Ischemic changes on electrocardiography and on diameter of coronary artery.

(A) Ischemic changes on electrocardiography before and during angina attack. During the attack, ST level was depressed significantly in the chest leads from V2 to V6. (B) Changes of diameter of coronary artery before and after intracoronary injection (IC) of isosorbide dinitrate (NTG). Coronary arteries were spastic without any significant organic lesions and widened more than twice the width of controls shortly after intracoronary injection of isosorbide dinitrate.