[Sick sinus node syndrome ¿Pacemaker or ablation? Case report].

The tachycardia-bradycardia syndrome is the most frequent form of presentation of Sick sinus node syndrome and is commonly characterized by episodes of paroxysmal atrial fibrillation followed by significant pauses, especially in older adult patients. Other frequently associated tachyarrhythmias are atrial tachycardia and atrial flutter. The association between orthodromic tachycardia and significant pauses in these patients is an unusual presentation. We present the case of an older adult with bradycardia-tachycardia syndrome and syncope, who presented with a hidden accessory pathway and who, after successful ablation of it, did not present syncope again.