SUMMARY Twenty-six patients with variant angina pectoris (VAP) were studied 1) to determine whether the degree of ST-segment elevation and R-wave changes correlate with the development of arrhythmias; and 2) 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 two, ventricular tachycardia in four, ventricular premature complexes [VPCs] [> 5 VPCs/min, multifocal and R-on-T phenomenon] in four, and second-and third-degree atrioventricular block in three). All twelve patients with arrhythmias had ST-segment elevation > 0.4 mV during VAP (range 0.4-1.6 mV). R-wave amplitude was compared before and during episodes of VAP and expressed as %AR. An increase in R 10% was seen in 10 of 12 patients with arrhythmias (group 1) and in only six of 14 patients without arrhythmias (group 2) (p < 0.05).Twenty-three of the 26 patients 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 eight 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 I) and those without arrhythmias (group 2) in the coronary arteriographic score or left ventricular ejection fraction.The data suggest that arrhythmias occur frequently during VAP and correlate well with the degree of STsegment elevation and %AR. 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. IN 1959 and1960, Prinzmetal et al.' 2 delineated a variant form of angina pectoris (VAP) that primarily differs from Heberden's classic angina pectoris in that the pain is frequently spontaneous, occurs at rest, and is unrelated to physical activity or emotion. The pain in VAP generally lasts longer and may be more severe than in classic angina pectoris. Attacks tend to be cyclic, often recurring at a specific time of day. Episodes of pain are accompanied by transient STsegment elevation with reciprocal changes in the standard leads, as opposed to typical ST-segment depression. VAP has been reported3-7 in patients with normal coronary arteriograms,1 2, 8 as well as in those with angiographically demonstrated focal lesions that affect the proximal segment of the coronary arteries.Abnormalities of rhythm and conduction may be associated with VAP.6 16 During pain, the wide spectrum of reported arrhythmias includes second-and third-degree atrioventricular block,6' 7, 9, 10 ventricular tachycardia and ventricular fibrillation,10' 11 ventricular premature complexes (VPCs),13' 14 ventricular asystole'5 and atrial fibrillation. 16 We studied ...