Bradycardia-tachycardia syndrome is characterized by alternating episodes of supraventricular tachycardia (atrial tachycardia, AF, common flutter) and episodes of bradycardia in conjunction with a sinus dysfunction. Symptomatology combines secondary clinical signs with tachycardia (palpitations, heart failure) and bradycardia (fatigue, cognitive disorders, dyspnea, lipothymia, syncope). This association suggests the presence of diffuse atrial organic lesions with degenerative impairment of sinus node automatic cells but also fibrosis extending to the atrial myocardium and sometimes to the specific tissue of the atrioventricular junction explaining the possible concomitant observation of atrioventricular conduction disorders. It is common to differentiate bradycardia-tachycardia syndrome (absence of a chronological link between tachycardia and bradycardia episodes) and post-conversion pauses (sinus pauses observed exclusively during the termination of atrial arrhythmias). This patient concurrently presented symptomatic post-conversion pauses, nocturnal sinus bradycardia and pauses occurring during baseline sinus rhythm. She underwent implantation of a pacemaker which allowed preventing syncopal recurrences. The introduction of beta blocker therapy also limited the increase in heart rate of conducted AF episodes.