify LQT2 carriers with normal or near-normal QTc-interval duration. Methods Standard 12-lead ECGs recorded without beta-blockers from LQT2 carriers (n = 90, 33 ± 14 years, 61% female) and noncarriers (n = 69, 38 ± 17 years, 58% female) were digitized. The following parameters were automatically measured: RR interval, QT/QTc, QT apex, T-wave amplitude, ascending (α L ) and descending slopes (α R ) of the T wave, and T-wave symmetry. We used a linear logistic regression model to identify the most relevant parameters for separating LQT2 carriers from noncarriers, within the overall population and among patients without overt QTc prolongation (390 ≤ QTc ≤ 470). Results Logistic regression selected three parameters: QT, RR interval, and α L in all models. In the overall population, the model provided 92.7% sensitivity and 90.0% specificity. In the group of patients without beta-blockers and near-normal QTc interval, 92.0% sensitivity (n = 46) and 81.4% specificity (n = 49) were achieved by the model including α L. Conclusion Abnormal T-wave morphology is a phenotypic expression of LQT2, and its quantification could be used to identify patients with suspected LQTS who do not have overt QTc prolongation (QTc >470). |
| Databáze: | OpenAIRE |
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