Primordial symptoms and electrocardiogram among sudden cardiac death victims due to primary myocardial fibrosis

Background. Sudden cardiac death (SCD) remains a major cause of death despite progress in prevention and intervention of cardiac diseases. The most common cause of non-ischemic SCD in young individuals in Northern Finland is primary myocardial fibrosis (PMF). Methods. Fingesture study consists of 5,869 systematically autopsied subjects with SCD from Northern Finland collected from 1998 to 2017. Nonischemic etiology was the cause of SCD in 1477 (25%) subjects out of which primary myocardial fibrosis was the cause of SCD in 184 (12%) subjects (65% men, median age 55±16 years). Medico-legal autopsies in PMF subjects showed no other noncardiac organ changes or prior diseases that could have caused myocardial fibrosis detected at gross dissection and histological analyses. We examined the ante mortem ECG and medical history of the subjects to discover preceding symptoms and ECG changes. Results. Prior health care contact in electronic health record system was found for 89 (48%) subjects and ECG was available for 52 (28%) subjects; 20 subjects both medical history and ECG were available. We observed that transient loss of consciousness (TLOC) was the most common symptom recorded and was reported by 33 (37%) subjects. ECG was abnormal in 38 (73%) subjects. Fragmented QRS (fQRS) complex was found in 26 (50%) subjects. Other ECG findings were prolonged QTc (>450ms in men and >470ms in women) in 10 (19%), T-inversions in 4 (8%), pathological Q-waves in 3 (6%), and prolonged QRS (> 110 ms) in 3 subjects. Vast majority, 87% of subjects had either TLOC or abnormal ECG. Only 7 subjects with ECG or ERS history available had normal ECG and did not have previous TLOC. Conclusions. Most subjects with PMF had abnormal ECG or previous TLOC. The results suggest that the combination should generate careful cardiovascular examination in order to detect underlying myocardial disease and possibly prevent SCD.