Outcome after catheter ablation for left atrial flutter

Atypical atrial flutter ablation: follow-up and predictors of arrhythmia recurrence

BACKGROUND

Ablation techniques have evolved greatly with advances in high-density 3D mapping systems over the last few years. Some patients develop atypical atrial flutter (AAFL) after pulmonary vein isolation (PVI). The data regarding follow-up after AAFL ablation as well as predictors of arrhythmia recurrence are lacking. This analysis aims to report procedure success rates and establish predictors of long-term success.

METHODS AND RESULTS

This retrospective cohort study included 45 patients (median age: 69 years; 40% female) who qualified for their first AAFL after PVI. The procedures were performed with the use of conventional ablation-index-guided ThermoCool Smarttouch SF and QDOT MICRO catheters. Freedom from arrhythmia recurrence was used as a primary end point. After 52 weeks of follow-up, 60% of patients suffered from arrhythmia recurrence, but over 70% of the studied cohort reported symptom improvement. In multivariate analysis, class I antiarrhythmics prescription (HR = 0.24 [95% CI 0.06-0.94], p = 0.04) was associated with the lack of arrhythmia recurrence during the follow-up, while cardioversion during procedure was associated with increased risk of arrhythmia recurrence (HR = 7.05 [95% CI 2.09-23.72], p = 0.002).

CONCLUSIONS

Long-term success of AAFL ablation procedures is not satisfactory despite improvement in symptoms. Class I antiarrhythmics prescription at the discharge contributes to higher chances of sinus rhythm maintenance, whereas cardioversion during the procedure is related to increased risk of arrhythmia recurrence.

Atypical atrial flutter catheter ablation in the era of high-density mapping

BACKGROUND

Mapping and ablating atypical atrial flutters (AAFLs) have evolved greatly with advances in high-density 3D mapping systems over the last years.

METHODS

The objectives are to evaluate the feasibility of AAFL catheter ablation based on high-density mapping and minimizing entrainment and to better characterize AAFL circuits. Consecutive patients who underwent AAFL ablation using the EnSite Precision™ system and HD Grid™ mapping catheter (Abbott, Chicago, IL) between 06/2018 and 1/2022 were included. Mitral isthmus-dependent and roof-dependent AAFLs were classified as conventional circuits. All other AAFL circuits were classified as non-conventional circuits and were defined based on the location of the critical isthmus.

RESULTS

Sixty-two patients underwent AAFL ablation (mean age 68±11 years). A total of 95 AAFLs were mapped and 92 (97%) were successfully ablated. Fifty-three (85%) patients had a previous AF/AFL ablation. Forty-four (46%) AAFL circuits were classified as conventional and 51 (54%) as non-conventional. Conventional AAFL circuits had longer critical isthmuses (19.0±9.0 vs 10.8±6.3mm, p<0.001), a lower prevalence of slow conduction at the critical isthmus (59% vs 86%, p=0.005), and a longer radiofrequency time to AAFL termination (117±119 vs 51±66 s, p=0.002). Entrainment was attempted in 19 (20%) flutters and its use declined significantly over the study period. Procedural success rates remained high whether entrainment was used or not. Freedom of any atrial tachycardia was 65% over a follow-up of 13.8±9.0 months.

CONCLUSIONS

AAFL catheter ablation can be achieved with high procedural success rate using a contemporary strategy based on high-density mapping alone. Non-conventional circuits are frequent and present unique electrophysiological characteristics.

Validation of the national Danish ablation database: a retrospective, registry-based validation study

Aim.To validate the National Danish Ablation Database (NDAD) by investigating to what extent data in NDAD correspond to medical records.Type of study. Non-blinded, registry-based, retrospective, validation study. Material and methods. A sample of patients who underwent ablation for atrial fibrillation in Denmark between 1 January 2016 and 31 December 2016 were included. By utilizing medical records as gold standard, positive predictive (PPV) and negative predictive values (NPV) for NDAD were assessed and presented as five main categories: arrhythmia characteristics, demographics, cardiac history, complications, and medication. PPV's and NPV's exceeding 90% were considered as high agreement. Results. 597 patients (71.0% males) were included in the study. Median age was 63.1 (IQR: 54.9-68.4) years. The median PPV and NPV estimates across all variables were respectively 90.4% (95% CI: 68%-95.2%) (PPV) and 99.4% (95% CI: 98.4%-99.8%) (NPV) at baseline, and 91.7% (95% CI: 67.4%-95.4%) (PPV) and 99.3% (98.2%-99.3%) (NPV) at follow-up. Conclusion. The data registered in NDAD agrees to a great extent with the patients' medical records, suggesting NDAD is a database with high validity. As a result of low complication rate, the PPV- and NPV-estimates among complication variables were prone to somewhat greater uncertainty compared to the rest.

Two-year outcomes of pulmonary vein isolation and cava-tricuspid isthmus radiofrequency ablation vs pharmacological only antiarrhythmic therapy: a single center experience

The benefit of radiofrequency ablation (RFA) in rhythm control in atrial fibrillation (AF) and flutter patients is uncertain, but risk of death, arrhythmia recurrence and other post ablation complications remains high. Existing data on the impact of pulmonary vein isolation and cava-tricuspid isthmus RFA on long-term prognosis of patients with AF and flutter and its advantage over pharmacological antiarrhythmic therapy (AAT) are insufficient and contradictory. The aim: we sought to evaluate two-year outcomes of pulmonary vein isolation and cava-tricuspid isthmus RFA vs pharmacological only AAT according to a single center experience. Material and methods: we enrolled 174 patients after pulmonary vein isolation RFA, cava-tricuspid isthmus RFA and their combination and 122 patient who did not undergo RFA and got pharmacological AAT only. Results: there was no significant difference in mortality between the RFA and AAT only groups (5.8 % and 9.0 % respectively) with the same structure of causes of death. The Caplan-Meyer curve analysis demonstrated better survivance (p=0.031) after RFA just during first year of observation. RFA effectiveness in arrhythmia relapse prevention was the highest for cava-tricuspid isthmus RFA procedure and worst – in group of combined pulmonary vein isolation and cava-tricuspid isthmus procedures. RFA showed an advantage over AAT in smaller quantities of non-fatal cardiovascular events (p<0.001) and cardiovascular hospitalizations (p=0.0026). Conclusions: RFA of pulmonary vein isolation and cava-tricuspid isthmus RFA decrease arrhythmia episodes frequency, risk of non-fatal cardiovascular events and cardiovascular hospitalizations. Timely combined PVI and CTI procedure is associated with worsening of all outcomes.

Atypical atrial flutter: review of mechanisms, advances in mapping and ablation outcomes

PURPOSE OF REVIEW

Atrial flutter (AFL) is the second most prevalent arrhythmia after atrial fibrillation (AF). It is a macro-reentrant tachycardia that is either cavotricuspid isthmus dependent (typical) or independent (atypical). This review aims at highlighting mechanism, diagnosis and treatment of atypical AFL and the recent developments in electroanatomic mapping.

RECENT FINDINGS

Incidence of left AFL is at an exponential rise presently with increase in AF ablation rates. The mechanism of left AFL is most often peri-mitral, roof-dependent or within pulmonary veins in preablated, in contrast to posterior or anterior wall low voltage areas in ablation naïve patients. Linear lesions, compared to pulmonary vein isolation alone, have higher incidence of atypical right or left AFL. Catheter ablation for atypical AFL is associated with lower rates of thromboembolic events, transfusions, and length of stay compared to typical AFL.

SUMMARY

Advances in mapping have allowed rapid simultaneous acquisition of automatically annotated points in the atria and identification of details of macro-reentrant circuits, including zones of conduction block, scar, and slow conduction.

Influence of common zones of low-amplitude activity on the mechanism and treatment of atrial arrhythmias

Background: The treatment of left atrial flutter is a problem that requires a deep understanding of the underlying complex mechanism of arrhythmia. Although a considerable experience exists already in understanding the mechanisms underlying atrial flutter after ablation or surgery, little is known about atypical forms of atrial flutter in patients who have not previously undergone ablation or other cardiac surgery. Clinical case description: We present a clinical case of interventional treatment of a patient with atypical atrial flutter who had not previously undergone surgical or interventional heart surgery. This clinical observation demonstrates the role of common zones of low-amplitude activity on the mechanism and treatment of atrial arrhythmias. Widespread areas of low-amplitude activity in the left atrium can create barriers to the propagation of excitation, which can cause atypical atrial flutter. Conclusion: When performing a surgical intervention, high-density mapping will help to visualize the mechanism of this arrhythmia. Understanding the mechanism of atypical atrial flutter will help to minimize the RF exposure during the treatment.

[Atrial Flutter: up-to-date Problem Evaluation with Clinical Positions]

The review provides current ideas about the etiology and prevalence of atrial flutter (AF), mechanism and substrate of arrhythmogenesis, and principles of clinical and electrophysiological classification of this arrhythmia. Methods for conservative and surgical treatments of AF, including their comparative aspect, are described in detail. The review presented recent data on efficacy and potential risks of different approaches to reversing the arrhythmia. The authors indicated a need for early diagnosis and strict control of the sinus rhythm in AF, which would help a successful intervention not only to completely cure the existing arrhythmia but also to prevent other heart rhythm disorders, primarily atrial fibrillation.