Lack of impact of prevention on sudden cardiac death

There are many different and relatively discrete mechanisms leading to ventricular fibrillation. Therefore, any single approach to prevention is likely to be unsuccessful, particularly because the circumstances that finally cause sudden cardiac death may not be present for more than a short time before the onset of ventricular fibrillation. It should not be surprising, therefore, that neither primary nor secondary prevention trials directed at correcting risk factors for coronary heart disease have been associated with a reduction in the incidence of sudden cardiac death. More trials are needed in patients with unstable angina, in whom there is a relatively high incidence of sudden cardiac death within a short period. Methods of modulating catecholamine response, myocardial vulnerability and thrombotic mechanisms require more formal testing. However, because the sensitivity and specificity of prediction of those likely to die suddenly are so poor, it may become necessary to accept that the majority of sudden cardiac deaths is not yet preventable and focus on continuing to improve cardiopulmonary resuscitation services