Abstract
The long-term electrocardiograms of 58 cases of variant angina pectoris were evaluated for the cyclic changes of ST segment elevation. Among them, 31 cases (53%) showed repetitive elevations of ST segment on long-term electrocardiograms. The cycles of repetition of ST elevations were between 2 and 44, with a mean of 7. l. The large number of cycle intervals (89%) were exhibited between 6 and 20 minutes (12.2±5.0, mean±SD). The appearance times of cyclic ST elevation were 234 hours in total, and were observed from midnight to early morning in many occasions. Sixty-nine percent of them were recorded during the 8 hours between 0:00 a.m. and 8:00 a.m. (P<0. 01). The frequency of variant anginal attacks had a good correlation with that of cyclic ST elevation.
From 0:00 a.m. to 8:00 a.m., the mean frequency of attacks was 7.5 episodes per hour which was significantly high, compared with that of the other time (2.1 episodes/hr, P<0.01).The variant form of angina pectoris is strongly suggested when cyclic ST changes are recorded on the long-term electrocardiogram even without anginal attacks. The cyclic ST elevations tend to disappear along with the alleviation of variant anginal attacks by the use of antianginal drugs. We further discussed the clinical significance of the repetitive ST elevations on the long-term electrocardiograms.
