Twenty-three patients with variant angina were studied by Holter monitoring both to assess the incidence of serious ventricular arrhythmias (a risk factor of sudden death in variant angina), during ischaemic episodes and to examine the time-relation of the arrhythmias to ST changes. Serious ventricular arrhythmias were observed in 12/23 patients (52%). In the 23 patients, a total of 491 episodes of ST segment elevation were recorded during 954 h of Holter monitoring; serious ventricular arrhythmias were found in only 46 ischaemic episodes (9.4%). Six out of 12 patients showed serious ventricular arrhythmias at the onset of ischaemic episodes or during maximal ST elevation (phase 1), one patient during return or immediately after return of ST to baseline (phase 2) and five patients during both phases. Thirty-three out of 46 ischaemic episodes (76%) showed serious ventricular arrhythmias during phase 1, eight (17%) during phase 2, and five (11%) during both phases. Serious ventricular arrhythmias were neither related to previous myocardial infarction nor to the presence of serious ventricular arrhythmias during inter-crisis periods, whereas a good relationship with severity of ischaemic episodes, as assessed by the magnitude and duration of ST elevation, was found. A modest relationship with anterior ST elevation was also found.
In conclusion: (1) serious ventricular arrhythmias occur in a high percentage of variant angina patients, but in only a small proportion of ischaemic episodes; (2) serious ventricular arrhythmias are related to the severity of ischaemia and occur predominantly at the onset of ischaemic episodes and/or during maximal ST elevation; in only a few cases do they occur during resolution of ischaemic episodes.