Nonreentrant atrioventricular nodal tachycardia: The great simulator.

We present the case of a healthy 12-year-old boy without structural heart disease who was followed for several years for an arrhythmia with diverse and incorrect initial diagnoses, refractory to flecainide, metoprolol and verapamil. Thorough reevaluation of the electrocardiographic recordings led to a presumptive diagnosis of a non-reentrant atrioventricular nodal tachycardia, subsequently confirmed with electrophysiology study. Radiofrequency ablation was performed during the procedure and the arrhythmia resolved.

Atrial fibrillation and renin-angiotensin system.

Atrial Fibrillation (AF) is one of the most frequent arrhythmias, especially in elderly patients. Cardiac overload increases the incidence of AF. Clinical presentation of atrial fibrillation can occur as nonsustained paroxysms, persistent episodes and in chronic-permanent form.