scholarly journals Pediatric Cohort With Long QT Syndrome　– KCNH2 Mutation Carriers Present Late Onset But Severe Symptoms –

2016 ◽  
Vol 80 (3) ◽  
pp. 696-702 ◽  
Author(s):  
Junichi Ozawa ◽  
Seiko Ohno ◽  
Takashi Hisamatsu ◽  
Hideki Itoh ◽  
Takeru Makiyama ◽  
...  
Keyword(s):  
Long Qt Syndrome ◽  
Late Onset ◽  
Long Qt ◽  
Mutation Carriers ◽  
Qt Syndrome

Abstract 16509: Young Long QT Syndrome Patients With KCNH2 Mutations Have Late Onset but Severe Symptoms

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Junichi Ozawa ◽  
Seiko Ohno ◽  
Hideki Itoh ◽  
Takeru Makiyama ◽  
Minoru Horie
Keyword(s):  
Long Qt Syndrome ◽  
Age Of Onset ◽  
Late Onset ◽  
Torsades De Pointes ◽  
Preventive Therapy ◽  
Cardiac Events ◽  
Long Qt ◽  
Mutation Carriers ◽  
Age Related ◽  
Qt Syndrome

Introduction: The long QT syndrome (LQTS) is one of the causes of sudden cardiac death in children. Although the risk factors for cardiac events depending on the genotype have been reported, age-related difference in phenotype remains unknown. Objectives: We aimed to clarify the age-and genotype-related clinical features in the young LQTS cohort (form 1 to 20y.o.). Methods and Results: This study comprised 101 symptomatic LQTS patients that were genotyped (male n=36, mean age 10.6±4.3). We excluded patients with multiple mutations. Fifty patients carried heterozygous mutations in KCNQ1, 48 in KCNH2 and 3 in SCN5A. LQTS-related cardiac events were classified into 3 categories; syncope, documented Torsades de pointes (TdP) and cardio-pulmonary arrest (CPA). Ninety patients experienced syncope, 7 were documented TdP and 4 suffered CPA. Figure shows a frequency histogram for the ages of first event in each genotype. The mean age of the onset in KCNH2 mutation carriers were significantly older (12.2±4.6y.o.) than those in KCNQ1 (9.2±3.5y.o., p<0.001). The numbers and mean ages of the patients suffered CPA were 1 in KCNQ1 (12y.o.), 2 in KCNH2 (10.5±3.5y.o.) and 1 in SCN5A (6y.o.). TdP was significantly more frequently documented in the patients with KCNH2 mutations (n=6, 13.7±3.3y.o.) than those with KCNQ1 mutations (n=1, 9y.o., p=0.029). Conclusion: In the young LQTS patients, therefore, KCNH2 mutation carriers showed a severer phenotype than those of KCNQ1, though their age of onset was older. These finding helped us to choose more appropriate preventive therapy depend on the age of onset and genotype.

scholarly journals Epinephrine Bolus Test in Detecting Long QT Syndrome Mutation Carriers with Indeterminable Electrocardiographic Phenotype

2011 ◽  
Vol 16 (2) ◽  
pp. 172-179 ◽  
Author(s):  
Anna-Mari Hekkala ◽  
Heikki Swan ◽  
Matti Viitasalo ◽  
Heikki Väänänen ◽  
Lauri Toivonen
Keyword(s):  
Long Qt Syndrome ◽  
Long Qt ◽  
Mutation Carriers ◽  
Qt Syndrome

Type 1 long QT syndrome and psychological stress in a laboratory setting

2018 ◽  
Vol 25 (9) ◽  
pp. 1213-1221 ◽  
Author(s):  
Ilmari Määttänen ◽  
Niklas Ravaja ◽  
Pentti Henttonen ◽  
Sampsa Puttonen ◽  
Kristian Paavonen ◽  
...  
Keyword(s):  
Stress Responses ◽  
Long Qt Syndrome ◽  
Mental Stress ◽  
Mental Arithmetic ◽  
Physiological Stress ◽  
Long Qt ◽  
Mutation Carriers ◽  
Asymptomatic Patients ◽  
Qt Syndrome

Trait-like sensitivity to stress in long QT syndrome patients has been documented previously. In addition, mental stress has been associated with symptomatic status of long QT syndrome. We examined whether the symptomatic type 1 long QT syndrome patients would be more sensitive to mental stress compared to asymptomatic patients and whether there would be differences in task-related physiological stress reactions between type 1 long QT syndrome patients and healthy individuals. The study population consisted of 21 symptomatic and 23 asymptomatic molecularly defined KCNQ1 mutation carriers, their 32 non-carrier relatives and 46 non-related healthy controls, with mean ages of 37, 39, 35 and 23 years, respectively. Electrocardiography was utilised to calculate inter-beat interval and high frequency and low frequency heart rate variability. Blood pressure was measured and mean arterial pressure and pulse pressure were calculated. Stress was induced using three different tasks: mental arithmetic, reaction time and public speech. Stress responses of symptomatic and asymptomatic type 1 long QT syndrome patients were not statistically different in any of the stress tasks. Short-term physiological stress reactivity of symptomatic type 1 long QT syndrome patients appears to be normal and does not enhance the risk assessment of asymptomatic mutation carriers.

Brief report: Emotional distress and recent stressful life events in long QT syndrome mutation carriers

2013 ◽  
Vol 20 (11) ◽  
pp. 1445-1450 ◽  
Author(s):  
Ilmari Määttänen ◽  
Markus Jokela ◽  
Laura Pulkki-Råback ◽  
Liisa Keltikangas-Järvinen ◽  
Heikki Swan ◽  
...  
Keyword(s):  
Life Events ◽  
Emotional Distress ◽  
Long Qt Syndrome ◽  
Stressful Life Events ◽  
Stressful Life ◽  
Long Qt ◽  
Mutation Carriers ◽  
Qt Syndrome

Long QT syndrome and associated gene mutation carriers in Japanese children: results from ECG screening examinations

2009 ◽  
Vol 117 (12) ◽  
pp. 415-424 ◽  
Author(s):  
Kenshi Hayashi ◽  
Noboru Fujino ◽  
Katsuharu Uchiyama ◽  
Hidekazu Ino ◽  
Kenji Sakata ◽  
...  
Keyword(s):  
Ion Channel ◽  
Long Qt Syndrome ◽  
High Probability ◽  
Dominant Negative ◽  
Carrier Status ◽  
Japanese Children ◽  
Long Qt ◽  
Mutation Carriers ◽  
Qt Intervals ◽  
Qt Syndrome

LQTS (long QT syndrome) is caused by mutations in cardiac ion channel genes; however, the prevalence of LQTS in the general population is not well known. In the present study, we prospectively estimated the prevalence of LQTS and analysed the associated mutation carriers in Japanese children. ECGs were recorded from 7961 Japanese school children (4044 males; mean age, 9.9±3.0 years). ECGs were examined again for children who had prolonged QTc (corrected QT) intervals in the initial ECGs, and their QT intervals were measured manually. An LQTS score was determined according to Schwartz's criteria, and ion channel genes were analysed. In vitro characterization of the identified mutants was performed by heterologous expression experiments. Three subjects were assigned to a high probability of LQTS (3.5≤ LQTS score), and eight subjects to an intermediate probability (1.0< LQTS score ≤3.0). Genetic analysis of these II subjects identified three KCNH2 mutations (M124T, 547–553 del GGCGGCG and 2311–2332 del/ins TC). In contrast, no mutations were identified in the 15 subjects with a low probability of LQTS. Electrophysiological studies showed that both the M124T and the 547–553 del GGCGGCG KCNH2 did not suppress the wild-type KCNH2 channel in a dominant-negative manner. These results demonstrate that, in a random sample of healthy Japanese children, the prevalence of a high probability of LQTS is 0.038% (three in 7961), and that LQTS mutation carriers can be identified in at least 0.038% (one in 2653). Furthermore, large-scale genetic studies will be needed to clarify the real prevalence of LQTS by gene-carrier status, as it may have been underestimated in the present study.

T-wave morphology after epinephrine bolus may reveal silent long QT syndrome mutation carriers

2012 ◽  
Vol 45 (4) ◽  
pp. 368-372 ◽  
Author(s):  
Anna-Mari Hekkala ◽  
Heikki Väänänen ◽  
Heikki Swan ◽  
Matti Viitasalo ◽  
Lauri Toivonen
Keyword(s):  
Long Qt Syndrome ◽  
Long Qt ◽  
T Wave ◽  
Mutation Carriers ◽  
Wave Morphology ◽  
Qt Syndrome

scholarly journals Late-onset severe long QT syndrome

2017 ◽  
Vol 23 (4) ◽  
pp. e12517
Author(s):  
Babken Asatryan ◽  
André Schaller ◽  
Deborah Bartholdi ◽  
Argelia Medeiros-Domingo
Keyword(s):  
Long Qt Syndrome ◽  
Late Onset ◽  
Long Qt ◽  
Qt Syndrome
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