Almost half of sudden cardiac deaths can be attributed to a previously undiagnosed, or ‘silent’, myocardial infarction, a Finnish study has found.

The findings, published in JAMA Cardiology, also suggest that some of these deaths could have been prevented based on pre-mortem ECG readings, the researchers say.

In a cohort study of nearly 6000 adults (mean age 65) from the Finnish Genetic Study of Arrhythmic Events who were verified to have had sudden cardiac death between 1998 and 2017, the researchers compared autopsy findings and ECG abnormalities to determine the prevalence of silent MI.

The condition was defined as a scar detected by macro- and microscopic evaluation of the myocardium without previously diagnosed coronary artery disease. ECG data was available for 438 individuals.