The multicentre observational study POL-CA involves a wide spectrum of patients with a history of syncopy. The study recruits patients with diagnosed vasovagal syndrome, cardioinhibitory carotid sinus syndrome, symptomatic sinus bradycardia or atrioventricular block, postural orthostatic tachycardia syndrome, orthostatic hypotension, and inappropriate sinus tachycardia syndrome. This is an observational, controlled study with retrospective, clinical data analysis of previously treated patients and the analysis of syncopal patients prospectively recruited into the study. The aim of the POL-CA registry is to create a platform for physicians to record treatment data for patients undergoing procedures that affect innervation or modify cardiovascular reflexes (cardioneuroablation, cardioneuromodulation) in order to provide a multicentre summary of population characteristics and treatment outcomes based on a standardized POL-CA questionnaire and methodology for various arrhythmias.