Thirty patients with severe symptomatic coronary artery disease were studied with two 48-h periods of ambulatory ST Holter monitoring. In common with other groups, there was a much higher incidence of asymptomatic (341 or 66.2 per cent) than symptomatic (174 or 33.8 per cent) ST segment depressions. Seventy-eight (15.1 per cent) of the ST segment depressions occurring in the absence of angina pain (and hence termed asymptomatic) were actually associated with other somatic sensations such as breathlessness and emotional upset. Reported disorders of sleep and poor energy levels were also associated with more ischaemic events. The view is presented that it is no longer adequate to obtain a classical history of angina pectoris for this poorly reflects the ischaemic myocardium. It is the functional capacity of the pump rather than the appearance of the rigid narrowings of the coronary arteries that is of importance both for the patient and the left ventricle. Further the role of mental upset occurring in daily life appears increasingly important in the aetiology of silent myocardial ischaemia. Recognition of this and appropriate counselling of the patient is important.