Case For Ecg...1

Case A 74-year-old woman was admitted our hospital due to several episodes of dizziness and syncope. Her past medical history was not remarkable. Physical examination revealed no abnormalities except irregular and rapid heart beats. The 12-lead ECG on admission showed a rapid and irregularly irregular rhythm followed by loss of electrical activity which occupy the last one-third of the recoding (Fig. 1). Rhythm strip recording on ward revealed repeated paroxysms of the same tachyarrhythmia followed by ventricular asystole ranging 5 to 12 seconds (Fig. 2). The patient told us she felt dizziness at the time of long ventricular asystole. She was started on oral flecainide (200 mg/day) to suppress the attacks of the tachyarrhythmia with a hope that it may prevent ventricular asystole because every witnessed episodes of ventricular asystole developed after spontaneous termination of the tachycardia. After restoring sinus rhythm sinus pause developed intermittently (Fig 3). Therefore we thought she needed a permanent pacemaker. Sinus node and AV conduction system were evaluated with electrophysiology study. Sinus node function was remarkably depressed; SNRT, 5,063 ms, corrected SNRT 3,035 ms. There was no significant change in the values after IV administration of atropine (2.0 mg). AV block cycle length was 490 ms and no VA conduction was present. Finally, we put a VVI pacemaker. She was discharged on oral flecainide (150 mg/day) with no events on the 10th hospital day. Her final diagnosis was sick sinus syndrome presenting with bradycardia-tachycardia syndrome requiring antiarrhythmic drug therapy and permanent pacemaker implantation to control paroxysmal atrial fibrillation and to prevent long ventricular asystole.

Legend Fig. 1. A 12-lead electrocardiogram (ECG) showing a rapid irregularly irregular rhythm followed by total loss of electrical signal.

Fig. 2. Rhythm strip recording of ECG revealing that paroxysmal attacks of atrial fibrillation always terminated with a long ventricular asystole.

Fig. 3. Sinus pause recorded after restoring sinus rhythm with oral flecainide.

Fig. 4. A 12-lead ECG recorded after implanting a permanent VVI pacemaker.