A 65-year-old woman with overweight suddenly developed an attack of pressing pain in the chest, mainly behind the sternum, radiating to both shoulders, aggravated by physical exertion lasting for 2 hours. Heart auscultation: soft sounds, rhythmic. Pulse is 92 bpm, satisfactory filling and tension; BP is 160/90 mm Hg. What is your diagnostic assumption? A.Intercostal neuralgia B.Myocardial infarction C.Angina pectoris D.Osteochondrosis