The E1784K mutation in SCN5A is associated with mixed clinical phenotype of type 3 long QT syndrome
J. Clin. Invest. Naomasa Makita, et al. 118:2219 doi:10.1172/JCI34057 [Go to this article.]

Figure 2
ECG characteristics of E1784K mutation carriers. (A) QT prolongation (QTc, 470 ms) and spontaneous saddleback type ST elevation observed in the right precordial leads in carrier A;II:1. (B) ECG recordings before and after the Na channel blocker provocation test. Pilsicainide (left, patient K;II:1) induced coved-type ST elevation in V1 and the QTc was concomitantly shortened (QTc: control, 495 ms; pilsicainide, 459 ms). Ajmaline (right, patient A;III:9) also induced coved-type ST elevation in V1 and V2 and QTc shortening (control, 501 ms; ajmaline, 490 ms). (C) Sinus node dysfunction (SND) demonstrated by a 3.9-s sinus arrest in carrier A;I:1. (D) A Venn diagram representing electrophysiological manifestation of 41 SCN5A-E1784K mutation carriers. Thirty-eight carriers exhibited an abnormally long QTc, 3 individuals had a normal QTc, and 1 exhibited sinus node dysfunction only. Sinus node dysfunction and BrS were observed in 16 and 9 individuals, respectively, with 4 displaying both phenotypes.