This scientific work evaluates the clinical and instrumental features of the course of myocardial infarction during paroxysmal AF, thanks to the combined use of methods for assessing troponin I, ECG, coronary angiography (CAG), and transthoracic echocardiography. The study included 128 patients hospitalized in emergency care departments No. 1 and 2, and cardiac intensive care unit of the Samarkand branch of the Republican Scientific Center for Emergency Medical Care. Paroxysmal AF may develop against the background of a more serious pathology, such as atherosclerotic lesions of the coronary arteries or lead to secondary myocardial damage. Studying troponin levels in this group of patients seems justified.