3254Manifestations of myocardial fibrosis in the standard 12-lead electrocardiogram

• Published in: European heart journal Vol. 40; no. Supplement_1
• Main Authors: Holmstrom, L, Kentta, T, Haukilahti, A, Pakanen, L, Huikuri, H, Junttila, M J
• Format: Journal Article
• Language: English
• Published: Oxford University Press 01.10.2019
• Subjects: Ventricular Arrhythmias and SCD - Clinical
• ISSN: 0195-668X; 1522-9645
• DOI: 10.1093/eurheartj/ehz745.0046

Abstract Background Myocardial fibrosis has substantial role in sudden cardiac deaths (SCD). Major challenge in preventing SCDs is early recognition of vulnerable patients with fibrotic cardiomyopathy. Our aim was to find manifestations of myocardial fibrosis in 12-lead electrocardiogram (ECG). Methods Study population is based on the Fingesture study, which has gathered data from 5,869 consecutive autopsied SCD victims between 1998 and 2017 in Finland. The degree of fibrosis was determined based on the histological samples taken from the heart during autopsy and was categorized into four groups; 1) no fibrosis, 2) scattered mild fibrosis, 3) moderate patchy fibrosis and 4) substantial fibrosis. We were able to collect pre-mortem 12-lead ECGs from 1,100 SCD victims. Ischemic cardiomyopathy was the cause of death in 689 cases and 411 had nonischemic cardiomyopathy at autopsy in the group where ECG was available. Results Mean age of the study subjects was 66±13 years and 75% were male. At least some amount of myocardial fibrosis was present in 92% of the victims. QRS duration in ECG correlated with the degree of fibrosis in autopsy as follows; 96±21ms in group 1 (n=93), 97±20ms in group 2 (n=357), 103±26ms in group 3 (n=506) and 108±27ms in group 4 (n=144; p<0.001, β=0.153). Prevalence of fragmented QRS complex was higher among victims with severe fibrosis (40% in group 1, 43% in group 2, 60% in group 3 and 65% in group 4; p<0.001). Additionally, inferolateral T-wave inversions were more common in groups with increasing amount of myocardial fibrosis (5.4% in group 1, 13.2% in group 2, 20.4% in group 3 and 31.9% in group 4; p<0.001). Associations were visible in both ischemic and nonischemic SCDs but reached statistical significance only among ischemic SCD victims. Heart rate corrected JT interval and Sokolow-Lyon index had no linear correlation with the degree of fibrosis. Conclusions Myocardial fibrosis was associated with QRS prolongation, T-wave inversions and QRS fragmentation among SCD victims. Fibrosis did not manifest as clearly in ECG among patients with nonischemic cardiomyopathies as among ischemic SCD victims. The results may explain the increased risk for SCD in patients with abnormal QRS complex or inverted T waves providing means for recognizing patients with underlying fibrotic cardiomyopathy. Acknowledgement/Funding Sigrid Juselius Foundation, Foundation of Cardiac Research, Paavo Nurmi Foundation and Paulo foundation, Finland