Arrhythmias in variant angina pectoris. Relationship of arrhythmias to ST-segment elevation and R-wave changes.

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Abstract
Patients (26) with variant angina pectoris (VAP) were studied to determine whether the degree of ST-segment elevation and R-wave changes correlate with the development of arrhythmias and to evaluate the relationship between the prevalence of arrhythmias, the severity of coronary artery disease, left ventricular function and wall motion. Serious arrhythmias were found in 12 patients (46%) (ventricular fibrillation in 2, ventricular tachycardia in 4, ventricular premature complexes [VPC] [> 5 VPC/min, multifocal and R-on-T phenomenon] in 4, and 2nd- and 3rd-degree atrioventricular block in 3). All 12 patients with arrhythmias had ST-segment elevation .gtoreq. 0.4 mV during VAP (range 0.4-1.6 mV). R-wave amplitude [%.DELTA.R] was compared before and during episodes of VAP. An increase in R .gtoreq. 10% was seen in 10 of 12 patients with arrhythmias (group 1) and in only 6 of 14 patients without arrhythmias (group 2) (P < 0.05). Of the 26 patients, 23 underwent coronary angiography and ventriculography, and one was examined by autopsy. Sixteen patients in this group had single or multiple high-grade obstructive lesions, while the remaining 8 had normal coronary arteriograms. Arrhythmias were more common in the group with coronary obstructive disease (66%) than in the group with normal coronary arteriograms (44%). There was no significant difference between patients with arrhythmias (group 1) and those without arrhythmias (group 2) in the coronary arteriographic score or left ventricular ejection fraction. Arrhythmias apparently occur frequently during VAP and correlate well with the degree of ST-segment elevation and %.DELTA.R. In patients with VAP, arrhythmias are not contingent upon preexisting coronary artery disease or left ventricular ejection fraction, and are more commonly detected in patients with normal coronary arteriograms.