OBJECTIVES: The aim was to investigate at what age electrocardiographic characteristics of long QT syndrome type 3 (LQT3) and Brugada syndrome (BS), based on a single SNC5A mutation, appear. BACKGROUND: The QT interval (QT) in LQT3 is prolonged during bradycardia. It is not clear yet if this is obvious in young children with a relative fast heart rate (HR). METHODS: Thirty-six children with an SNC5A gene mutation (1795insD) and 46 non-carrier siblings were investigated. In different age groups, HR, QT, QTc, and ST-segment elevation on a 12-lead electrocardiogram (ECG), and HR, QT, QTc, and DeltaQT after the longest pause in a Holter (recording) were evaluated. RESULTS: In all age groups, HR at rest tended to be lower in carriers than in non-carriers, and QT was longer in carriers than in non-carriers. The Brugada phenotype was found >5 years. Gender specific differences were not identified. The QT at lower HR and DeltaQT were longer in carriers than in non-carriers. A QTc of > or =0.44 s at the lowest HR (sensitivity 100%; specificity 88.4%) and DeltaQT > or =60 ms (sensitivity 100%; specificity 82.6%) were good predictors for having LQT3. CONCLUSIONS: We conclude that electrocardiographic characteristics of LQT3 and BS show age-dependent penetrance. A QT prolongation and conduction disease were present from birth onwards, whereas ST-segment elevation only developed >5 years. Good tools for clinical diagnosis of LQT3 in this family are QTc at the lowest HR and DeltaQT after a pause in a Holter, even at very young age.
OBJECTIVES: The aim was to investigate at what age electrocardiographic characteristics of long QT syndrome type 3 (LQT3) and Brugada syndrome (BS), based on a single SNC5A mutation, appear. BACKGROUND: The QT interval (QT) in LQT3 is prolonged during bradycardia. It is not clear yet if this is obvious in young children with a relative fast heart rate (HR). METHODS: Thirty-six children with an SNC5A gene mutation (1795insD) and 46 non-carrier siblings were investigated. In different age groups, HR, QT, QTc, and ST-segment elevation on a 12-lead electrocardiogram (ECG), and HR, QT, QTc, and DeltaQT after the longest pause in a Holter (recording) were evaluated. RESULTS: In all age groups, HR at rest tended to be lower in carriers than in non-carriers, and QT was longer in carriers than in non-carriers. The Brugada phenotype was found >5 years. Gender specific differences were not identified. The QT at lower HR and DeltaQT were longer in carriers than in non-carriers. A QTc of > or =0.44 s at the lowest HR (sensitivity 100%; specificity 88.4%) and DeltaQT > or =60 ms (sensitivity 100%; specificity 82.6%) were good predictors for having LQT3. CONCLUSIONS: We conclude that electrocardiographic characteristics of LQT3 and BS show age-dependent penetrance. A QT prolongation and conduction disease were present from birth onwards, whereas ST-segment elevation only developed >5 years. Good tools for clinical diagnosis of LQT3 in this family are QTc at the lowest HR and DeltaQT after a pause in a Holter, even at very young age.
Authors: Martina Comelli; Marianna Meo; Daniel O Cervantes; Emanuele Pizzo; Aaron Plosker; Peter J Mohler; Thomas J Hund; Jason T Jacobson; Olivier Meste; Marcello Rota Journal: Am J Physiol Heart Circ Physiol Date: 2020-09-04 Impact factor: 4.733
Authors: Krekwit Shinlapawittayatorn; Xi X Du; Haiyan Liu; Eckhard Ficker; Elizabeth S Kaufman; Isabelle Deschênes Journal: Heart Rhythm Date: 2010-11-23 Impact factor: 6.343
Authors: Kirstine Calloe; Nicole Schmitt; Soren Grubb; Ryan Pfeiffer; Jens-Peter David; Ronald Kanter; Jonathan M Cordeiro; Charles Antzelevitch Journal: Can J Physiol Pharmacol Date: 2011-09-06 Impact factor: 2.273
Authors: P G Postema; M Van den Berg; J P Van Tintelen; F Van den Heuvel; M Grundeken; N Hofman; W P Van der Roest; E A Nannenberg; I P C Krapels; C R Bezzina; A Wilde Journal: Neth Heart J Date: 2009-11 Impact factor: 2.380