To evaluate the association between left ventricular false tendon (LVFT) and ventricular arrhythmias in acute myocardial infarction (MI) on the 1-st day of acute MI 71 patients were examined by 24-hour ECG-monitoring and M-mode, two-dimensional, Doppler echocardiography. LVFT was detected in 30 patients (42.3%). The frequency of left ventricular fibrillation, the number of patients with multiform ectopic ventricular beats (EVB), the number of single and pair EVB and runs of ventricular tachycardia were greater in group of patients with LVFT. 37 patients had Lown grades 1-2 (A) of arrhythmias, 34 patients had grades 3-5 (B). LVFT was revealed in four patients in group A (10.8%) and in 27 patients in group B (76.5%, p < 0.001). There were no significant differences between groups in left ventricular asynergy area and wall motion score, left and right ventricular, left atrium dimensions, left ventricular contractility indices, left ventricular walls thickness, frequency of mitral regurgitation. Multifactor analysis has shown significant relationship between Lown's class value and LVFT (p < 0.0001), Lown's class and arterial hypertension (p = 0.0376). Other 17 clinical factors were not connected with Lown's class value. Thus, LVFT was associated with severe ventricular arrhythmias in patients with AMI. This fact can be used as a predictor of these disturbances.