Long QT syndrome genotyping by electrocardiography: fact, fiction, or something in between?
Diagnosis of long QT syndrome (LQTS) is difficult. A prolonged QT interval is easily overlooked, and in 10% of all patients with LQTS, the QT interval is normal. Genotyping is unfortunately not able to detect all patients and healthy subjects correctly. Although QT prolongation is the most used risk parameter, there is no clear correlation between the prolonged QT interval and the risk of arrhythmias in drug-induced LQTS. Quantification of T-wave morphology is a promising method that is able to provide more information about repolarization than QT prolongation alone. It is a fact that ECG evaluation can serve as a guide for genotyping and can reduce the costs by suggesting which gene to start sequencing, but it is fiction that the ECG can replace genotyping.
Kanters
Jørgen K
JK
Laboratory of Experimental Cardiology, Department of Medical Physiology, University of Copenhagen, DK2200 Copenhagen N, Denmark. jkanters@mfi.ku.dk
Graff
Claus
C
Andersen
Mads P
MP
Hardahl
Thomas
T
Toft
Egon
E
Christiansen
Michael
M
Bloch Thomsen
Poul Erik
PE
Struijk
Johannes J
JJ
D015220:Calcium Channels / Q000235:genetics*; D002986:Clinical Trials as Topic; D004562:Electrocardiography / Q000379:methods*; D019317:Evidence-Based Medicine; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D005820:Genetic Testing / Q000379:methods*; D005838:Genotype; D006801:Humans; D008133:Long QT Syndrome / Q000175:diagnosis* / Q000235:genetics*; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D012680:Sensitivity and Specificity
D015220:Calcium Channels