Electrocardiographic features in Andersen-Tawil syndrome patients with KCNJ2 mutations - Characteristic T-U-wave patterns predict the KCNJ2 genotype

Article

关键词: LONG-QT SYNDROME;    PERIODIC PARALYSIS;    VENTRICULAR-TACHYCARDIA;    REPOLARIZATION;    CURRENTS;    KIR2.1;    ARRHYTHMIAS;    PHENOTYPES;    CHANNELS;    SPECTRUM;   

DOI  :  10.1161/CIRCULATIONAHA.104.472498

来源: SCIE

【 摘 要 】

Background - The ECG features of Andersen-Tawil syndrome (ATS) patients with KCNJ2 mutations ( ATS1) have not been systematically assessed. This study aimed to define ECG features of KCNJ2 mutation carriers, to determine whether characteristic T-U - wave patterns exist, and to establish whether T-U patterns predict the ATS1 genotype. Methods and Results - In phase I, evaluation of T-U morphology in ECGs of 39 KCNJ2 mutation carriers identified characteristic T-U patterns: prolonged terminal T downslope, wide T-U junction, and biphasic and enlarged U waves. In phase II, ATS1 genotype prediction by T-U pattern was evaluated in the next 147 ECGs ( 57 other KCNJ2 mutation carriers, 61 unaffected family members, and 29 ATS patients without KCNJ2 mutations), with a sensitivity of 84% and specificity of 97%. Characteristic T-U patterns were present in 91% (87/96), in whom an enlarged U wave was predominant (73%). In phase III, QTc, QUc, and T- and U-wave duration/amplitude were compared in the 96 ATS1, 29 non-KCNJ2 ATS, and 75 normal subjects. In ATS1 patients, QUc, U-wave duration and amplitude, and QTc were all increased (P < 0.001), but median QTc and interquartile range (IQR) were just 440 ms ( IQR, 28 ms) compared with 420 ms (IQR, 20 ms) in normal subjects and 425 ms (IQR, 48 ms) in ATS non-KCNJ2 patients. Conclusions - In ATS1 patients, gene-specific T-U-wave patterns resulting from decreased I-K1 owing to KCNJ2 mutations can aid diagnosis and direct genotyping. The normal QTc, distinct ECG, and other clinical features distinguish ATS1 from long-QT syndrome, and it is best designated as ATS1 rather than LQT7.

【 授权许可】

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