Unheralded sudden cardiac death: do autonomic tone and thrombosis interact as key factors in aetiology?

Unheralded sudden cardiac death is a personal and family tragedy that continues to elude research-based progress on aetiology or prevention. Instinctive links between autonomic imbalance, sympathetic activation and serious arrhythmia are longstanding and backed by many observational reports. However the role of the more familiar mechanisms of coronary occlusion and thrombus formation are underplayed. Sympathetic overactivity may also mediate sudden death through precipitation of vasospasm; platelet activation and inhibition of endogenous fibrinolysis as well as the propagation of arrhythmia. The integration of autonomic, thrombotic and vascular tone may be the key to better understanding of the individual process of unheralded sudden cardiac death. In this review we analyse the evidence for this hypothesis.