A clinically significant case is reported, as it is the first to be published in the region. It refers to a patient who was admitted to the hospital through the emergency department after four days ofillness. The initial clinical presentation included lower limb edema and functional class II dyspnea, which progressed to class IV. A 12-lead electrocardiogram showed atrial tachycardia with a heart rate of 187 bpm. Sequential administration of adenosine, verapamil and electrical cardioversion was unsuccessful. Subsequently, amiodarone was given, leading to the restoration of sinus rhythm. On the second day of hospitalization, the patient developed frequent ventricular ectopic beats and episodes of supraventricular ectopic beats, for which amiodarone was continued. On the third day, he presented with an increased frequency of ventricular ectopy and non-sustained ventricular tachycardia, whic...