Disaster and cardiac disease.

Evidence obtained over the past decade has revealed that cardiac events and sudden cardiac deaths do not occur randomly but are caused by daily activities and emotional stress. Important triggers may be stress on autonomic nervous tone and sympathetic activities. Such sympathetic activities are changed in a circadian manner with fluctuations in blood rheology and catecholamine secretion. The threshold of electrical instability, left ventricular dysfunction and coronary stenosis may become reduced through the acceleration of sympathetic tone due to emotional stress, thus causing malignant arrhythmia and plaque rupture. Recognition of this multifactorial pathophysiology provides a basis for understanding preventive strategies.