Factors influencing the presence or absence of acute coronary artery thrombi in sudden ischaemic death

Sudden ischaemic death results either from an episode of acutemyocardial ischaemia consequent upon coronary thrombosis orfrom an arrhythmia arising within a scarred left ventricle.Very different proportions of these two groups have been reportedin both clinical studies in resuscitated subjects with out-of-hospitalventricular fibrillation, and in necropsy series. In 168 casesof sudden death due to ischaemic heart disease coming to necropsy73(43.5%) had mural intraluminal coronary thrombi, 50(29.8%)had occlusive intra-luminal thrombi, and 45(26.7%) had no intraluminalthrombi, giving a ratio of 2.7:1 for those with and withoutcoronary thrombosis. Single vessel disease, the presence ofacute infarction at autopsy and prodromal symptoms were positivelyassociated with the presence of coronary thrombosis. Conversely,the presence of old myocardial infarction at necropsy, a knownclinical history of ischaemic heart disease and triple vesseldisease were associated with the absence of acute thrombosis.The reported variation in the incidence of coronary thrombiin sudden ischaemic death can be largely explained by selectionof subjects with those clinical characteristics which are positivelyor negatively associated with coronary thrombosis.