Cardioneuroablation (CNA) is a new promising method to treat reflex syncope which is due to vagally-induced functional sinus arrest or atrio-ventricular block (AVB). Although the procedure is effective in \> 80% of patients, there are potential adverse effects associated with the lack of vagal protection. One of them is increased sinus rate and possible worsening of exercise capacity. However, it is not known how often this happens. Moreover, the most accurate tool to asses exercise capacity - cardiopulmonary exercise testing (CPET), has not yet been used in this group of patients. Therefore, the aim of the study is to assess one-year effects of CNA-induced total vagal denervation on cardiorespiratory fitness in patients undergoing CNA due to reflex asystolic syncope. The study group consists of patients undergoing CNA in our institution. All patients give informed written consent to undergo CNA and to participate in the study (Ethics Committee approval # 22/2024). CNA is performed according to standard protocol used in our institution. A symptom-limited cardiopulmonary exercise (CPET) is performed twice, at baseline (1-2 days before CNA) and after one year of follow-up. Standard CPET parameters are measured. Quality of life is measured using a dedicated questionnaire. Also, a control group of healthy volunteers will undergo CPET to answer the question whether subjects with reflex syncope differ in exercise capacity from healthy people.