Markers of Sudden Cardiac Death Associated with the Ventricular-Paced 12-Lead ECG

Introduction ECG markers are associated with increased risk of sudden cardiac arrest (SCA) on the sinus rhythm ECG. A sizeable subgroup of patients at risk receives cardiac implantable electrical devices, but there are no known markers of SCA risk on the ventricular-paced (VP) ECG. Methods We conducted a case-control analysis within a community-based SCA study in Oregon USA (2002–2020; ∼1 million catchment population) with validation in an identically designed study in California USA (2015-2023; ∼850,000 catchment population). SCA cases included adults (≥18years) with archived VP ECGs obtained prior and unrelated to their SCA. Controls met the same ECG criteria but without history of ventricular arrhythmias or SCA. Results The discovery analysis included 158 participants (119 SCA, 39 controls), mean age 76.9±11.8 years. SCA cases had a higher ventricular rate (74.9±16.0bpm vs. 69.3±12.0bpm, p=0.05), longer corrected QT interval (QTc; 525.9±49.9ms vs. 493.9± 31.0ms, p<0.001) and longer Tpeak-Tend (Tpe; 111.8±23.3ms vs. 95.9±20.1ms, p<0.001). After adjustment, QTc and Tpe were significantly associated with SCA, with adjusted ORs 6.1 (95%CI: 1.4–26.2) and 7.9 (95%CI: 2.0–31.0) in the discovery population, and 6.1 (95%CI: 2.5–14.8) and 3.7 (95%CI: 1.6–8.6) in the validation population. In pooled analysis, the model combining QTc and Tpe achieved an AUC of 0.752, significantly outperforming each individually. Subjects with both prolonged QTc and Tpe had a 16-fold higher risk (adjusted OR:16.2, 95%CI: 6.0–43.6) compared to those without abnormalities. Conclusion Abnormal myocardial repolarization measured by QTc and Tpe was independently associated with SCA. These findings suggest that the VP ECG could also predict SCA risk.