(wel´enz) a group of signs indicating critical proximal stenosis of the left anterior descending coronary artery in patients with unstable angina at a time when there is no pain. It consists of normal or minimally elevated cardiac enzyme levels; little or no elevation of the ST segment; no loss of precordial R waves; and progressive, deep, symmetrical inversion of the T waves, particularly in leads V 1 and V 2 (though not confined to these leads).