Background-Radiofrequency catheter ablation of atrial fibrillation (AF) guided by complex fractionated atrial electrograms has been reported to eliminate AF in a large proportion of patients. However, only a small number of patients with chronic AF have been included in previous studies. Methods and Results-In 100 patients (mean age, 57Ϯ11 years) with chronic AF, radiofrequency ablation was performed to target complex fractionated atrial electrograms at the pulmonary vein ostial and antral areas, various regions of the left atrium, and the coronary sinus until AF terminated or all identified complex fractionated atrial electrograms were eliminated. Ablation sites consisted of Ն1 pulmonary vein in 46% of patients; the left atrial septum, roof, or anterior wall in all; and the coronary sinus in 55%. During 14Ϯ7 months of follow-up after a single ablation procedure, 33% of patients were in sinus rhythm without antiarrhythmic drugs, 38% had AF, 17% had both AF and atrial flutter, 9% had persistent atrial flutter, and 3% had paroxysmal AF on antiarrhythmic drugs. A second ablation procedure was performed in 44% of patients. Pulmonary vein tachycardia was found in all patients in both previously targeted and nontargeted pulmonary veins. There were multiple macroreentrant circuits in the majority of patients with atrial flutter. At 13Ϯ7 months after the last ablation procedure, 57% of patients were in sinus rhythm without antiarrhythmic drugs, 32% had persistent AF, 6% had paroxysmal AF, and 5% had atrial flutter. Conclusions-Modest short-term efficacy is achievable with radiofrequency ablation of chronic AF guided by complex fractionated atrial electrograms, but only after a second ablation procedure in Ͼ40% of patients. Rapid activity in the pulmonary veins and multiple macroreentrant circuits are common mechanisms of recurrent atrial arrhythmias. (Circulation.

Isoproterenol at infusion rates up to 20 microg/min has a high sensitivity (88%) and specificity (95%) for induction of AF in patients with PAF, regardless of whether the clinical subtype is vagotonic, adrenergic, or random.

Background-With electrogram-guided radiofrequency ablation (RFA) of long-lasting persistent atrial fibrillation (AF), the best results have been reported when complex fractionated electrograms (CFAEs) in both the left (LA) and right (RA) atria were targeted. However, many studies have reported excellent outcomes from RFA of long-lasting persistent AF with the use of other ablation strategies that were limited to the LA. The incremental value of RFA of RA CFAEs is yet to be defined. Methods and Results-In 85 patients with long-lasting persistent AF (ageϭ59Ϯ10 years), RFA was directed at CFAEs in the LA and coronary sinus until AF terminated (19) or all identified LA CFAEs were eliminated. Sixty-six patients who remained in AF were randomly assigned to cardioversion and no further RFA (nϭ33) or to RFA of RA CFAEs (nϭ33). RA sites consisted of the crista terminalis (69%), septum (38%), superior vena cava (28%), coronary sinus ostium (22%), and the base of the appendage (31%). AF terminated in 1 (3%) of 33 patients during RA RFA. At 17Ϯ6 months after a single ablation procedure, 74% of the patients in whom AF terminated during LA RFA were in sinus rhythm. Rates of freedom from AF were similar in the patients randomized to no RFA in the RA (24%) and those randomized to RFA of RA CFAEs (30%, Pϭ0.8). The ablation procedure was repeated in 26 patients (31%) for AF (nϭ22) or atrial flutter (nϭ4). At 16Ϯ7 months after the final procedure, 89% of the patients in whom AF terminated during LA RFA were in sinus rhythm. Among the randomized patients, the proportion of patients who remained in sinus rhythm was similar in patients who did not undergo RFA of RA CFAEs (52%) and those who did (58%, Pϭ0.6). Conclusion-After RFA of CFAEs in the LA and coronary sinus, ablation of CFAEs in the RA provides little or no increment in efficacy among patients with long-lasting persistent AF. (Circ Arrhythmia Electrophysiol. 2008;1:6-13.)

Cholesterol crystals damaged the endothelium and reduced vasodilator response, potentially aggravating myocardial ischemia after interventions.

No abstract