Temporal variability of T-wave morphology and risk of sudden cardiac death in patients with coronary artery disease.

ABSTRACT

BACKGROUND: The possible relationship between temporal variability of electrocardiographic spatial heterogeneity of repolarization and the risk of sudden cardiac death (SCD) in patients with coronary artery disease (CAD) is not completely understood. METHODS: The standard deviation of T-wave morphology dispersion (TMD-SD), of QRST angle (QRSTA-SD), and of T-wave area dispersion (TW-Ad-SD) were analyzed on beat-to-beat basis from 10 min period of the baseline electrocardiographic recording in ARTEMIS study patients with angiographically verified CAD. RESULTS: After on average of 8.6 ± 2.3 years of follow-up, a total of 66 of the 1,678 present study subjects (3.9%) had experienced SCD or were resuscitated from sudden cardiac arrest (SCA). TMD-SD was most closely associated with the risk for SCD and was significantly higher in patients who had experienced SCD/SCA compared with those who remained alive (3.61 ± 2.83 vs. 2.64 ± 2.52, p = .008, respectively), but did not differ significantly between the patients who had experienced non-SCD (n = 71, 4.2%) and those who remained alive (3.20 ± 2.73 vs. 2.65 ± 2.53, p = .077, respectively) or between the patients who succumbed to non-cardiac death (n = 164, 9.8%) and those who stayed alive (2.64 ± 2.17 vs. 2.68 ± 2.58, p = .853). After adjustments with relevant clinical risk indicators of SCD/SCA, TMD-SD still predicted SCD/SCA (HR 1.107, 95% CIs 1.035-1.185, p = .003). CONCLUSIONS: Temporal variability of electrocardiographic spatial heterogeneity of repolarization represented by TMD-SD independently predicts long-term risk of SCD/SCA in patients with CAD.