Objective A major challenge in reducing the incidence of sudden cardiac death (SCD) is the identification of patients at risk. Myocardial fibrosis has a substantial association with SCD risk but is difficult to identify among general populations. Our aim was to find electrocardiographic (ECG) markers of myocardial fibrosis among SCD victims.
Methods Study population was acquired from the Fingesture study, which has gathered data from 5869 consecutive autopsied SCD victims in Northern Finland between 1998 and 2017. The degree of fibrosis was determined in histological samples taken from the heart during autopsy and was categorised into four groups: (1) no fibrosis, (2) scattered mild fibrosis, (3) moderate patchy fibrosis and (4) substantial fibrosis. We were able to collect ECGs from 1100 SCD victims.
Results The mean age of the study subjects was 66±13 years and 75% were male. QRS duration in ECG correlated with the degree of fibrosis (p<0.001, β=0.153). Prevalence of fragmented QRS complex, pathological Q waves and T wave inversions correlated with increased degree of fibrosis (p<0.001 in each). Depolarisation abnormalities were observed both in ischaemic and non-ischaemic heart disease. Repolarisation abnormalities reached statistical significance only among ischaemic SCD victims. An abnormal ECG was observed in 75.3% of the subjects in group 1, 73.7% in group 2, 88.5% in group 3 and 91.7% in group 4 patients (p<0.001).
Conclusions Myocardial fibrosis was associated with QRS prolongation, deep Q waves, T wave inversions and QRS fragmentation. The results provide potentially useful non-invasive early recognition of patients with fibrotic cardiomyopathy and risk of SCD.
- cardiac arrhythmias and resuscitation science
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Contributors Study design and conception: RJM, HVH and JJ. Acquisition, analysis or interpretation of data: LH, AH, JV, TK, HA, LP, RJM, HVH and JJ. Drafting of the manuscript: LH and JJ. Statistical analysis: LH, AH, TK and AK. Critical revision of the manuscript for important intellectual content: AH, JV, TK, LP, RJM, HVH and JJ. Obtained funding: JJ. Supervision: HVH and JJ. Guarantors: LH and JJ.
Funding The study was supported by Sigrid Juselius Foundation, Finnish Foundation for Cardiovascular Research, Yrjö Jahnsson Foundation, Paavo Nurmi Foundation, Paulo Foundation, Aarne Koskelo Foundation, Finnish Medical Foundation, Aatos and Jane Erkko Foundation.
Competing interests None declared.
Patient and public involvement Patients and/or the public were not involved in the design, or conduct, or reporting, or dissemination plans of this research.
Patient consent for publication Not required.
Provenance and peer review Not commissioned; externally peer reviewed.
Data availability statement No data are available. All data relevant to the study are included in the article or uploaded as supplementary information.
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