Clinical significance of daily work angina and its relation to unstable angina

The incidence of angina pectoris was studied in 247 patients having a long history of this disorder. Angina of effort (EA), angina at rest (RA) and daily work angina (DA) occurred in 91, 57 and 29% of these cases, respectively. Sixty-three percent of the cases had histories of more than 2 types of angina, EA, RA and DA. DA occurred in 39, 25 and 27% of the cases with new EA, new RA and changing pattern of unstable angina (UA), respectively, and it occurred coincidentally with the period of UA. Therefore, DA was considered as a pattern of UA. UA could not be classified well according to the precipitating factors or spontaneous occurrence and its classification according to a new occurrence or worsening condition is clinically useful for predicting a short-term prognosis. Ischemic ST changes seemed to be preceded by an increase of heart rate and blood pressure in micturition angina, although these increases were significantly lower than those in exercise-induced angina. Beta-blocking agents were ineffective but calcium antagonists were effective for micturition angina. Voiding is not essential for provoking angina, since strain alone could induce angina. Common pathophysiological status, such as coronary arterial spasm, may underlie all types of DA.