Clinical value of electrocardiographic parameters in genotyped individuals with familial long QT syndrome.
Rate corrected QT interval (QTc) and QT dispersion (QTd) have been suggested as markers of an increased propensity to arrhythmic events and efficacy of therapy in patients with long QT syndrome (LQTS). To evaluate whether QTc and QTd correlate to genetic status and clinical symptoms in LQTS patients and their relatives, ECGs of 116 genotyped individuals were analyzed. JTc and QTc were longest in symptomatic patients (n = 28). Both QTd and JTd were significantly higher in symptomatic patients than in asymptomatic (n = 29) or unaffected family members (n = 59). The product of QTd/JTd and QTc/JTc was significantly different among all three groups. Both dispersion and product put additional and independent power on identification of mutation carriers when adjusted for sex and age in a logistic regression analysis. Thus, symptomatic patients with LQTS show marked inhomogenity of repolarization in the surface ECG. QT dispersion and QT product might be helpful in finding LQTS mutation carriers and might serve as additional ECG tools to identify asymptomatic LQTS patients.
Moennig
G
G
Department of Cardiology and Angiology, Westfälische Wilhelms-University Münster, Albert-Schweitzer-Str. 33, D-48149 Münster, Germany. moennig@uni-muenster.de
Schulze-Bahr
E
E
Wedekind
H
H
Borggrefe
M
M
Funke
H
H
Toelle
M
M
Kirchhof
P
P
Eckardt
L
L
Assmann
G
G
Breithardt
G
G
Haverkamp
W
W
D000328:Adult; D027682:Cation Transport Proteins; D004268:DNA-Binding Proteins; D000072237:ERG1 Potassium Channel; D004562:Electrocardiography; D051638:Ether-A-Go-Go Potassium Channels; D005260:Female; D006580:Genetic Carrier Screening; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006801:Humans; D051656:KCNQ Potassium Channels; D051657:KCNQ1 Potassium Channel; D008133:Long QT Syndrome / Q000175:diagnosis / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics; D015221:Potassium Channels / Q000235:genetics; D024642:Potassium Channels, Voltage-Gated; D011237:Predictive Value of Tests; D012307:Risk Factors; D015534:Trans-Activators; D000071230:Transcriptional Regulator ERG
D027682:Cation Transport Proteins; D004268:DNA-Binding Proteins; C072312:ERG protein, human; D000072237:ERG1 Potassium Channel; D051638:Ether-A-Go-Go Potassium Channels; C092509:KCNH6 protein, human; D051656:KCNQ Potassium Channels; D051657:KCNQ1 Potassium Channel; C496909:KCNQ1 protein, human; D015221:Potassium Channels; D024642:Potassium Channels, Voltage-Gated; D015534:Trans-Activators; D000071230:Transcriptional Regulator ERG