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QTc prolongation in patients with hearing loss: Electrocardiographic and genetic study
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Abstract
Background: The aim of the study was to determine, whether electrocardiogram (ECG) screening could reduce the risk of sudden cardiac death in patients with hearing loss through the early diagnosis of Jervell and Lange-Nielsen syndrome and the introduction of the therapy.
Methods: One thousand and eighty patients with hearing loss (aged 21.8 ± 19.9 years) underwent ECG. Additionally, all subjects were asked to complete a 3-question survey. Those who met, at least, one of the high-risk criteria underwent further cardiac assessment and genetic testing.
Results: QTc assessment was possible in 1,027 patients. Mean QTc measured 422.8 ± 23.7 ms in 313 women, 414.9 ± 27.7 ms in 273 men and 421.1 ± 21.5 ms in 441 children (individuals younger than 14 years). Abnormal QTc was found in 13 (4.1%) women, 20 (7.3%) men, and 72 (16.3%) children. In the studied group, no recessive mutation of KNCQ1 or KCNE1 was found. In 6 patients, other mutations were found: in KCNQ1 (n = 1), in KCNH2 (n = 3) and in SCN5A (n = 1), which were pathogenic for long-QT-syndromes (LQTS), and 2 mutations of unknown clinical significance in SCN5A. Overall, out of these 6 patients LQTS was diagnosed in 3 asymptomatic patients, but with abnormal QTc and in 2 patients with normal QTc, but who were previously treated for epilepsy.
Conclusions: Jervell and Lange-Nielsen syndrome is a very rare condition even in a population with hearing loss. In this population, the prevalence of prolonged QT interval is increased over the general population. Further investigations are necessary.
Abstract
Background: The aim of the study was to determine, whether electrocardiogram (ECG) screening could reduce the risk of sudden cardiac death in patients with hearing loss through the early diagnosis of Jervell and Lange-Nielsen syndrome and the introduction of the therapy.
Methods: One thousand and eighty patients with hearing loss (aged 21.8 ± 19.9 years) underwent ECG. Additionally, all subjects were asked to complete a 3-question survey. Those who met, at least, one of the high-risk criteria underwent further cardiac assessment and genetic testing.
Results: QTc assessment was possible in 1,027 patients. Mean QTc measured 422.8 ± 23.7 ms in 313 women, 414.9 ± 27.7 ms in 273 men and 421.1 ± 21.5 ms in 441 children (individuals younger than 14 years). Abnormal QTc was found in 13 (4.1%) women, 20 (7.3%) men, and 72 (16.3%) children. In the studied group, no recessive mutation of KNCQ1 or KCNE1 was found. In 6 patients, other mutations were found: in KCNQ1 (n = 1), in KCNH2 (n = 3) and in SCN5A (n = 1), which were pathogenic for long-QT-syndromes (LQTS), and 2 mutations of unknown clinical significance in SCN5A. Overall, out of these 6 patients LQTS was diagnosed in 3 asymptomatic patients, but with abnormal QTc and in 2 patients with normal QTc, but who were previously treated for epilepsy.
Conclusions: Jervell and Lange-Nielsen syndrome is a very rare condition even in a population with hearing loss. In this population, the prevalence of prolonged QT interval is increased over the general population. Further investigations are necessary.
Keywords
long-QT syndrome, hearing loss, Jervell and Lange-Nielsen syndrome, electrocardiogram


Title
QTc prolongation in patients with hearing loss: Electrocardiographic and genetic study
Journal
Issue
Pages
34-41
Published online
2015-09-23
Page views
2201
Article views/downloads
1891
DOI
10.5603/CJ.a2015.0062
Pubmed
Bibliographic record
Cardiol J 2016;23(1):34-41.
Keywords
long-QT syndrome
hearing loss
Jervell and Lange-Nielsen syndrome
electrocardiogram
Authors
Agnieszka Sanecka
Elżbieta Katarzyna Biernacka
Małgorzata Szperl
Magdalena Sosna
Małgorzata Mueller-Malesińska
Urszula Kozicka
Rafał Baranowski
Agnieszka Kosiec
Hubert Łazarczyk
Henryk Skarżyński
Piotr Hoffman
Katarzyna Bieganowska
Ryszard Piotrowicz