Transvenous Cryoablation of Cardiac Arrhythmias

Ten-year follow-up after endocardial point-by-point cryoablation for paroxysmal atrial fibrillation

BACKGROUND

Since many years catheter ablation is widely used for the treatment of atrial fibrillation (AF), however, long-term follow-up data of ablation techniques are rare. This study presents a 10-year follow-up period in patients treated for paroxysmal AF (PAF) with point-by-point pulmonary vein isolation (PVI) using cryothermal energy (cryoPVI). The main objective is to investigate whether cryoPVI is able to create durable PVI.

METHODS

All consecutive patients with PAF who underwent a point-by-point cryoPVI were included. Information from the index procedure, anti-arrhythmic drug (AAD) use, recurrence of arrhythmias and re-ablation, was retrospectively analysed. Re-ablations were specifically evaluated for reconnection of PVs.

RESULTS

Seventy-three patients were included. Five (7%) were lost to follow-up and 55/73 (75%) reached 10-year follow-up (median follow-up duration: 11.3 years [10.0-12.4]). Thirteen (18%) did not reach 10-years follow-up (mean follow-up duration: 4.4 ± 3.3 years). All targeted PVs were successfully isolated during the index procedure. Only 10/68 patients (15%) kept sinus rhythm (SR) without the use of AAD or a re-ablation. Re-ablations were performed in 47/68 patients (69%). Reconnection was seen in 81% of the PVs.

CONCLUSIONS

Ostial point-by-point cryoPVI has the ability to provide acute electrical isolation of arrhythmogenic PVs based on abolition of all PV potentials, but fails in long-term isolation and prevention of AF-recurrence in most patients.

Current treatment options for atrial flutter and results with cryocatheter ablation

Rhythm disturbances arising in the upper chambers of the heart are not uncommon. They are associated with a heavy burden of illness for the affected individual, as well as society in general. Atrial flutter, a re-entrant atrial tachycardia, is one such rhythm disturbance. The objective of this review article is twofold: first, to provide a brief insight into atrial flutter and the typical treatments for this arrhythmia in clinical practice; and second, to give an in-depth account of cryocatheter ablation as a relatively new treatment option for this potentially debilitating condition. The many recent clinical studies documenting the use of cryocatheter ablation for treatment of atrial flutter are presented, and their results briefly discussed. Overall, as cryocatheter ablation embeds itself among the arsenal of treatments for atrial flutter, the promising results from clinical studies appear destined to elevate cryocatheter ablation to a premier position among the treatment options for atrial flutter.

Long term outcome of cavotricuspid isthmus cryoablation for the treatment of common atrial flutter in 180 patients: a single center experience

OBJECTIVE

Recent literature has shown that common type atrial flutter (AFL) can recur late after cavotricuspid isthmus (CTI) catheter ablation using radiofrequency energy (RF). We report the long term outcome of a large group of patients undergoing CTI ablation using cryothermy for AFL in a single center.

METHODS

Patients with AFL referred for CTI ablation were recruited prospectively from July 2001 to July 2006. Cryoablation was performed using a deflectable, 10.5 F, 6.5 mm tip catheter. CTI block was reassessed 30 min after the last application during isoproterenol infusion. Recurrences were evaluated by 12-lead ECG and 24 h Holter recording every clinic visit (1/3/6/9 and 12 months after the procedure and yearly thereafter) or if symptoms developed.

RESULTS

The 180 enrolled patients had the following characteristics: 39 women (22%), mean age 58 years, no structural heart disease in 86 patients (48%), mean left atrium diameter 44+/-7 mm and mean left ventricular ejection fraction 57+/-7%. The average number of applications per patient was 7 (3 to 20) with a mean temperature and duration of -88 degrees C and 3 min, respectively. Acute success was achieved in 95% (171) of the patients. There were no complications. After a mean follow-up of 27+/-17 (from 12 to 60) months, the chronic success rate was 91%. The majority of the recurrences occurred within the first year post ablation. One hundred and twenty three patients had a history of atrial fibrillation (AF) prior to CTI ablation and 85 (69%) of those remained having AF after cryoablation. In 20 of 57 (35%) patients without a history of AF prior to CTI ablation, AF occurred during follow-up.

CONCLUSIONS

This prospective study showed a 91% chronic success rate (range 12 to 60 months) for cryoablation of the CTI in patients with common type AFL and ratified the frequent association of AF with AFL.

Atrial flutter: a focus on treatment options for a common supraventricular tachyarrhythmia

Atrial flutter (AFl), a re-entrant atrial tachycardia, is a cardiac rhythm disturbance that arises in the upper chambers of the heart. This usually non-life-threatening condition can be treated by a number of medical intervention strategies, which include electrical cardioversion, pharmacological therapy, and catheter ablation. These options have been available in clinical practice for a number of years. However, catheter ablation, in the form of radiofrequency catheter ablation and cryo catheter ablation, is increasingly utilised as a first-line treatment option for AFl in certain patients. The purpose of this review article is two-fold: first, to briefly present an overview of AFl and the more familiar treatment options for this arrhythmia, and second to provide more in-depth coverage of catheter ablation technologies as a treatment option for patients with AFl. As part of the latter objective, recent clinical studies documenting the use of radiofrequency catheter ablation and cryo catheter ablation for AFl are presented and their results briefly discussed.