Recurrent atrial flutter and atrial fibrillation after catheter ablation of the cavotricuspid isthmus: a very long-term follow-up of 333 patients

Incidence and patterns of atrial fibrillation after catheter ablation of typical atrial flutter-the FLUTFIB study

AIMS

In patients with atrial flutter (AFL), ablation of the cavotricuspid isthmus (CTI) is a highly effective procedure to prevent AFL recurrence, but atrial fibrillation (AF) may occur during follow-up. The presented FLUTFIB study was designed to identify the exact incidence, duration, timely occurrence, and associated symptoms of AF after CTI ablation using continuous cardiac monitoring via implantable loop recorders.

METHODS AND RESULTS

One hundred patients with AFL without prior AF diagnosis were included after CTI ablation (mean age 69.7 ± 9.7 years, 18% female) and received an implantable loop recorder for AF detection. After a median follow-up of 24 months 77 patients (77%) were diagnosed with AF episodes. Median time to first AF occurrence was 180 (43-298) days. Episodes lasted longer than 1 h in most patients (45/77, 58%). Forty patients (52%) had AF-associated symptoms.Patients with and without AF development showed similar baseline characteristics and neither HATCH- nor CHA2DS2-VASc scores were predictive of future AF episodes. Oral anticoagulation (OAC) was stopped during FU in 32 patients (32%) and was re-initiated after AF detection in 15 patients (15%). No strokes or transient ischaemic attack episodes were observed during follow-up.

CONCLUSION

This study represents the largest investigation using implantable loop recorders (ILRs) to detect AF after AFL ablation and shows a high incidence of AF episodes, most of them being asymptomatic and lasting longer than 1 h. In anticipation of trials determining the duration of AF episodes that should trigger OAC initiation, these results will help to guide anticoagulation management after CTI ablation.

Prediction of Recurrent Atrial Tachyarrhythmia After Receiving Atrial Flutter Ablation in Patients With Prior Cardiac Surgery for Valvular Heart Disease

Background: Surgical scars cause an intra-atrial conduction delay and anatomical obstacles that facilitate the perpetuation of atrial flutter (AFL). This study aimed to investigate the outcome and predictor of recurrent atrial tachyarrhythmia after catheter ablation in patients with prior cardiac surgery for valvular heart disease (VHD) who presented with AFL.

Methods: Seventy-two patients with prior cardiac surgery for VHD who underwent AFL ablation were included. The patients were categorized into a typical AFL group (n = 45) and an atypical AFL group (n = 27). The endpoint was the recurrence of atrial tachyarrhythmia during follow-up. A multivariate analysis was performed to determine the predictor of recurrence.

Results: No significant difference was found in the recurrence rate of atrial tachyarrhythmia between the two groups. Patients with concomitant atrial fibrillation (AF) had a higher recurrence of typical AFL compared with those without AF (13 vs. 0%, P = 0.012). In subgroup analysis, typical AFL patients with concomitant AF had a higher incidence of recurrent atrial tachyarrhythmia than those without it (53 vs. 14%, P = 0.006). Regarding patients without AF, the typical AFL group had a lower recurrence rate of atrial tachyarrhythmia than the atypical AFL group (14 vs. 40%, P = 0.043). Multivariate analysis showed that chronic kidney disease (CKD) and left atrial diameter (LAD) were independent predictors of recurrence.

Conclusions: In our study cohort, concomitant AF was associated with recurrence of atrial tachyarrhythmia. CKD and LAD independently predicted recurrence after AFL ablation in patients who have undergone cardiac surgery for VHD.

Preventing atrial fibrillation by combined right isthmus ablation and cryoballoon pulmonary vein isolation in patients with typical atrial flutter: PAF-CRIOBLAF study

BACKGROUND

Although less common, typical atrial flutter shares similar pathophysiological roots with atrial fibrillation. Following successful cavo-tricuspid isthmus ablation using radiofrequency, many patients, however, develop atrial fibrillation in the mid-to-long-term. This study sought to assess whether pulmonary vein isolation conducted at the same time as cavo-tricuspid isthmus ablation would significantly modify the atrial fibrillation burden upon follow-up in patients suffering from typical atrial flutter.

METHODS

This was a multicenter randomized controlled study involving typical atrial flutter patients with history of non-predominant atrial fibrillation (1 atrial fibrillation episode only, in 67% of population) who were scheduled for cavo-tricuspid isthmus radiofrequency ablation. Patients were randomly assigned to either undergo cavo-tricuspid isthmus ablation alone or cavo-tricuspid isthmus plus pulmonary vein isolation (CTI+). Pulmonary vein isolation was performed using cryoballoon technology. An outpatient consultation with ECG and 1-week Holter monitoring was performed at 3, 6 months, 1 year, and 2 years postprocedure. The primary endpoint was atrial fibrillation recurrences lasting more than 30 s at 2 years postablation.

RESULTS

Of the patients enrolled, 36 were included in each group. At 2-year follow-up, the atrial fibrillation recurrence rate was significantly higher in the CTI vs CTI+group (25/36, 69% vs. 12/36, 33% respectively; P < .001), with similar typical atrial flutter recurrence rates. There were no differences in undesirable events, except for transient phrenic nerve palsy reported from three CTI+patients (8.3%).

CONCLUSION

Pulmonary vein isolation using cryoballoon technology was proven to significantly reduce the atrial fibrillation incidence at 2 years postcavo-tricuspid isthmus ablation.

Implantable loop recorder for augmenting detection of new-onset atrial fibrillation after typical atrial flutter ablation

Background

Patients with typical atrial flutter (AFL) undergoing successful cavotricuspid isthmus ablation remain at risk for future development of new-onset atrial fibrillation (AF). Conventional monitoring (CM) techniques have shown AF incidence rates of 18%–50% in these patients.

Objectives

To evaluate whether continuous monitoring using implantable loop recorders (ILRs) would enhance AF detection in this patient population.

Methods

Veteran patients undergoing AFL ablation between 2002 and 2019 who completed at least 6 months of follow-up after the ablation procedure were included. We compared new-onset AF detection between those who underwent CM and those who received ILRs immediately following AFL ablation.

Results

A total of 217 patients (age: 66 ± 9 years; all male) participated. CM was used in 172 (79%) and ILR in 45 (21%) patients. Median follow-up duration after ablation was 4.1 years. Seventy-nine patients (36%) developed new-onset AF, which was detected by CM in 51 and ILR in 28 (30% vs 62%, respectively, P < .001). AF detection occurred at 7.7 months (IQR: 4.7–17.5) after AFL ablation in the ILR group vs 41 months (IQR: 23–72) in the CM group (P < .001). Eleven patients (5%) experienced cerebrovascular events (all in the CM group) and only 4 of these patients (36%) were on long-term anticoagulation.

Conclusion

Patients undergoing AFL ablation remain at an increased risk of developing new-onset AF, which is detected sooner and more frequently by ILR than by CM. Improving AF detection may allow optimization of rhythm management strategies and anticoagulation in this patient population.

Long-Term Efficacy of Prophylactic Cavotricuspid Isthmus Ablation during Atrial Fibrillation Ablation in Patients Without Typical Atrial Flutter: a Prospective, Multicentre, Randomized Trial

Background and Objectives

Cavotricuspid isthmus (CTI) block is easily achieved, and prophylactic ablation can be performed during atrial fibrillation (AF) ablation. However, the previous study was too small and short-term to clarify the efficacy of this block.

Methods

Patients who underwent catheter ablation for paroxysmal AF were enrolled, and patients who had previous or induced atrial flutter (AFL) were excluded. We randomly assigned 366 patients to pulmonary vein isolation (PVI) only and prophylactic CTI ablation (PVI vs. PVI+CTI).

Results

There was no significant difference in procedure time between the two groups because most CTI blocks were performed during the waiting time after the PVI (176.8±72.6 minutes in PVI vs. 174.2±76.5 minutes in PVI+CTI, p=0.75). All patients were followed up for at least 18 months, and the median follow-up was 3.4 years. The recurrence rate of AF or AFL was not different in the 2 groups (25.7% in PVI vs. 25.7% in PVI+CTI, p=0.92). The recurrence rate of any AFL was not significantly different in the 2 groups (3.3% in PVI vs. 1.6% in PVI+CTI, p=0.31). The recurrence rate of typical AFL also was not different (0.5% in PVI vs. 0.5% in PVI+CTI, p=0.99).

Conclusions

In this large and long-term follow-up study, prophylactic CTI ablation had no benefit in patients with paroxysmal AF without typical AFL.

Trial Registration

ClinicalTrials.gov Identifier: NCT02031705

Electrophysiological and clinical characteristics of catheter ablation for isolated left side atrial tachycardia over a 10-year period

AIMS

Most left atrial tachycardia (LAT) is associated with atrial fibrillation (AF). The clinical and electrophysiological characteristics and outcomes of LAT without AF have not been investigated. This study sought to determine the long-term ablation outcomes and predictors of recurrence of isolated LAT.

METHODS

This is a single-center study of consecutive patients with isolated LAT. Atrial arrhythmia recurrence was determined from follow-up records of patients who underwent LAT ablation from 2008 to 2017. Clinical and electrophysiologic characteristics associated with atrial arrhythmia recurrence were identified.

RESULTS

A total of 50 patients (53 ± 19 years, 46% male) with 59 LAT (1.16 ± 0.47 per patient) were enrolled. Over a mean follow-up of 37 ± 33 months, atrial arrhythmia recurrence occurred in 22 (44%) patients, 11 with atrial tachycardia (AT) only, five with AF only, and six with concurrent AT and AF. The incidence of pulmonary vein (PV) origins increased significantly in the repeat procedure (P = 0.036). Multivariate analysis identified left ventricular ejection fraction (LVEF) as the only predictor of any atrial arrhythmia recurrence and LAT recurrence, while smoking and identified macroreentrant LAT in the index procedure predicted AF recurrence.

CONCLUSION

This study demonstrated a higher rate of atrial arrhythmia recurrence, including AF, among patients with initially isolated LAT. A lower LVEF predicted any atrial arrhythmia and LAT recurrence, whereas smoking and index macroreentrant AT mechanism predicted long-term AF. PV ATs were frequently observed in recurrent patients irrespective of index procedure origin.

Prophylactic pulmonary vein isolation during cavotricuspid isthmus ablation for atrial flutter: A meta-analysis

BACKGROUND

Atrial arrhythmias (AA), including atrial fibrillation (AF), have been reported in patients after cavotricuspid isthmus (CTI) ablation for typical atrial flutter (AFL). Several studies have examined the effect of performing concomitant pulmonary vein isolation (PVI) with CTI on recurrent AA. These studies were analyzed to determine the overall effect of this approach on recurrent AA.

METHODS

PubMed and Google Scholar were searched for randomized trials comparing the incidence of AA after CTI versus CTI + PVI until June 2018. Only patients without prior history of AF were included in the recurrent AA analysis. All patients were included in the analyses of other clinical outcomes.

RESULTS

Four randomized control trials were included in the meta-analysis. In the recurrent AA analysis, a total of 314 patients were randomized in the studies (n = 158 CTI, n = 156 CTI + PVI). Freedom from AA at 1 year was significantly higher in the CTI + PVI group versus CTI alone (odds ratio [OR] 0.25 [0.14, 0.44] 95% confidence interval [CI], P < 0.00001). A total of 550 patients (n = 336 CTI, n = 214 CTI + PVI) were included in analyses for procedure time, fluoroscopy time, and complications rates. Procedure time and fluoroscopy time were significantly longer in the CTI + PVI group (mean difference [MD]: 103.31 min [94.40, 112.23] 95% CI, P < 0.00001) and (MD: 16.47 min [14.89, 18.05] 95% CI, P < 0.00001), respectively. Total complications were statistically similar between groups.

CONCLUSION

This meta-analysis shows addition of a prophylactic PVI during CTI ablation significantly reduces recurrent AA at 1 year without significantly increasing major complications.

The combination of electroanatomic mapping and minielectrodes in a series of cases of redo procedures

Background

In patients with supraventricular tachycardia, catheter ablation is an important treatment option. However, approximately one quarter of these patients remain symptomatic, so sustainable strategies for the treatment of those patients who do not benefit from the first catheter ablation are required.

Methods

In a series of redo procedures, we investigated the combined use of an electro-anatomic mapping system and an ablation catheter with mini-electrodes.

Results

Catheter ablation was successful in two patients with recurrent common type atrial flutter and one patient with recurrent ectopic atrial tachycardia. In a patient with recurrent perimitral flutter, the ablation procedure had to be stopped early, due to pericardial effusion.

Conclusion

The combination of electro-anatomic mapping and mini-electrodes might be useful, especially in the treatment of ectopic atrial tachycardias, but also in redo procedures of CTI ablations, that require not only the visualization of the tachycardia, but also the detection of a local focus or a local gap. For an optimal use of the ME ablation catheter, the generator settings should be evaluated in further studies.

Coronary Sinus Electrograms May Predict New-onset Atrial Fibrillation After Typical Atrial Flutter Radiofrequency Ablation (CSE-AF)

Background

Complex fractionated electrograms (EGMs) of the coronary sinus electrograms (CSEs) are employed as a target during radiofrequency ablations (RFA) of atrial fibrillation (AF). Anatomically, CSEs includes both of left atrium (LA), coronary sinus musculature and right atrium (RA) electrograms.

Aim

To determine the significance of fractionated CSE and delayed potentials as a predictor of new-onset AF after radiofrequency ablation (RFA) of isolated atrial flutter (AFL).

Methods

Consecutive patients underwent AFL ablation. Fractionated and/or continuous discrete activities were recorded from coronary sinus electrograms during sinus rhythm and during pacing. Earliest CSE to the S nadir or peak R in milliseconds was recorded and considered as propagation delay for EGMs.

Results

Forty patients were included during a mean follow-up period of 55.1± 15.8 months. Twenty patients (50 %) developed AF while the remaining 20 patients maintained sinus rhythm(SR) during the follow-up period. Proximal and mid CSEs were significantly fractionated in AF group compared to group with no AF development (65 % and 60% Vs. 35 % and 30 %, p = 0.03, respectively). However, during pacing from distal duo-decapolar catheter (pole 1-2), distal CSEs alone were significantly fractionated (p < 0.05) compared to SR group. Significant delayed propagation of proximal CSE during pacing and in sinus rhythm were observed in AF group (12.3 ± 9.2 ms vs 7.1 ± 3.6 ms, p = 0.03) and (7.2 ± 2.9 ms Vs 8.1 ± 4.6 ms, p= 0.02) in the same order.

Conclusion

Incidence of AF is associated with fractionated proximal and mid CSE in sinus rhythm and distal CSE during paced rhythm after isolated AFL ablation. Delayed proximal CSE propagation is correlated with AF incidence.

Incidence of new-onset atrial fibrillation after cavotricuspid isthmus ablation for atrial flutter

Aims

In patients with cavotricuspid isthmus (CTI) ablation for atrial flutter (AFL), the decision to hold oral anticoagulation (OAC) often becomes an issue. The purpose of this study was to describe the incidence of the development of atrial fibrillation (AF) after CTI ablation in patients with documented AFL with and without a previous history of AF and to identify risk predictors for the occurrence of AF after CTI.

Methods and results

We included 364 consecutive patients undergoing successful CTI ablation. Thereof, 230 patients (170 male; age 66 ± 11 years) had AFL only (AFL group) and 134 patients (94 male; age 65 ± 11 years) had AFL and previously documented AF (AFL and AF group). Over a mean follow-up of 22 ± 20 months, 163 (71%) patients in the AFL group and 67 (50%) patients in the AFL and AF groups had no documentation of a recurrent atrial arrhythmia (P < 0.001). AF developed in 51 patients (22%) in the AFL group and in 57 (43%) patients in the AFL and AF groups (P < 0.001). In patients without history of AF, left atrial diameter was the only predictor of development of AF (HR 1.058 [95%CI 1.011-1.108], P = 0.016). Multivariate analysis of the total population identified history of AF (HR 1.918 [95%CI 1.301-2.830], P = 0.001) and BMI as predictors for AF development (HR 1.052 [95%CI 1.012-1.093], P = 0.011).

Conclusion

Our results indicate that new-onset AF develops in a significant proportion of patients undergoing CTI for AFL. One should therefore be careful to withhold OAC. Furthermore, pulmonary vein isolation should be considered in conjunction with CTI, particularly in patients with previously documented AF.

Frequency of atrial arrhythmias after atrial flutter ablation and the effect of presenting rhythm on the day of ablation

Radiofrequency catheter ablation of the cavotricuspid isthmus is a proven therapy for typical atrial flutter (AFl); however, in some patients, new atrial arrhythmias (AA) may occur after AFl ablation. This study explored the difference in the occurrence of spontaneous AA after AFl ablation as a function of the patient's presenting rhythm on the day of the AFl ablation. A retrospective study of consecutive patients who underwent AFl ablation at Baylor University Medical Center at Dallas was performed. A total of 188 subjects were included; 50% (94) presented in AFl (Group AFl) on the day of the ablation procedure and 94 presented in sinus rhythm (SR; Group SR). Group AFl patients were older (P < 0.001), more likely to have diabetes (P = 0.03), and more likely to have undergone previous heart surgery (P = 0.03). The median size of the left atrium was 4 cm (range 2.8-6.8) in Group AFl compared with 3.8 cm (range 2.6-5.6) in Group SR (P = 0.009). Atrial fibrillation was induced during the ablation procedure in 7.5% and 21.3% of patients in Groups AFl and SR, respectively (P = 0.007). Overall, 29 of 188 (15.4%) patients developed new AA within 1 year of the procedure, 13.8% in Group AFl vs 17.0% in Group SR (P = 0.57). In conclusion, patients presenting for AFl ablation in SR were younger and healthier but had more atrial fibrillation induced during their ablation procedure, with a trend toward more postablation AA due to additional arrhythmia substrate.

Spatial relationship of sites for atrial fibrillation drivers and atrial tachycardia in patients with both arrhythmias

INTRODUCTION

Atrial fibrillation (AF) often converts to and from atrial tachycardia (AT), but it is undefined if these rhythms are mechanistically related in such patients. We tested the hypothesis that critical sites for AT may be related to regional AF sources in patients with both rhythms, by mapping their locations and response to ablation on transitions to and from AF.

METHODS

From 219 patients undergoing spatial mapping of AF prior to ablation at 3 centers, we enrolled 26 patients in whom AF converted to AT by ablation (n=19) or spontaneously (n=7; left atrial size 42±6cm, 38% persistent AF). Both atria were mapped in both rhythms by 64-electrode baskets, traditional activation maps and entrainment.

RESULTS

Each patient had a single mapped AT (17 reentrant, 9 focal) and 3.7±1.7 AF sources. The mapped AT spatially overlapped one AF source in 88% (23/26) of patients, in left (15/23) or right (8/23) atria. AF transitioned to AT by 3 mechanisms: (a) ablation anchoring AF rotor to AT (n=13); (b) residual, unablated AF source producing AT (n=6); (c) spontaneous slowing of AF rotor leaving reentrant AT at this site without any ablation (n=7). Electrogram analysis revealed a lower peak-to-peak voltage at overlapping sites (0.36±0.2mV vs 0.49±0.2mV p=0.03).

CONCLUSIONS

Mechanisms responsible for AT and AF may arise in overlapping atrial regions. This mechanistic inter-relationship may reflect structural and/or functional properties in either atrium. Future work should delineate how acceleration of an organized AT may produce AF, and whether such regions can be targeted a priori to prevent AT recurrence post AF ablation.

Short-term outcomes of atrial flutter ablation

BACKGROUND

Understanding the factors associated with early readmissions following atrial flutter (AFL) ablation is critical to reduce the cost and improving the quality of life in AFL patients.

METHOD

The study cohort was derived from the national readmission database 2013-2014. International Classification of Diseases, 9th Revision (ICD-9-CM) diagnosis code 427.32 and procedure code 37.34 were used to identify AFL and catheter ablation, respectively. The primary and secondary outcomes were 90-day readmission and complications including in-hospital mortality. Cox proportional regression and hierarchical logistic regression were used to generate the predictors of primary and secondary outcomes respectively. Readmission causes were identified by ICD-9-CM code in primary diagnosis field of readmissions.

RESULT

Readmission rate of 18.19% (n = 1,010 with 1,396 readmissions) was noted among AFL patients (n = 5552). Common etiologies for readmission were heart failure (12.23%), atrial fibrillation (11.13%), atrial flutter (8.93%), respiratory complications (9.42%), infections (7.4%), bleeding (7.39%, including GI bleed-4.09% and intracranial bleed-0.79%) and stroke/TIA (1.89%). Multivariate predictors of 90-day readmission (hazard ratio, 95% confidence interval, P value) were preexisting heart failure (1.30, 1.13-1.49, P < 0.001), chronic pulmonary disease (1.37, 1.18-1.58, P < 0.001), anemia (1.23, 1.02-1.49, P = 0.035), malignancy (1.87, 1.40-2.49, P < 0.001), weekend admission compared to weekday admission (1.23, 1.02-1.47, P = 0.029), and length of stay (LOS) ≥5 days (1.39, 1.16-1.65, P < 0.001). Note that 50% of readmissions happened within 30 days of discharge.

CONCLUSION

Cardiac etiologies remain the most common reason for the readmission after AFL ablation. Identifying high risk patients, careful discharge planning, and close follow-up postdischarge can potentially reduce readmission rates in AFL ablation patients.

2016 Guidelines of the Taiwan Heart Rhythm Society and the Taiwan Society of Cardiology for the management of atrial fibrillation

Atrial fibrillation (AF) is the most common sustained arrhythmia. Both the incidence and prevalence of AF are increasing, and the burden of AF is becoming huge. Many innovative advances have emerged in the past decade for the diagnosis and management of AF, including a new scoring system for the prediction of stroke and bleeding events, the introduction of non-vitamin K antagonist oral anticoagulants and their special benefits in Asians, new rhythm- and rate-control concepts, optimal endpoints of rate control, upstream therapy, life-style modification to prevent AF recurrence, and new ablation techniques. The Taiwan Heart Rhythm Society and the Taiwan Society of Cardiology aimed to update the information and have appointed a jointed writing committee for new AF guidelines. The writing committee members comprehensively reviewed and summarized the literature, and completed the 2016 Guidelines of the Taiwan Heart Rhythm Society and the Taiwan Society of Cardiology for the Management of Atrial Fibrillation. This guideline presents the details of the updated recommendations, along with their background and rationale, focusing on data unique for Asians. The guidelines are not mandatory, and members of the writing committee fully realize that treatment of AF should be individualized. The physician's decision remains most important in AF management.

Risk and outcome after ablation of isthmus-dependent atrial flutter in elderly patients

Purpose of the research

To study the influence of age on the clinical presentation and long-term outcome of patients referred for atrial flutter (AFL) ablation. Age-related differences have been reported regarding the prognosis of arrhythmias.

Methods

A total of 1187 patients with a mean age 65±12 years consecutively referred for AFL ablation were retrospectively analyzed in the study.

Results

445 (37.5%) patients were aged ≥70 (range 70 to 93) among which 345 were aged 70 to 79 years (29.1%) and 100 were aged ≥80 (8.4%). In multivariable analysis, AFL-related rhythmic cardiomyopathy and presentation with 1/1 AFL were less frequent (respectively adjusted OR = 0.44, 0.27–0.74, p = 0.002 and adjusted OR = 0.29, 0.16–0.52, p<0.0001). AFL ablation-related major complications were more frequent in patients ≥70 although remained lower than 10% (7.4% in ≥70 vs. 4.2% in <70, adjusted OR = 1.74, 1.04–2.89, p = 0.03). After 2.1±2.7 years, AFL recurrence was less frequent in patients ≥70 (adjusted OR = 0.54, 0.37–0.80, p = 0.002) whereas atrial fibrillation (AF) occurrence was as frequent in the 70–79 and ≥80 age subsets. As expected, cardiac mortality was higher in older patients. Patients aged ≥80 also had a low probability of AFL recurrence (5.0%) and AF onset (19.0%).

Conclusions

Older patients represent 37.5% of patients referred for AFL ablation and displayed a <10% risk of ablation-related complications. Importantly, AFL recurrences were less frequent in patients ≥70 while AF occurrence was as frequent as in patients <70. Similar observations were made in patients ≥80 years. AFL ablation appears to be safe and efficient and should not be ruled out in elderly patients.

New-onset atrial fibrillation after cavotricuspid isthmus ablation: identification of advanced interatrial block is key

AIMS

A significant proportion of patients develop atrial fibrillation (AF) following cavotricuspid isthmus (CTI) ablation for typical atrial flutter (AFl). The objective of this study was to assess whether the presence of advanced interatrial block (aIAB) was associated with an elevated risk of AF after CTI ablation in patients with typical AFl and no prior history of AF.

METHODS AND RESULTS

This study included patients with typical AFl and no prior history of AF that were referred for CTI ablation. Patients were excluded when they had received repeat ablations or did not demonstrate a bidirectional block. In all patients, a post-ablation electrocardiogram (ECG) in sinus rhythm was evaluated for the presence of aIAB, defined as a P-wave duration ≥120 ms and biphasic morphology in the inferior leads. New-onset AF was identified from 12-lead ECGs, Holter monitoring, and device interrogations. The cohort comprised 187 patients (age 67 ± 10.7 years; ejection fraction 55.8 ± 11.2%). Advanced interatrial block was detected in 18.2% of patients, and left atrium was larger in patients with aIAB compared with those without aIAB (46.2 ± 5.9 vs. 43.1 ± 6.0 mm; P = 0.01). Over a median follow-up of 24.2 months, 67 patients (35.8%) developed new-onset AF. The incidence of new-onset AF was greater in patients with aIAB compared with those without aIAB (64.7 vs. 29.4%; P < 0.001). After a comprehensive multivariate analysis, aIAB emerged as the strongest predictor of new-onset AF [odds ratio (OR) 4.2, 95% confidence interval (CI): 1.9-9.3; P < 0.001].

CONCLUSION

Advanced interatrial block is a key predictor for high risk of new-onset AF after a successful CTI ablation in patients with typical AFl.

Prognostic value of atrial fibrillation inducibility after right atrial flutter ablation

BACKGROUND

Patients with typical right atrial flutter (AFL) may also have underlying atrial fibrillation (AF) or be at high risk of developing AF. Inducibility of AF among patients undergoing AFL ablation may be an important predictor of future occurrence of AF and may be useful in guiding management of this patient population.

OBJECTIVE

This study aimed to determine whether inducibility of AF at the time of AFL ablation is independently associated with the risk of future AF.

METHODS

Attempt at induction of AF by burst pacing was performed in consecutive patients who underwent AFL ablation. Time to incidence of AF after AFL ablation was examined using multivariable Cox proportional hazards models. All analyses were stratified by a history of AF.

RESULTS

A total of 175 patients were retrospectively evaluated over a median follow-up period of 482 days. In patients without a documented history of AF (n = 93), the incidence of AF after AFL ablation was 18.7 per 100 person-years. In these patients, inducible AF was strongly associated with the future development of AF (adjusted hazard ratio 15.99; 95% confidence interval 5.10-50.12). In contrast, in patients with a documented history of AF (n = 82), the incidence of AF after AFL ablation was 59.3 per 100 person-years and inducible AF was not associated with the future development of AF (adjusted hazard ratio 1.26; 95% confidence interval 0.74-2.14).

CONCLUSION

Inducibility of AF after AFL ablation is strongly and independently associated with the risk of future AF among patients without a history of AF but not among patients with a history of AF.

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.

Acute success and short-term follow-up of catheter ablation of isthmus-dependent atrial flutter; a comparison of 8 mm tip radiofrequency and cryothermy catheters

Objectives

To compare the acute success and short-term follow-up of ablation of atrial flutter using 8 mm tip radiofrequency (RF) and cryocatheters.

Methods

Sixty-two patients with atrial flutter were randomized to RF or cryocatheter (cryo) ablation. Right atrial angiography was performed to assess the isthmus. End point was bidirectional isthmus block on multiple criteria. A pain score was used and the analgesics were recorded. Patients were followed for at least 3 months.

Results

The acute success rate for RF was 83% vs 69% for cryo (NS). Procedure times were similar (mean 144 ± 48 min for RF, vs 158 ± 49 min for cryo). More applications were given with RF than with cryo (26 ± 17 vs. 18 ± 10, p < 0.05). Fluoroscopy time was longer with RF (29 ± 15 vs. 19 ± 12 min, p < 0.02). Peak CK, CK-MB and CK-MB mass were higher, also after 24 h in the cryo group. Troponin T did not differ. Repeated transient block during application (usually with cryoablation) seemed to predict failure. Cryothermy required significantly less analgesia (p < 0.01), and no use of long sheaths (p < 0.005).

The isthmus tended to be longer in the failed procedures (p = 0.117). This was similar for both groups, as was the distribution of anatomic variations. Recurrences and complaints in the successful patients were similar for both groups, with a very low recurrence of atrial flutter after initial success.

Conclusions

In this randomized study there was no statistical difference but a trend to less favorable outcome with 8 mm tip cryocatheters compared to RF catheters for atrial flutter ablation. Cryoablation was associated with less discomfort, fewer applications, shorter fluoroscopy times and similar procedure times. The recurrence rate was very low. Cryotherapy can be considered for atrial flutter ablation under certain circumstances especially when it has been used previously in the same patient, such as in an AF ablation.

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.