Tomas Robyns1, Rik Willems2, Bert Vandenberk2, Joris Ector2, Christophe Garweg2, Cuno Kuiperi3, Jeroen Breckpot3, Anniek Corveleyn3, Stefan Janssens2, Hein Heidbuchel4, Dieter Nuyens5. 1. Department of Cardiovascular Diseases, University Hospitals Leuven, Leuven, Belgium; Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium. Electronic address: Tomas.Robyns@uzleuven.be. 2. Department of Cardiovascular Diseases, University Hospitals Leuven, Leuven, Belgium; Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium. 3. Department of Human Genetics, University Hospitals Leuven, Leuven, Belgium. 4. Department of Cardiovascular Diseases, University Hospitals Leuven, Leuven, Belgium; Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium; Department of Cardiology, University Hospitals Antwerp, Antwerp, Belgium. 5. Department of Cardiovascular Diseases, University Hospitals Leuven, Leuven, Belgium; Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium; Department of Cardiology, Ziekenhuis Oost Limburg Genk, Genk, Belgium.
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. Copyright Â
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. Copyright Â
Authors: Pia Dahlberg; Ulla-Britt Diamant; Thomas Gilljam; Annika Rydberg; Lennart Bergfeldt Journal: Ann Noninvasive Electrocardiol Date: 2020-10-18 Impact factor: 1.468
Authors: Irena Andršová; Katerina Hnatkova; Martina Šišáková; Ondřej Toman; Peter Smetana; Katharina M Huster; Petra Barthel; Tomáš Novotný; Georg Schmidt; Marek Malik Journal: Front Physiol Date: 2022-02-07 Impact factor: 4.566
Authors: Simona Aufiero; Hidde Bleijendaal; Tomas Robyns; Bert Vandenberk; Christian Krijger; Connie Bezzina; Aeilko H Zwinderman; Arthur A M Wilde; Yigal M Pinto Journal: BMC Med Date: 2022-05-03 Impact factor: 11.150
Authors: Florine A Berger; Willem van Weteringen; Heleen van der Sijs; Nicole G M Hunfeld; Jeroen J H Bunge; Natasja M S de Groot; Patricia M L A van den Bemt; Teun van Gelder Journal: Pharmacol Res Perspect Date: 2021-12