REN and Left ventricular dilatation: Patients with AF have poor long-term ventricular rate control, and the renin-angiotensin system and sympathetic nervous system are activated, which leads to left ventricular remodeling.[11] After left ventricular remodeling, the number of functional myocardial fibers in the left ventricle decreases, which in turn causes the decline of cardiac pumping function, and eventually leads to left ventricular dilatation and configuration changes.