[A case of atrial paralysis during the use of intravenous flecainide acetate]

The aim of the present study is to describe a case of complete temporary atrial standstill, following iv administration of flecainide during the course of an endocavitary electrophysiologic study (EES). The patient, 79 years old, with frequent anamnestic periods of flutter and atrial fibrillation, which was followed by heart failure and with conductory disturbances to the surface ECG (first degree A-V block and left axis deviation), underwent EES in order to evaluate the functional reserve of cardiac eccito-conduction. With electric programmed stimulation, during EES, we induced atrial flutter, with a cycle length of about 300 ms. The administration of flecainide, dosage 1.5 mg/Kg in 15 min, determined the complete disappearance of every atrial electric activity, confirmed by right and left (coronary sinus) atrial mapping, also after electrical stimulation, and the emergency of substitutional ventricular rhythm, to a frequency of about 30-40/min. After atropine, dosage 0.02 mg/Kg iv, we noted an increase in the frequency of added focus up to the value of about 110 b/min, without any evidence of atrial electric activity. With sulfate isoprenaline in venous infusion, dosing 2 gamma/min, we noted firstly a ventricular-atrial back-leading 1:1; and after an ectopic atrial rhythm, with a frequency of about 130 b/min. After 5 hours a sinusal rhythm appeared.