CLINICAL STUDY OF VARIANT FORM OF ANGINA PECTORIS

抄録

Twenty eight cases of variant form of angina pectoris, included 27 males and 1 female were studied during a 10 years period. The age of onset of symptoms were 44 to 73 years old with average of 58. 1. Onset of angina usually occurred during rest at night, 25 out of 28 patients were attacked between 1 : 00 AM to 8 : 00 AM. Usually, the attack was in cyclic fashion, 4 to 15 episodes and each episode lasts for 2 to 10 minutes in duration. 2. As the anginal pain is over, the patient remain well and free of pain in rest at night and day time. 3. There was no significant variation of blood pressure between attack and after anginal episodes. Eight out of 15 patients showed slightly decreased in the blood pressure during anginal pain. 4. ECG study showed that 6 patients had involvement of the left coronary; 21, the right coronary artery and 1, both arteries. 5. In 11 cases ST segment elevation could occur by two step exercise test, this is different to the preliminary report of Prinzmetal et al. 6. Arrhythmias and conductive disturbance occurred in 10 out of 28 patients (35.7%) complete A-V block with VPCs in 2, VPCs only in 5, atrial fibrillation in 2, Wenckebach type A-V block in one and RBBB in one. 7. Twenty two out of 28 patients were placed on physical training program, and thus the frequency of anginal attacks were decreased and its physical capacity reached to significantly more than before in one to two months from admission. 8. One patient had left and right coronary cineangiograms, which showed slight narrowing of anterior descending branch, poor distal run-off on left circumflex branch and stagnation of dye on apex. The right coronary artery was almost normal. 9. In the follow-up study, out of 23 patients observed from 4 months to 10 years, only 3 patients died, one due to Hodgkin's disease, one expired suddenly on 10 years later from another anginal attack. Only one patient developed into myocardial infarction on the third hospital day, and expired, autopsy was performed. In histopathological findings of the autopsy case, the left coronary artery showed intimal thickening and narrowing of the vessel lumen by about 75 % with calcification. The right coronary artery showed severe calcification and stenosis of the entire lumen. 10. Nitroglycerin or isosobide dinitrate during acute attack is much more effective, although β-blockade may play an some role to prevent and reduce the frequency of attack. 11. The effect of anticoagulant therapy can not be predicted. 12. Good exercise capacity was preserved in variant form of angina. Exercise may improve the formation of coronary collateral circulation, and normalization of unbalanced autonomic nervous system. 13. The most important coronary risk factor seems to be hypertension, however, the incidence of hypertension at admission is low. The mechanism which decreased spontaneously the blood pressure in patients with variant angina is not clear, but it is speculated that this mechanism might be responsible to play a role to produce the attack of variant angina.