Right atrial compartmentalization using radiofrequency catheter ablation for management of patients with refractory atrial fibrillation.

INTRODUCTION: Atrial fibrillation (AF) is often refractory to antiarrhythmic drugs, and patients who are intolerant of AF may require the maze operation for cure. As a less invasive alternative, a catheter-based, right atrial compartmentalization procedure was evaluated. METHODS AND RESULTS: Twelve patients with AF refractory to Class I and III antiarrhythmic drugs were studied. Four linear right atrial radiofrequency ablations were performed, from superior to inferior vena cava in the posterior wall and interatrial septum, anteriorly from the superior vena cava to the tricuspid annulus through the appendage, and across the tricuspid valve-inferior vena cava isthmus. The radiofrequency catheter was dragged along each line three to four times, until the atrial electrogram amplitude decreased by 75% and there was bidirectional conduction block in the tricuspid valve-inferior vena cava isthmus. One complication occurred: sinus node dysfunction requiring a pacemaker. Eight patients were discharged from the hospital on no antiarrhythmic drugs, and four were discharged on previously ineffective antiarrhythmic drugs. Total duration of follow-up was 21.3 +/- 11.2 months. Four patients discharged on previously ineffective antiarrhythmic drugs had no recurrence of AF. One patient discharged off antiarrhythmic drugs had no recurrence of AF. Seven patients discharged off antiarrhythmic drugs had recurrent AF by 12.6 +/- 13.0 months (median 6, range 1 to 39); 3 of these 7 responded to previously ineffective antiarrhythmic drugs without further AF and 4 did not. Thus, 8 of 12 patients (67%) had suppression of AF after ablation on previously ineffective medication or no medication. CONCLUSION: Right atrial compartmentalization may alter the substrate for AF, thus improving the efficacy of previously ineffective antiarrhythmic drugs. Because it is relatively safe, it may be a reasonable adjunctive intervention to maintain sinus rhythm in patients with drug-refractory AF.

Familial sudden cardiac death associated with a terminal QRS abnormality on surface 12-lead electrocardiogram in the index case.

A case is presented of an 18-year-old male who had been resuscitated following an episode of sudden death due to ventricular fibrillation. The patient was noted to have an abnormal deflection in the terminal QRS on surface ECG and an abnormal signal-averaged ECG demonstrating a late potential coincident with the terminal QRS abnormality on the ECG. The patient had easily inducible polymorphic ventricular tachycardia during electrophysiologic study, which was suppressed by quinidine but not by procainamide or beta blockers. The surface ECG and signal-averaged ECG also were normalized by quinidine but not by procainamide or beta blockers. The patient had no further arrhythmias on quinidine for 6 years until he inexplicably discontinued his medication and died suddenly shortly thereafter. The present case may represent a unique familial sudden death syndrome or possibly a variant of the sudden death syndrome associated with right bundle branch block and ST elevation in V1 through V3. Currently available data suggest that, in such patients, an implantable cardioverter defibrillator may provide better protection from sudden death than does antiarrhythmic drug therapy.