In patients with variant angina, ST-segment elevations predominantly occurred early morning (72% between 0:00 and 9:00) and were mostly asymptomatic (79%), with arrhythmias common during reperfusion.
Observational (n=26)
In patients with variant angina, asymptomatic coronary artery spasms predominantly occur early in the morning, and complex arrhythmias can appear during both symptomatic and asymptomatic episodes, particularly during the reperfusion phase.
Twenty-four-hour ambulatory ECG recording was performed in 26 patients with variant angina to evaluate the diurnal distribution of ST-segment elevation in relation to chest pain and the incidence of arrhythmias during the episodes. During a recording period of 52 days, 364 ST-segment elevations of 1 mm or greater were observed and 79% were asymptomatic. ST-segment elevation frequently occurred between 0:00 and 9:00 hours (72%) and most frequently between 5:00 and 6:00 hours (13%). Only a few episodes occurred between 10:00 and 18:00 hours. Premature atrial contractions, premature ventricular contractions (PVCs), ventricular tachycardia (VT) and complete atrioventricular block occurred during 12% of the episodes and were more common during painful episodes (32%) than during painless ones (6%). However, VT and severe forms of PVCs (couplets and bigeminy) appeared eight times during painless episodes and nine times during painful ones. Arrhythmias occurred more frequently when the elevated ST segment started to return or was returning to the control level (n = 38) than when the ST segment was rising (n = 8). The incidence of arrhythmias was lower when the daily frequency of ischemic episodes was high. This study shows that episodes of asymptomatic coronary artery spasm predominantly occur early in the morning as symptomatic episodes; complex dysrhythmias appear during the asymptomatic episodes; arrhythmias occur predominantly during a "reperfusion period;" and more arrhythmias accompany infrequent daily episodes of ischemia than frequent ones.
Araki et al. (Sun,) conducted a observational in variant angina (n=26). ST-segment elevation episodes was evaluated on Diurnal distribution of ST-segment elevation and incidence of arrhythmias. In patients with variant angina, ST-segment elevations predominantly occurred early morning (72% between 0:00 and 9:00) and were mostly asymptomatic (79%), with arrhythmias common during reperfusion.