T Wave Amplitude Correction of QT Interval Variability for Improved Repolarization Lability Measurement

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Personen und Körperschaften:	Schmidt, Martin, Baumert, Mathias, Malberg, Hagen, Zaunseder, Sebastian
Titel:	T Wave Amplitude Correction of QT Interval Variability for Improved Repolarization Lability Measurement
Format:	E-Artikel
Sprache:	Englisch
veröffentlicht:	Lausanne Frontiers Research Foundation Online-Ausg.. 2017
Gesamtaufnahme:	, Frontiers in Physiology (April 2016), 7, ISSN: 1664-042X. DOI: 10.3389/fphys.2016.00216. Artikelnr.: 216
Schlagwörter:	Ekg Qt-Intervallvariabilität T-Wellenamplitude Risikostratifizierung Definite Tu Dresden Publikationsfond Ecg Qt Interval Variability T Wave Amplitude Risk Stratification Publishing Fund
Quelle:	Qucosa

Details
Zusammenfassung:	Objectives: The inverse relationship between QT interval variability (QTV) and T wave amplitude potentially confounds QT variability assessment. We quantified the influence of the T wave amplitude on QTV in a comprehensive dataset and devised a correction formula. Methods: Three ECG datasets of healthy subjects were analyzed to model the relationship between T wave amplitude and QTV. To derive a generally valid correction formula, linear regression analysis was used. The proposed correction formula was applied to patients enrolled in the Evaluation of Defibrillator in Non-Ischemic Cardiomyopathy Treatment Evaluation trial (DEFINITE) to assess the prognostic significance of QTV for all-cause mortality in patients with non-ischemic dilated cardiomyopathy. Results: A strong inverse relationship between T wave amplitude and QTV was demonstrated, both in healthy subjects (R2 = 0.68, p < 0.001) and DEFINITE patients (R2 = 0.20, p < 0.001). Applying the T wave amplitude correction to QTV achieved 2.5-times better group discrimination between patients enrolled in the DEFINITE study and healthy subjects. Kaplan-Meier estimator analysis showed that T wave amplitude corrected QTVi is inversely related to survival (p < 0.01) and a significant predictor of all-cause mortality. Conclusion: We have proposed a simple correction formula for improved QTV assessment. Using this correction, predictive value of QTV for all-cause mortality in patients with non-ischemic cardiomyopathy has been demonstrated.