[VT ablation - a technically complex procedure]. / Ablationsbehandling hos patienter med strukturell hjärtsjukdom.

Ventricular tachycardia (VT) in patients with structural heart disease is potentially life threatening, and most patients have an indication for an implantable cardioverter-defibrillator (ICD). Catheter ablation is an effective therapeutic strategy to reduce the risk of VT recurrence and subsequent ICD therapies. However, VT ablation is a technically complex procedure with significant risks and should be performed in experienced centers with appropriate resources. While several reports on outcome and procedural risks have been published, there is currently no data from Sweden. In addition to this literature review, we have analyzed VT ablation outcome data from our center. In 2021 and 2022, 68 VT ablations were performed in 60 patients with structural heart disease. After a median follow-up of 20 months, 18 percent had recurrent VT and there were 2 major adverse events (stroke and complete atrioventricular block). Seven patients died from non-arrhythmia related causes during follow-up. A large proportion (68 percent) were subacute procedures which are associated with a higher periprocedural risk. Referral for VT ablation earlier in the course of disease progression may likely further improve outcomes.

Gastroesophageal reflux disease symptoms and risk of atrial fibrillation in a population-based cohort study (the HUNT study).

AIMS: Gastroesophageal reflux disease (GERD) may influence the risk of atrial fibrillation (AF). We investigated the association between symptoms of GERD and AF in the Trøndelag Health Study (HUNT). METHODS: The study cohort comprised 34,120 adult men and women initially free of AF with information on GERD symptoms. Participants were followed from the baseline clinical examination (1 October 2006 to 30 June 2008) to March 31, 2018. RESULTS: During a median follow-up of 8.9 years, 1,221 cases of AF were diagnosed. When looking at the whole population, participants with much GERD symptoms did not have an increased risk of AF (HR: 1.01; CI: 95%, 0.82 to 1.24) while participants with little GERD symptoms had a 14% lower risk of AF compared those with no GERD symptoms (HR: 0.86; CI: 95%, 0.76 to 0.97). Among younger participants (<40 years of age), the risk of AF had a trend towards increased risk with increasing symptom load of GERD (little GERD symptoms, HR: 3.09; CI: 95%, 0.74 to 12.94 and much GERD symptoms, HR: 5.40; 95% CI: 0.82 to 35.58). Among older participants (≥65 years of age), we saw a slightly reduced risk of AF in participants with little symptoms (HR: 0.84; CI: 0.72 to 0.97) and no association among those with much GERD symptoms (HR: 1.06; 95% CI: 0.82 to 1.36). CONCLUSION: We did not find support for a clinically important association between symptoms of GERD and AF across all age groups but for some younger people, GERD might play a role in the development of AF. However, our estimates for this age group were very imprecise and larger studies including younger individuals are warranted.

Reduced dementia risk in patients with optimized anticoagulation therapy undergoing atrial fibrillation ablation.

BACKGROUND: Atrial fibrillation (AF) is associated with the development of dementia, and observational studies have shown that oral anticoagulation and catheter ablation reduce dementia risk. However, such studies did not consistently report on periprocedural anticoagulation and long-term oral anticoagulation coverage, for which reason the separate effect of AF ablation on dementia risk could not be established. OBJECTIVE: We evaluated the protective effect of AF ablation in a large cohort of patients who received optimized anticoagulation and compared them with patients who were managed medically. METHODS: We retrospectively included 5912 consecutive patients who underwent first-time catheter ablation for AF between 2008 and 2018 and compared them with 52,681 control individuals from the Swedish Patient Register. Propensity score matching produced 2 cohorts of equal size (n = 3940) with similar baseline characteristics. Dementia diagnosis was identified by International Classification of Diseases codes from the patient register. RESULTS: Most propensity score-matched patients were taking an oral anticoagulant at the start (94.5%) and end (75.0%) of the study. Mean follow-up was 4.9 ± 2.8 years. Catheter ablation was associated with lower risk for the dementia diagnosis compared with the control group (hazard ratio [HR], 0.44; 95% confidence interval [CI], 0.22-0.86; P = .017). The result was similar when including patients with a stroke diagnosis before inclusion (HR, 0.50; 95% CI, 0.28-0.89; P = .019) and after adjustment for the competing risk of death (HR, 0.41; 95% CI, 0.20-0.86; P = .018). CONCLUSION: Catheter ablation of AF in patients with optimized oral anticoagulation therapy was associated with a reduction in dementia diagnosis, even after adjustment for potential confounders and for competing risk of death.

Predictors of low-voltage zones in patients with persistent atrial fibrillation eligible for catheter ablation: An observational study.

INTRODUCTION: The presence of low-voltage zones (LVZs) in the left atrium (LA) is associated with the recurrence of atrial fibrillation (AF) following pulmonary vein isolation (PVI). However, there is variability and conflict in the data regarding predictors of LVZs as reported in previous studies. The objective of this study was to identify predictors for the presence of LVZs in a cohort of patients with persistent AF. METHODS: The study prospectively enrolled 439 patients with persistent AF who were scheduled for ablation. Voltage map of the LA was collected using a multipolar catheter. An LVZ was defined as an area of ≥3 cm2 exhibiting a peak-to-peak bipolar voltage of <0.5 mV. RESULTS: The mean age of the cohort was 65.3 ± 8.6 years and 26.4% were female. Additionally, 25.7% had significant LVZs, most frequently located in the anterior wall of the LA. Multivariable analysis identified the following independent predictors for LVZ: advanced age (OR [odds ratio] = 1.08, 95% CI [confidence interval] = 1.03-1.13, p = .002); female sex (OR = 4.83, 95% CI = 2.66-8.76, p < .001); coronary artery disease (CAD) (OR = 3.20, 95% CI = 1.32-7.77, p = .01) and enlarged LA diameter (OR = 1.10, 95% CI = 1.04-1.17, p = .001). The area under the curve (AUC) of the receiver operating characteristic (ROC) curve for the final model was 0.829. CONCLUSION: Approximately 25% of the patients with persistent AF had LVZs. Advanced age, female sex, CAD, and a larger LA were independent predictors for LVZs with the model demonstrating a very good AUC for the ROC curve. These findings hold the potential to be used to tailor the ablation procedure for the individual patient.

Risk assessment in patients with symptomatic and asymptomatic pre-excitation.

AIMS: Controversy remains as to whether the exercise stress test (EST) is sufficient for risk evaluation in patients with pre-excitation. This study aims to clarify the usefulness of EST in risk stratification in both asymptomatic and symptomatic patients presenting with pre-excitation. METHODS AND RESULTS: This prospective study includes consecutive asymptomatic and symptomatic patients with pre-excitation referred for risk assessment. All participants performed an incremental EST (bicycle) prior to an electrophysiology study (EPS). Primary data from the EST included loss of pre-excitation during exercise, and primary data from the EPS included the measurement of accessory pathway effective refractory period (APERP), shortest pre-excited RR interval (SPERRI), and inducible arrhythmia with the use of a beta-adrenergic receptor agonist if deemed necessary. One hundred and sixty-four patients (59 asymptomatic, 105 symptomatic) completed an EST and EPS. Forty-five patients (27%) demonstrated low-risk findings on EST, of which 19 were asymptomatic and 26 were symptomatic. Six patients with low-risk EST findings had SPERRI/APERP ≤ 250 ms at EPS, and two of them were asymptomatic. The sensitivity, specificity, positive predictive value, negative predictive value (NPV), and accuracy of low-risk EST for excluding patients with SPERRI/APERP ≤ 250 ms were 40, 91, 87, 51, and 60%, respectively. The number of patients with inducible arrhythmia at EPS was similar in the asymptomatic (36, 69%) and symptomatic (73, 61%) groups. CONCLUSION: Sudden loss of pre-excitation during EST has a low NPV in excluding high-risk APs. The EPS with the use of isoproterenol should be considered to accurately assess the risk of patients with pre-excitation regardless of symptoms (ClinicalTrials.gov Identifier: NCT03301935).

Association between catheter ablation of atrial fibrillation and mortality or stroke.

OBJECTIVE: Catheter ablation of atrial fibrillation effectively reduces symptomatic burden. However, its long-term effect on mortality and stroke is unclear. We investigated if patients with atrial fibrillation who undergo catheter ablation have lower risk for all-cause mortality or stroke than patients who are managed medically. METHODS: We retrospectively included 5628 consecutive patients who underwent first-time catheter ablation for atrial fibrillation between 2008 and 2018 at three major Swedish electrophysiology units. Control individuals with an atrial fibrillation diagnosis but without previous stroke were selected from the Swedish National Patient Register, resulting in a control group of 48 676 patients. Propensity score matching was performed to produce two cohorts of equal size (n=3955) with similar baseline characteristics. The primary endpoint was a composite of all-cause mortality or stroke. RESULTS: Patients who underwent catheter ablation were healthier (mean CHA2DS2-VASc score 1.4±1.4 vs 1.6±1.5, p<0.001), had a higher median income (288 vs 212 1000 Swedish krona [KSEK]/year, p<0.001) and had more frequently received university education (45.1% vs 28.9%, p<0.001). Mean follow-up was 4.5±2.8 years. After propensity score matching, catheter ablation was associated with lower risk for the combined primary endpoint (HR 0.58, 95% CI 0.48 to 0.69). The result was mainly driven by a decrease in all-cause mortality (HR 0.51, 95% CI 0.41 to 0.63), with stroke reduction showing a trend in favour of catheter ablation (HR 0.75, 95% CI 0.53 to 1.07). CONCLUSIONS: Catheter ablation of atrial fibrillation was associated with a reduction in the primary endpoint of all-cause mortality or stroke. This result was driven by a marked reduction in all-cause mortality.

Elite female endurance athletes are at increased risk of atrial fibrillation compared to the general population: a matched cohort study.

OBJECTIVE: Previous studies have found that endurance sport activity is associated with an increased risk of atrial fibrillation (AF) in men. However, it remains unclear whether endurance sports also influence the risk of AF in women. We aimed to examine whether participation in endurance sports may affect the risk of AF in female athletes. METHODS: We conducted a retrospective matched cohort study of top Swedish female endurance athletes (n=228) and reference individuals (n=1368) from the general population using the Swedish Total Population Register individually matched with a 6:1 ratio of female athletes. The athlete cohort was created by combining all Swedish women who ran the Stockholm Marathon faster than 3 hours 15 min in any of the races between 1979 and 1991, all women competing in the Swedish athletic national championships in the 10 000 metre race, and the top-ranked Swedish cyclists during the same period. We used the National Patient Register to determine whether the participants were diagnosed with AF. RESULTS: Mean age at the start of follow-up was 32 (SD±8.5) years. During follow-up (mean 28.8 years; SD±4.4), 33 cases of AF were diagnosed, including 10 (4.4%) among athletes and 23 (1.7%) among references. The HR for female athletes compared with the reference population was 2.56 (95% CI 1.22 to 5.37) in the univariable model and 3.67 (95% CI 1.71 to 7.87) after adjustment for hypertension. CONCLUSION: Elite female endurance athletes are at increased risk of AF than the general population.

Validation of diagnostic accuracy of a handheld, smartphone-based rhythm recording device.

AIM: Evaluation of the diagnostic accuracy of a rhythm recording device, for detection of atrial tachyarrhythmia (ATA) and atrial fibrillation (AF) compared to 12-lead-electrocardiogram (12-L-ECG). RESEARCH DESIGN AND METHODS: Two hundred 12-L-ECGs (reference standard) and Coala Heart Monitor (CHM) recordings (index test) were collected from 189 patients. Two electrophysiologists independently performed manual analysis of all 12-L-ECGs and CHM recordings in random order. The CHM recordings were also analyzed by an automatic algorithm and compared to the results of the reference standard. RESULTS: Manual analysis of CHM for ATA showed a sensitivity of 98.9% (95% confidence interval (CI): 94.0-100) and a specificity of 100% (CI: 96.6-100). Manual analysis for AF had a sensitivity of 100% (CI: 95.3-100) and a specificity of 97.5% (CI: 93.0-99.5). Automatic analysis for ATA showed a sensitivity of 93.5% (CI: 86.3-97.6) and a specificity of 92.6% (CI: 85.9-96.7). Automatic analysis for AF showed a sensitivity of 97.4% (CI: 91.0-99.7) and a specificity of 86.1% (CI: 78.6-91.7). CONCLUSION: CHM has a very high accuracy for ATA and AF in manual analysis and a high accuracy for ATA and AF in automatic analysis, making the device suitable for screening.

Electrical cardioversion for early recurrences post pulmonary vein isolation.

BACKGROUND: To study the association between timing and success of electrical cardioversion (ECV) for the treatment of early recurrences (ERs) of atrial fibrillation post pulmonary vein isolation (PVI) on long-term rhythm outcome. METHODS: Data of 133 patients ablated for paroxysmal or persistent atrial fibrillation receiving ECV for ERs, i.e., atrial tachyarrhythmia recurrences within 90 days post ablation were analyzed. During 1-year follow-up, patients were screened for late recurrences (LRs), i.e., recurrences after the blanking period. RESULTS: In 114 patients (85.7%), ECV was successful compared to 19 patients (14.3%) with failed ECV. A higher body mass index (odds ratio (OR) 1.19 (95% CI 1.02-1.39), p = 0.029), a lower left ventricular ejection fraction (OR 1.07 (95% CI 0.99-1.15), p = 0.079), and performance of ECV > 7 days from ER onset (OR 2.99 (95% CI 1.01-8.87), p = 0.048) remained independently associated with ECV failure. During 1-year follow-up, the rate of LR was significantly higher among patients with failed ECV as compared to patients with successful ECV (hazard ratio (HR) 3.00 (95% CI, 1.79-5.03), p < 0.001). Patients with ECV performed > 7 days from ER onset had a significantly higher risk of developing LR as compared to patients with ECV performed within ≤ 7 days from ER onset (HR 1.73 (95% CI 1.15-2.62), p = 0.009). Performance of ECV > 7 days from ER onset (HR 1.76 (95% CI 1.16-2.67), p = 0.008) and failed ECV (HR 3.32 (95% CI 1.96-5.64), p < 0.001) remained independently associated with LR. CONCLUSIONS: A failed ECV and performance of ECV > 7 days from ER onset were independently associated with LR.

Feasibility of a novel algorithm for automated reconstruction of the left atrial anatomy based on intracardiac echocardiography.

BACKGROUND: Intracardiac echocardiography (ICE) is frequently used to guide electrophysiology procedures. The novel automated algorithm Cartosoundfam is a model-based algorithm which reconstructs a 3D anatomy of the left atrium (LA) based on a set of 2D intracardiac echocardiography (ICE) frames, without the need to manually annotate ultrasound (US) contours. OBJECTIVE: The aim of this study was to determine the feasibility of the Cartosoundfam module in routine clinical setting. METHODS: We included 16 patients undergoing LA mapping/catheter ablation. Two-dimensional US frames were acquired from the right atrium (RA) and the right ventricular outflow tract. The Cartosoundfam map was validated in two steps: (1) identification of anatomical structures (pulmonary veins [PV] and LA body and appendage) by alignment of the ablation catheter to the automated map; and (2) analysis of the automated lesion tags (Visitag) location in relation to the PV antrum of the Cartosoundfam map in nine patients with paroxysmal atrial fibrillation (AF) undergoing first time pulmonary vein isolation (PVI). RESULTS: Mean 2D US frames per patient were 29 ± 6 and acquisition time was 16 ± 4 min. All anatomical structures were correctly identified in all patients (step 1). In the step 2 validation, the median distance to the map was 2.0 (IQR: 2.4) mm and the majority of the Visitags were classified as satisfactory (69%) but all PV segments had some Visitags classified as unsatisfactory. CONCLUSION: The automated ICE-based algorithm correctly identified the LA anatomical structures in all patients with a 69% anatomical accuracy of the Visitags alignments to the PV antrum segments.

Color Variations in Left Atrial Appendage Occluders.

The authors stopped a case of left atrial appendage occlusion because of miscolored brownish devices. The investigation demonstrated that devices may show a range of colors from a typical blue to a brownish hue, depending on oxide layer thickness, and this does not appear to have any impact on the performance of the device. (Level of Difficulty: Intermediate.).

Cryoablation of atypical atrioventricular nodal reentry tachycardia.

AIM: Data on ablation for atypical recurrent atrioventricular nodal reentry tachycardia (AVNRT) and long-term follow-up are generally sparse. Furthermore, the rate of recurrence and safety of cryoablation for atypical AVNRT has not been established. We compared patients cryoablated for atypical AVNRT and typical AVNRT during long-term follow-up. METHODS: All patients (n = 2612) who underwent catheter ablation for AVNRT at the Karolinska University Hospital between January 2009 and August 2019 were analyzed. A total of 91 patients undergoing first-time cryoablation for atypical AVNRT were included. A control group with first-time cryoablation for typical AVNRT was matched in a 1:1 ratio. Patients were followed-up for recurrences for a median of 5.0 years (interquartile range: 3.1-7.5 years). RESULTS: After 5 years, AVNRT recurrence occurred in 10 patients (11.0%) in the atypical AVNRT group and in 8 patients (8.8%) in the typical AVNRT group (hazard ratio: 1.31 [95% confidence interval: 0.52-3.32]; p = 0.568). The duration of the index procedure was significantly longer for atypical compared to typical AVNRT ablation (132.1 ± 49.2 min vs. 110.1 ± 38.8 min; p = 0.001). Transient AV blocks occurred in a similar fashion in the atypical compared to typical group (11 [12.1%] vs. 4 [4.9%]; p = 0.103). However, no ablation induced persistent AV block developed in either group. CONCLUSION: Cryoablation for atypical AVNRT showed similar rate of recurrences and safety compared to typical AVNRT during long-term follow-up.

Low incidence of major complications after the first six hours post atrial fibrillation ablation: Is same-day discharge safe and feasible in most patients?

AIMS: This study evaluates the incidence of procedural complications related to catheter ablation of atrial fibrillation (AF) to assess the potential feasibility and safety of same-day discharge in a large cohort. METHODS: We performed an analysis of prospectively collected data of complications of all patients staying overnight after undergoing AF ablation between 2001 and 2020 at a tertiary center. Using medical records, we analyzed complications occurring intraprocedurally until 6 h postablation and between 6 h postablation and discharge the day after the ablation procedure. RESULTS: In 5414 AF ablations, we identified a total of 108 (2.0%) major complications occurring intraprocedural or before discharge. Most major complications occurred intraprocedurally or within 6 h after the procedure (n = 96, 1.8%). Twelve (0.2%) major complications occurred between 6 h Postablation and discharge. The most common of these major complications were congestive heart failure (n = 6) and transient ischemic attack (TIA, n = 4). During this time span, 61 (1.1%) minor complications occurred. Factors independently associated with major complications intraprocedurally and until discharge were body mass index (BMI) ≥ 30 kg/m2 (p = .009), significant valvular disease (p = .001), cardiomyopathy (p < .001), prior stroke or TIA (p = .014), first-time procedure versus repeat procedure (p = .013), cryoablation versus radiofrequency (p < .001), and procedure duration (p < .001). CONCLUSION: After AF ablation, very few complications occurred between 6 h postprocedure and discharge the next day. Therefore, same-day discharge is a safe option for a majority of patients.

Occupational physical activity is associated with risk of atrial fibrillation in both men and women: a population-based cohort study.

AIMS: Previous studies have found that excessive sport activities are associated with an increased risk of atrial fibrillation (AF). Whether occupational physical activity (OPA) increases the risk for AF is not well studied. We aimed to examine whether OPA influences the risk of AF. METHODS: 80,922 men and women, free from AF, completed in 1997 a questionnaire about their OPA at that time (baseline), and also retrospectively in 1997 their OPA at the age of 30 and 50 years. Participants were categorised into three groups (low, medium and high) based on OPA load. Participants were followed-up in the Swedish National Patient Register for ascertainment of AF. Cox proportional hazards regression models were used to estimate relative risks (RR) with 95% confidence intervals (CI), adjusted for potential confounders. RESULTS: 11,614 cases of AF were diagnosed during follow-up time of up to 17 years. We observed an increased risk of AF in relation to increased load of OPA regardless of age. Compared with men who reported a low load of OPA, the multivariable RR (95% CI) for men with a high load was 1.10 (1.03-1.17) at 30 years, 1.11 (1.04-1.17) at 50 years and 1.19 (1.10-1.29) at baseline. The results for women were similar with multivariable RR of 1.16 (1.06-1.27) at 30 years, 1.14 (1.05-1.24) at 50 years and 1.11 (0.99-1.24) at baseline. CONCLUSION: These findings suggest that high load of OPA previous in life may play a role in increasing the risk for AF in both men and women.

Sinus heart rate post pulmonary vein ablation and long-term risk of recurrences.

PURPOSE: Cather ablation is known to influence the autonomic nervous system. This study sought to investigate the association of sinus heart rate pre-/post-ablation and recurrences in patients with atrial fibrillation undergoing pulmonary vein isolation (PVI). METHODS: Between January 2012 and December 2017, data of 482 patients undergoing their first PVI were included. Sinus heart rate was recorded before (PRE), directly post-ablation (POST) and 3 months post-ablation (3 M). All patients were screened for atrial tachyarrhythmia recurrences during the one-year follow-up. RESULTS: In the total study cohort, the mean resting sinus heart rate at PRE [mean 57.9 bpm (95% CI 57.1-58.7 bpm)] increased by over 10 bpm to POST [mean 69.4 bpm (95% CI 68.5-70.3 bpm); p < 0.001] followed by a slight decrease at 3 M [mean 67.3 bpm (95% CI 66.4-68.2 bpm)] but still remaining higher compared to PRE (p < 0.001). This pattern was observed in patients with and without recurrences at POST and 3 M (both p < 0.001 compared to PRE). However, at 3 M the mean sinus heart rate was significantly lower in patients with compared to patients without recurrences (p = 0.031). In this regard, patients with a heart rate change < 11 bpm (PRE to 3 M) or, as an alternative parameter, patients with a heart rate < 60 bpm at 3 M had a significantly higher risk of recurrences compared to the remaining patients (Hazard ratio (HR) 1.82 (95% CI 1.32-2.49), p < 0.001 and HR 1.64 (95% CI 1.20-2.25), p = 0.002, respectively). CONCLUSION: Our study confirms the impact of PVI on cardiac autonomic function with a significant sinus heart rate increase post-ablation. Patients with a sinus heart rate change < 11 bpm (PRE to 3 M) are at higher risk for recurrences during one-year post-PVI.

Focal atrial tachycardia-the localization differences between men and women: A study of 487 consecutive patients.

OBJECTIVE: The preferential sites for focal atrial tachycardia (FAT) are mainly in the right atrium in both sexes. However, a limited number of studies have indicated that sex differences in the localization of FAT. This study investigated possible sex differences in the distribution of FAT in a large cohort of patients referred for ablation. METHODS: From 2004 to 2019, 487 patients (298 women) were referred to our institution for ablation of FAT. A standard electrophysiological study was conducted, and isoproterenol or atropine was given when needed. Conventional catheter mapping, electroanatomic contact mapping, and noncontact mapping were used to assess the origin of ectopic atrial tachycardia. RESULTS: Overall, 451 foci were successfully ablated in 436 patients (90%). Although the foci located along the crista terminalis were more common in women than in men (42% vs. 29%; p=0.023), the opposite were found in the foci located along the tricuspid annulus (5% vs. 11%; p=0.032) and the right atrial appendage (RAA) (1% vs. 3%; p=0.032). Other locations were similarly distributed in men and women. In addition, the presence of persistent FAT was more frequent in men than in women (22% vs. 5%; p<0.001). Finally, the difference in the induction pattern of FAT was also remarkable between sexes. CONCLUSION: The distribution of FAT in women and men is different. In addition, persistent FAT seems more often in men than in women. The different distribution, persistency, and induction pattern of FAT should be considered in the successful management of this type of tachycardia.