Title
|
|
|
|
Individualized corrected QT interval is superior to QT interval corrected using the Bazett formula in predicting mutation carriage in families with long QT syndrome
| |
Author
|
|
|
|
| |
Abstract
|
|
|
|
BACKGROUND: Long QT syndrome (LQTS) is characterized by reduced penetrance and variable QT prolongation over time, resulting in an estimate of 25% carriers of a pathogenic mutation with a normal corrected QT (QTc) interval on the resting electrocardiogram (ECG). OBJECTIVE: The purpose of this study was to test the hypothesis that an individualized corrected QT interval derived from 24-hour Holter data more accurately predicts carriage of a pathogenic LQTS mutation than did QT derived from a standard 12-lead ECG and corrected using the Bazett formula (QTc interval). METHODS: Carriers of a pathogenic LQTS mutation and their genotype-negative family members who had both resting ECG and Holter recordings available were included. Automated and manual measurements of QTc were performed. QTi was derived from 24-hour Holter recordings and defined as the QT value at the intersection of an RR interval of 1000 ms, with the linear regression line fitted through QT-RR data points of each individual patient. RESULTS: In total, 69 patients with LQTS (23 long QT type 1, 39 long QT type 2, and 7 long QT type 3) and 55 controls were selected. Demographic characteristics were comparable. A comparison of the receiver operating characteristic curves indicates that the test added diagnostic value compared to manual measurement (P = .02) or automated measurement (P = .005). The diagnostic accuracy of manually measured QTc using conventional cutoff criteria was 72%, while it was 92% using a sex-independent QTi cutoff of 445 ms. This was caused by a 39% increase in sensitivity without compromising the specificity. CONCLUSION: QTi derived from Holter recordings is superior to conventional QTc measured from a standard 12-lead ECG in predicting the mutation carrier state in families with LQTS |
| |
Language
|
|
|
|
English
| |
Source (journal)
|
|
|
|
Heart rhythm
| |
Publication
|
|
|
|
2017
| |
ISSN
|
|
|
|
1547-5271
| |
DOI
|
|
|
|
10.1016/J.HRTHM.2016.11.034
| |
Volume/pages
|
|
|
|
14
:3
(2017)
, p. 376-382
| |
ISI
|
|
|
|
000397243700015
| |
Pubmed ID
|
|
|
|
28212739
| |
Full text (Publisher's DOI)
|
|
|
|
| |
Full text (publisher's version - intranet only)
|
|
|
|
| |
|