A new system for classification of cardiac death as arrhythmic, ischemic, or due to myocardial pump failure

Existing classifications of cardiac death fail to incorporate current understanding of the pathophysiology of sudden cardiac death. We developed a new scheme for classifying cardiac death that defines 3 categories of underlying mechanism: primary arrhythmia, acute myocardial ischemia/infarction, and myocardial pump failure. Using this new system, we classified the mechanism of 106 definite cardiac deaths from the Recurrent Coronary Prevention Project. Fifty deaths (47%) were classified as arrhythmic, 46 (43%) as ischemic, and 9 (8%) as due to myocardial pump failure (1 death was not classifiable). All 36 witnessed arrhythmic deaths were sudden and 8 of 9 witnessed myocardial pump failure deaths were nonsudden. The 38 witnessed ischemic deaths were split evenly between sudden and nonsudden. Interrater agreement for the classification of mechanism was 100%. This classification scheme, if validated in subsequent studies, will provide a useful algorithm for classifying deaths by underlying mechanism.