Patient W., 60 years old. Complaints of a feeling of lack of air, interruptions in the work of the heart, weakness, dizziness. Heart rate 152 per minute, heart rate 130 per minute, heart rate deficiency 22. When recording an ECG, the following was revealed: 1) the absence of a P wave, instead of which f waves are recorded; 2) arrhythmic contraction of the ventricles, intervals RR ≠ RR; 3) QRS complexes of the usual form; 4) the frequency of the ventricular rhythm is 152 per minute. Questions: 1. What is a heart rhythm disorder recorded on the ECG? 2. List the forms of this rhythm disturbance. 3. Indicate the possible causes of this pathology