Instability of repolarization in LQTS mutation carriers compared to healthy control subjects assessed by vectorcardiography
| Autor: | Gabriel Bergqvist, Ulla-Britt Diamant, Farzad Vahedi, Gunilla Lundahl, Lennart Bergfeldt, Lennart Gransberg, Steen M. Jensen |
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| Rok vydání: | 2013 |
| Předmět: |
Adult
Male congenital hereditary and neonatal diseases and abnormalities medicine.medical_specialty Long QT syndrome Vectorcardiography Electrocardiography QRS complex Heart Rate Physiology (medical) Internal medicine Heart rate medicine Humans Repolarization medicine.diagnostic_test business.industry Middle Aged medicine.disease Potassium channel Long QT Syndrome Mutation Mutation (genetic algorithm) cardiovascular system Cardiology Female Cardiology and Cardiovascular Medicine business |
| Zdroj: | Heart Rhythm. 10:1169-1175 |
| ISSN: | 1547-5271 |
| DOI: | 10.1016/j.hrthm.2013.05.001 |
| Popis: | Potassium channel dysfunction in congenital and acquired forms of long QT syndrome types 1 and 2 (LQT1 and LQT2) increases the beat-to-beat variability of the QT interval.To study about the little known variability (instability) of other aspects of ventricular repolarization (VR) in humans by using vectorcardiography.Beat-to-beat analysis was performed regarding vectorcardiography derived RR, QRS, and QT intervals, as well as T vector- and T vector loop-based parameters during 1-minute recordings of uninterrupted sinus rhythm at rest in 41 adult LQT1 (n = 31) and LQT2 (n = 10) mutation carriers and 41 age- and sex-matched control subjects. The short-term variability for each parameter, describing the mean orthogonal distance to the line of identity on the Poincaré plot, was calculated.Mutation carriers showed significantly larger (by a factor 2) instability in most VR parameters compared to controls despite higher instantaneous heart rate variability (STVRR) in the control group. The longer the QT interval, the greater was its instability, and the instability of VR dispersion measures.A greater instability of most aspects of VR already at rest seems to be a salient feature in both LQT1 and LQT2, which might pave the way for early afterdepolarizations and torsades de pointes ventricular tachycardia. In contrast, no signs of increased VR dispersion per se were observed in mutation carriers. |
| Databáze: | OpenAIRE |
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