A 66-year-old male patient suffers from coronary heart disease (CHD) and atherosclerosis. During stomatological treatment the patient complained about acute retrosternal pain with irradiation to the left scapula, that was accompanied by stupor of the left hand. Objectively: the skin was pale, the sweat stood out on his forehead. The arterial pressure was 140/90 mm Hg, pulse was rhythmic 75 bpm. The pain wasn't relieved by Validol but it started to abate after nitroglycerin intake. What disease provoked the attack in this patient?