Quality of life is as impaired in patients with intermittent AF as in patients with significant structural heart disease. Patients' perception of QoL is not dependent on the objective measures of disease severity that are usually employed.

Transvenous catheter cryoablation is an effective method to create PV electrical isolation for the treatment of AF. A clinically satisfactory result can be achieved in 71% of patients with AF, without the risk of PV stenosis.

This novel cryoablation system appears to be safe and can successfully treat different types of SVTs, including AF. Isolation of PVs is possible without producing stenosis. Despite the high blood flow in the right atrial isthmus and PVs, bidirectional conduction block can be achieved.

Background-Radiofrequency ablation (RF) of atrial flutter (AFL) has a high procedural efficacy, a low recurrence rate, and reports of procedure-related pain. The aim of the present study was to compare RF with cryoablation (cryo) for the treatment of AFL, with emphasis on pain perception during application of energy. Methods and Results-Fourteen patients (55Ϯ11 years, 11 males) with AFL were randomized to receive ablation of the cavotricuspid isthmus (CTI) by either RF or cryo. Cryothermia was delivered with the CryoCor Cryoablation System (10F, 6-mm tip), and radiofrequency energy was delivered with the use of an 8-mm-tip catheter. Pain was evaluated according to a visual analogue scale (VAS; 0 to 100). All patients in the cryo group were successfully ablated with a mean of 18 applications (9 sites), and RF was successful in 6 of 7 patients (not significant) with 13 applications (not significant). The mean temperature was Ϫ82°C and 55°C for cryo and RF, respectively. One patient in the cryo group perceived pain, versus all 7 patients in the RF group (PϽ0.05). The proportion of painful applications averaged 75.3% in the RF group and 2.0% in the cryo group (PϽ0.05), whereas the corresponding VAS for pain was 38.3Ϯ25.3 and 0.32Ϯ0.86, respectively (PϽ0.05). At 6-month follow-up, there were no recurrences of atrial flutter. Conclusion-Cryo, as compared with RF, produces significantly less pain during application. Although in the present study there was no significant difference in efficacy, larger studies will be needed to definitively compare efficacy.

Objectives-To study the incidence and mode of onset of early reinitiation of atrial fibrillation (ERAF) following successful internal cardioversion of chronic atrial fibrillation, and to determine the eVects of sotalol in the prevention of ERAF. Design-The incidence and modes of onset of ERAF and the acute eVects of intravenous sotalol in the prevention of ERAF were studied retrospectively. Setting-Electrophysiology laboratory at a university teaching hospital. Patients-64 patients, mean (SD) age 62 (10) years, who underwent internal cardioversion of chronic atrial fibrillation (mean duration of atrial fibrillation 31 (39) months). Main outcome measures-ECGs and intracardiac electrograms recorded during the internal cardioversion of atrial fibrillation using 3/3 ms biphasic, R wave synchronised shocks. Results-52 patients (81%) had successful electrical cardioversion, and 20 (31%) of these had ERAF during the procedure. There was no clinical predictor for the occurrence of ERAF. Fifty eight episodes of ERAF were observed. Five ERAF episodes (9%) had preceding bradycardia and 53 (91%) of these were triggered by atrial premature beats with normal preceding heart rate. Atrial premature beats that reinitiated atrial fibrillation had a shorter coupling interval (333 (43) ms v 396 (100), p < 0.001) and a lower prematurity index (0.44 (0.11) v 0.55 (0.14), p < 0.001) than those that did not reinitiate atrial fibrillation. Repeated shock delivery and increasing the defibrillation energy did not prevent ERAF. Intravenous sotalol infusion decreased the numbers of atrial premature beats and prolonged their coupling interval, and prevented ERAF after repeated defibrillation in 83% of patients with ERAF. Conclusions-ERAF is a significant clinical problem after successful internal cardioversion of chronic atrial fibrillation, and was observed in up to 31% of patients. In most episodes, ERAF was triggered by short coupling atrial premature beats with preceding normal heart rate. Intravenous sotalol was eVective in preventing ERAF in most cases. (Heart 1999;82:319-324)