Piotr Buchta

Prospective, multicenter validation of a clinical risk score for left atrial arrhythmogenic substrate based on voltage analysis: DR-FLASH score

BACKGROUND Left atrial (LA) low-voltage areas (LVAs) are frequently observed in patients with atrial fibrillation (AF) and may predict AF recurrence after catheter ablation. OBJECTIVE The aim of this study was to develop and validate a clinical tool to identify LVAs that are associated with AF recurrence after pulmonary vein isolation (PVI). METHODS In a cohort of 238 patients, voltage maps were created during LA procedures. LVAs were defined as areas with electrogram amplitudes <0.5 mV. On the basis of regression analysis, predictors of LA substrate were identified. These parameters were used to establish a dedicated risk score (DR-FLASH score, based on diabetes mellitus, renal dysfunction, persistent form of AF, LA diameter >45 mm, age >65 years, female sex, and hypertension). This risk score was then prospectively validated in a multicenter cohort of 180 patients. The association of the score with long-term recurrence of atrial arrhythmias after circumferential PVI was tested in a retrospective cohort of 484 patients. RESULTS The DR-FLASH score effectively identified LVA substrate (C statistic = 0.801, P < .001). In the prospective multicenter validation cohort, the predictive value of the DR-FLASH score was confirmed (C statistic = 0.767, P < .001). The probability for the presence of LA substrate increased by a factor of 2.2 (95% confidence interval [CI] 1.6-2.9, P < .001) with each point scored. Furthermore, the risk of AF recurrence after PVI increased by a factor of 1.3 (95% CI 1.1-1.5, P < .001) with every additional point and was almost 2 times higher in patients with a DR-FLASH score >3 (odds ratio 1.7, 95% CI 1.1-2.8, P = .026). CONCLUSION The DR-FLASH score may be useful to identify patients who may require extensive substrate modification instead of PVI alone.

Prevalence and predictors of worsened left ventricular diastolic dysfunction after catheter ablation of atrial fibrillation

BACKGROUND The interactions between atrial fibrillation (AF) and left ventricular diastolic dysfunction (LVDD) are complex and not well defined. Despite the high prevalence of LVDD in the AF population, therapies for LVDD remain limited. Previous studies have suggested that restoration of sinus rhythm with catheter ablation has a positive effect on LVDD, but the prevalence and predictors for worsened LVDD are unknown. METHODS 70 consecutive patients included in prospective AF catheter ablation registry (61±10 years, 66% male) with paroxysmal (n=40) or persistent AF (n=30) were examined by transthoracic echocardiography, before and 12 months after ablation. LVDD was classified according to current guidelines. Rhythm outcome of the ablation was verified by serial 7-day Holter ECG. RESULTS LVDD was present in 27 patients (38%) at baseline and in 33 patients (47%) at 12 months follow-up (p=.327). An improvement of LVDD was observed in 13 patients (19%), an aggravation was found in 19 (27%), while it was unchanged in the remaining 38 patients (54%). In uni- and multivariable regression analysis, total ablation time (OR 1.611 per 10 min ablation time, 95% CI 1.088-2.386, p=.017) was associated with LVDD progression, while neither baseline characteristics nor rhythm during follow-up influenced LVDD alterations. There was no association between echocardiographic deterioration and symptoms. CONCLUSIONS Catheter ablation of AF can worsen LVDD in a substantial proportion of patients with more aggressive ablation leading to aggravation of LVDD. While there are no apparent negative short-term effects, long-term consequences need to be determined.

Staged hybrid ablation for persistent and longstanding persistent atrial fibrillation effectively restores sinus rhythm in long-term observation

Introduction Hybrid ablation (HABL) of atrial fibrillation combining endoscopic, minimally invasive, closed chest epicardial ablation with endocardial CARTO-guided accuracy was introduced to overcome the limitations of current therapeutic options for patients with persistent (PSAF) and longstanding persistent atrial fibrillation (LSPAF). The purpose of this study was to evaluate the procedural safety and feasibility as well as effectiveness of HABL in patients with PSAF and LSPAF 1 year after the procedure. Material and methods The study is a single-center, prospective clinical registry. From 07/2009 to 12.2014, 90 patients with PSAF (n = 39) and LSPAF (n = 51), at the mean age of 54.8 ±9.8, in mean EHRA class 2.6, underwent HABL. 64.4% of patients had a history of prior cardioversion or catheter ablation. Thirteen patients had LVEF less than 35%. Mean AF duration was 4.5 ±3.7 years. Patients were scheduled for 3-, 6- and 12-month follow-up with 7-day Holter monitoring. Results At 6 months after the procedure 78% (54/69) of patients were in SR. At 12 months after the procedure 86% (59/69) were in SR and 62.3% (43/69) in SR and off class I/III antiarrhythmic drugs (AADs). Only 1% (1/69) of patients required a repeat ablation for atrial flutter. A significant decrease in LA dimension and an increase in LVEF were noted. Conclusions A combination of epicardial and endocardial RF ablation should be considered as a treatment option for patients with persistent and long-standing persistent atrial fibrillation as it is safe and effective in restoring sinus rhythm.

Changing coronary sinus activation during catheter ablation of isthmus-dependent right atrial flutter: what is the mechanism?

A 69-year-old woman was referred for cavotricuspid isthmus ablation due to typical isthmus-dependent right atrial flutter. During ablation, intracardiac activation sequence in coronary sinus (CS) changed without altering the cycle length or the P-wave morphology. This suggests that interatrial connection via CS was blocked and left atrium (LA) was activated from Bachmanns bundle or/and connections between fossa ovalis and LA.

Atrioventricular nodal re-entrant tachycardia mimicking ventricular tachycardia on the surface electrocardiogram.

Address for correspondence: Dr. Adam J. Wojtaszczyk, Third Department of Cardiology, School of Medicine with the Division of Dentistry in Zabrze, Medical University of Silesia, ul. M. Curie-Skłodowskiej 9, 41–800 Zabrze, Poland, e-mail: adam.wojtaszczyk@gmail.com Conflict of interest: none declared Kardiologia Polska Copyright

The influence of ablation power reduction associated with oesophagus location on pulmonary vein isolation results in patients with paroxysmal atrial fibrillation: six-month follow-up

BACKGROUND Catheter ablation of atrial fibrillation (AF) could be associated with a thermal oesophageal (EO) injury. To avoid this complication intraluminal EO temperature monitoring and ablation power reduction at the areas with excessive heating could be used. However, the reduced energy could limit the ablation lesion depth, without creation of lasting transmural scar and influence on long-term ablation results. AIM The primary goal was to evaluate the homogeneity of forced ablation power reduction due to excessive EO heating in different parts of the left atrium. The secondary goal was to assess the influence of power reduction in different EO locations on long-term AF recurrence. METHODS We examined retrospectively 109 consecutive patients with symptomatic, medically refractory paroxysmal AF, who underwent pulmonary vein isolation using radiofrequency ablation. In 40.4% of the patients the EO course was central (group B) left atrium posterior wall, in 31.2% it was left sided (group A), and in 28.4% it was right sided (group C). RESULTS The maximal measured temperature (41.0 ± 1.0 vs. 39.2 ± 1.5 vs. 40.6 ± 0.7°C) and forced ablation power (15.9 ± 5.6 vs. 23.5 ± 6.1 vs. 17.4 ± 5.7 W) differed significantly according to the EO course (A, B, C, respectively). In six-month follow-up 76.15% of patients were free of arrhythmias. There was no statistically significant difference between groups (A-C) regarding the AF recurrence rate: 32.4% vs. 20.5% vs. 19.4% (p = 0.37). CONCLUSIONS The maximal intraluminal EO temperatures and the necessary level of power reduction during AF ablation are inhomogeneous in different parts of the left atrium, but they are not associated with different six-month follow-up results.

TCT-116 Periprocedural Checklist In Catheterization Laboratory Is Associated With Reduced Rate Of Treatment Complications

Withdrawn