Atrial Arrhythmias Research Articles

HD grid versus circular mapping catheter for assessment of pulmonary vein (pv) reconnections

Abstract Background Traditionally, circular mapping catheters (CMC) have been considered superior to other designs for mapping pulmonary vein reconnections due to the circular shape of the PV ostium. The grid multipolar catheter produces higher definition maps potentially overcoming the disadvantage of being rectangular. Purpose We assessed the acute procedural results, comparing Grid versus CMC in the setting of PV re-isolation to understand if one was superior to the other. Methods In this multicentre randomised controlled trial, 169 patients (62% male; median age 66 years [22-83) underwent repeat ablation, between July 2021 and March 2023, for recurrent symptomatic atrial arrhythmias. We undertook two LA maps for patients, utilising the Grid and the CMC. Blinded maps were collected with both catheters, followed by randomisation to one map for analysis and ablation. The primary outcome was the radiofrequency time required to isolate the pulmonary veins. Secondary outcomes include LA mapping time and density for both catheters, ability to identify pulmonary vein sleeves and duration of the ablation procedure. Results 126 patients had PV reconnections. 66 patients (64% male; median age 65 years [22-83]) in the Grid arm and 60 patients (68% male; median age 65.5 years [31-83]) in the CMC arm. There was one pericardial effusion and one TIA. There was no significant difference (p=0.202) found in the RF time required to achieve PV isolation in both Grid (mean RF time 200 ± 232 secs) vs CMC (mean RF time 169 ± 298 secs) arms. There was no significant difference (p=0.407) found between LA mapping time for the CMC (mean 1047 ± 454 seconds) and the Grid (Median 1080 ± 440 seconds). There was no significant difference (p=0.411) found in the total procedure time for the CMC (mean 122.7 minutes) and the HD grid (130 minutes). There were significantly more (p<0.001) PV mapping points identified with the grid (mean 354±213 points) than the CMC (mean 234±154 points) arm. There was no significant difference in PV sleeve reconnections found (p=0.106) between the grid (120 PV sleeve reconnections with a mean 1.4±0.71 reconnections) and the CMC (98 PV sleeve reconnections with a mean 1.52±0.72 reconnections). Both maps were analysed to assess reconnections on opposing catheter arms. The grid identified 20 PV sleeve reconnections not visible on the CMC, whilst 9 were visible on the CMC and not the grid. Conclusion There was no significant difference found in RF time, mapping time and overall procedure time. The Grid identified more reconnections not seen with the CMC and had an overall improved mapping density suggesting that this configuration could be superior for LA mapping.

Performance of apple watch for detecting atrial fibrillation among a known atrial fibrillation population

Abstract Background Photoplethysmography (PPG) based consumer accessible devices with algorithms for irregular rhythm detection are gaining popularity as an opportunistic screening tool for atrial arrhythmias, and are FDA cleared for use in patients without a history of atrial fibrillation (AF). However, these devices are increasingly used for the management of AF, a purpose for which some algorithms are not intended. Purpose To compare the performance of the Apple Watch Irregular Rhythm Notification (IRN) with an implantable cardiac monitor (ICM) for the detection of atrial fibrillation (AF) in patients with known AF from the DEFINE AFib study. Methods Patients with known AF, a LINQ or LINQ II ICM, and an Apple Watch with PPG-based IRN activated were included in the analysis. ICM detected AF episodes served as the standard to which Apple Watch IRNs were compared. All AF episodes detected by the ICM device were manually adjudicated by two trained, independent reviewers with a third independent reviewer in situations of disagreement. Only AF episodes ≥60 minutes during a 75-minute window in which the Apple Watch was monitoring were included in accordance with the known Apple Watch algorithm detection parameters. To eliminate oversampling of ICM detected episodes compared to Apple Watch IRNs, 1,000 simulations of one randomly selected episode per subject was done to avoid single-subject bias. Results In total, 97 subjects were analyzed of which 42 had an AF episode ≥60 minutes. Applying the 75-minute window of Apple Watch monitoring to episodes ≥60 minutes, 20 subjects had qualifying, adjudicated ICM detected AF. These 20 subjects accounted for 481 qualifying AF episodes. Of the ICM detected episodes, 191 (40%) occurred while an Apple Watch was not being worn. In total, 11/20 (55%) subjects had an IRN generated by the Apple Watch. Adjudication of the ICM episodes resulted in 290 true positive AF episodes ≥60 minutes during a 75-minute window while the watch was actively monitoring, with 74 (26%) of those episodes triggering an IRN resulting in a per episode sensitivity of 24 ± 7% and PPV of 91 ± 4% (Figure 1A). The efficacy of Apple Watch to detect AF episodes of differing lengths was assessed for episodes between 1-6 hours, 6-12 hours, 12-24 hours, and > 24 hours with sensitivities of 19 ± 19%, 38 ± 8%, 32 ± 10%, and 31 ± 8%, respectively (Figure 1B). The Apple Watch generated an annualized false positive rate of 2.25 IRNs for every patient year of monitoring. At the subject level, Apple Watch had a sensitivity of 48%, specificity of 100%, PPV of 100%, and NPV of 71% (Figure 1A). Conclusions In patients with a history of AF, the Apple Watch IRN was most sensitive at the individual subject level while watch performance was lower by episode. The current IRN algorithm favors longer episode durations. The limited sensitivity, dependence on user wear-time, and reliance on long-durations of AF limit the use of Apple Watch for AF management.

Timing of early recurrence of atrial fibrillation during the blanking period after catheter ablation for persistent atrial fibrillation and implications for long-term success: a multicentre study

Abstract Background After catheter ablation (CA) for atrial fibrillation (AF), early recurrences of AF (ERAF) that occur within a 90-day post-ablation "blanking period" are considered to represent transient post-ablation pro-arrhythmia. Purpose To determine if the timing of early recurrence of AF during the traditional 90-day post-CA blanking period is associated with long-term AF recurrence after CA for persistent AF (PsAF). Methods We performed a multicentre retrospective study of patients undergoing first-time CA for PsAF between 2015-2018. All patients had undergone pre-CA DCCV. Incidences of ERAF during the post-CA blanking period were reviewed, and patients were categorised into three groups based on the timing of last episode of ERAF during the blanking period: (1) no ERAF (reference population); (2) last ERAF <30 days post-CA; (3) last ERAF 31-90 days post-CA. The primary outcome was long-term recurrence of atrial arrhythmia, i.e. time to first recurrence of atrial arrhythmia occurring beyond the first 90 days after CA. Patients who had ERAF and exited the blanking period in AF (i.e. those with immediate recurrence at 90 days) were excluded from this analysis. Results 331 patients were identified from five centres. 206 patients had no ERAF during follow-up, 124 patients had ERAF during the blanking period, and in one patient the presence of ERAF was not documented. Of the 124 patients experiencing ERAF during the 90-day post-CA blanking period, the timing of the last episode was known in 122 patients (Table 1). Of these, 58 patients exited the 90-day blanking period in AF and were excluded. Over median post-CA follow-up of 590 days, 147 patients (54%) experienced the primary outcome. Compared with Group 1 (no ERAF), ERAF within each of the time periods was associated with a statistically significant progressively increased risk of long-term recurrence (Group 2, last ERAF <30 days post-CA: hazard ratio [HR] 1.95 [95% CI 1.15-3.31]; Group 3, last ERAF 31-90 days post-CA: HR 4.86 [95% CI 2.13-11.08]; Figure 1). Conclusion ERAF during the traditional 90-day post-CA blanking period is associated with long-term AF recurrence, with later recurrence within the 90-day period conferring greater risk. Patients with ERAF during the blanking period may need to be considered for earlier repeat intervention where clinically appropriate.

Validation of diagnostic wearable ECG data from high-risk patients and integration into the atrial fibrillation catheter ablation pathway

Abstract Background Wearables like the Apple Watch (AW) offer non-invasive, long-term monitoring and patient-led, single-lead ECG recordings. Although validated for Atrial Fibrillation (AF) detection in the general population, the accuracy and clinical utility of the single-lead ECG recording feature for the diagnosis of AF has not been evaluated in patients at high risk of atrial arrhythmias.(1) An evaluation of the accuracy of the Wearable-derived labels is important to determine the feasibility of integrating AW-based remote monitoring into clinical pathways. Objective To evaluate the accuracy and data burden from AW-based, patient-led ECG monitoring in patients undergoing AF catheter ablation. Methods Patients referred for first-time AF catheter ablation to the Study Institution between January 2022 and March 2023 were invited to enrol in the AF Follow-up with Apple Watch (AFFU-AW) Trial. Patients randomised to the active arm of the study received 12 months of post-ablation follow-up using a loaned Apple Watch. Participants underwent an education session and were asked to perform daily ECGs; sending through any labelled as AF, inconclusive, or in the context of symptoms. The accuracy of the automated ECG labelling was determined against blinded, independent labelling by two experienced Electrophysiologists. Results 1093 remote transmissions were emailed in for evaluation from 52 patients to the Study team. This was a median of 6 [2, 17] per patient and a receiver burden of 2 [1, 4] ECGs per day. 475 were categorised by the AW as AF with a sensitivity of 0.71 and specificity of 0.96 compared to expert labelling. 342 (31%) were not categorised by the wearable, with an ‘inconclusive’ interpretation (161 [47%]) or ‘high heart rate’ (108 [32%]) as the most cited reasons. 178 (55%) of the uncategorised ECGs were subsequently overread as AF. Accompanying symptoms were reported with 324 (30%) ECGs, most commonly palpitations. Conclusion This is the first reported evaluation of the AF diagnostic feature based on AW ECG recordings as part of a remote patient rhythm surveillance pathway after catheter ablation. The high positive predictive value of ‘Sinus Rhythm’ and ‘AF’ labels and the high specificity of the ‘AF’ label are comparable to diagnostic algorithms in implantable loop recorders.(2) The source code to automate data curation and structured databasing of wearable ECGs has been made available for care providers to integrate the service into device monitoring workflows.(3)

Sex-specific prognostic implications of new-onset atrial fibrillation in patients treated with dual chamber pacemakers

Abstract Background Right ventricular pacing induces ventricular dyssynchrony, which over time may result in left ventricular dysfunction, increased left ventricular filling pressures, and ensuing left atrial dilatation, with increased risk of atrial arrhythmias. Atrial fibrillation (AF) prior to device implant is associated with worse prognosis, but the prognostic effects of new-onset AF during pacemaker treatment are less well described. Purpose To describe risk factors, incidence, and prognostic effects of new-onset AF after treatment is initiated with a dual chamber pacemaker. To evaluate mortality and risk of heart failure diagnosis or hospitalisation for heart failure in patients who develop AF, compared to those who do not develop AF. Methods All patients without pre-existing heart failure or atrial fibrillation, who received a dual chamber pacemaker at a large-volume tertiary care center during the period 2005–2020 were included. Data was crossmatched between the national pacemaker registry, the population registry and national disease registries. The primary outcome was 10-year mortality, and the secondary outcome was new-onset heart failure. Results 37127 patients were included in the study, of which 14760 (30%) were female. Median age was 76.4 years [interquartile range, IQR, 68.0–83.1] and the most common indication for pacemaker implant was AV block (57.7%), see Table 1. Overall, 10-year survival was higher for female patients, compared to male patients, p<0.0001 (see Kaplan-Meier curve in Figure 1A). Patients who developed new-onset AF had more comorbidities, were slightly older and a higher percentage were men. During follow-up 3661 (9.9%) developed atrial fibrillation within two years (9.1% of female and 10.3% of male patients, p<0.001), at a median of 291 [88–461] days after implant. In multivariable Cox regression analysis with new-onset AF as time dependent covariable and adjusted for clinically relevant covariables, AF was an independent predictor of higher all-cause mortality (HR 1.43 [1.37–1.49], p<0.0001). Risk factors for new-onset AF included increasing age, male sex, hypertension, malignancy, diabetes, chronic obstructive lung disease, chronic renal disease, and sick sinus syndrome indication (all p<0.01). In separate analyses for men and women, the risk factors and magnitude of odds ratios were the same. Conclusion In patients treated with dual chamber pacemakers due to bradycardia or AV block, development of new-onset AF within two years was associated with a higher 10-year mortality. The risk of developing AF was higher for men, but the negative prognostic effect was more pronounced for women.Figure 1A.-B. K-M survival curves

Early ablation leads to better outcome in patients < 55 years with persistent atrial fibrillation

The question of optimal timing for catheter ablation of atrial fibrillation (AF) to achieve best outcomes remains a crucial clinical issue. As AF occurs less frequently in younger patients, data regarding Diagnosis-to-Ablation Time (DAT) is especially limited in patients under the age of 55 years with persistent AF. We therefore analyzed the temporal relationship between initial AF presentation and timing of catheter ablation in this cohort. We conducted a retrospective single-centre study of patients ≤ 55 years with persistent AF who underwent first-time catheter ablation at our center. The cohort was divided into patients that underwent catheter ablation after diagnosis of persistent AF within a DAT of ≤ 12 months and patients with a DAT of > 12 months. A total of 101 patients (median age 51 years; female n = 19 (18.8%)) with persistent AF were included. Ablation was performed within 12 months (“early DAT”) in 51 patients and > 12 months (“late DAT”) in 50 patients. Pulmonary vein isolation was performed using high-power short-duration (HPSD) radiofrequency ablation. Median DAT was 5 months (1–12 months) in the early ablation group and 36 months (13–240 months) in the late ablation group. The median follow-up was 11.3 months (0.03–37.1 months). The rate of any atrial arrhythmia recurrence after a 30-day blanking period was significantly lower in the early DAT group (13/51 patients; 25.5%) as compared to the late DAT group (26/50 patients; 52.0%) (log rank test; p = 0.003). Catheter ablation performed > 12 months after the initial AF diagnosis was an independent predictor for the occurrence of any atrial arrythmia (OR: 2.58; (95%-CI: 1.32–5.07). Early first-time catheter ablation (DAT ≤ 12 months) in patients ≤ 55 years with persistent AF is associated with a significantly lower rate of arrhythmia recurrence.

Atrial cardiomyopathy resulting from loss of plakophilin-2 expression: Response to adrenergic stimulation and implications for the exercise response.

Atrial arrhythmias occur in 20-40% of patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) and are associated with an increased risk of sustained ventricular arrhythmias and inappropriate implantable cardioverter-defibrillator shocks. The pathophysiology of atrial arrhythmias in ARVC remains unclear. Most cases of gene-positive ARVC are linked to pathogenic variants in the desmosomal gene plakophilin-2 (PKP2). Here, we test the hypothesis that loss of PKP2 expression leads to pro-arrhythmic changes in atrial cardiomyocytes. Atrial cells/tissue were obtained from a cardiac-specific, tamoxifen-activated model of PKP2 deficiency (PKP2cKO). By contrast to PKP2cKO ventricular myocytes, PKP2cKO atrial cardiomyocytes presented no significant differences in intracellular calcium (Ca2+ i) transient dynamics, sarcoplasmic reticulum load or action potential morphology. PKP2cKO atrial cardiomyocytes showed elevated reactive oxygen species levels, increased frequency and amplitude of Ca2+ sparks, and increased diastolic [Ca2+]i compared to control; the latter two parameters were further increased by isoproterenol exposure and reversed by exposure to ryanodine receptor blocker dantrolene. We speculate that these isoproterenol-dependent effects may impact on the exercise-related atrial arrhythmia risk in ARVC patients. Despite absence of changes in Ca2+ i transient dynamics, PKP2cKO atrial cardiomyocytes showed enhanced sarcomere shortening and impaired sarcomere relaxation. Orthogonal transcriptomic analysis of human(GTEx) and PKP2cKO atrial tissue led to identification of 41 transcripts depending on PKP2 expression. Biochemical follow-up confirmed reduced abundance of sarcomeric protein myosin binding protein C, potentially playing a role in cellular shortening and relaxation changes observed. Our findings provide novel insights into the role of PKP2 in atrial myocardium with potential implications to therapeutic management of atrial fibrillation in patients with PKP2-related ARVC. KEY POINTS: Atrial arrhythmias occur in a large group of patients with arrhythmogenic right ventricular cardiomyopathy (ARVC), a cardiac disease mostly caused by pathogenic variants in the desmosomal gene plakophilin-2 (PKP2). Exercise is considered to be an independent risk factor for arrhythmias consequent to PKP2 deficiency. Weshow that loss of PKP2 expression affects cellular calcium handling and electrophysiology differently in left atrial vs. ventricular myocardium and causes extensive atrial fibrosis. PKP2-deficient atrial cardiomyocytes present increased spontaneous sarcoplasmic reticulum calcium release events, furtherenhancedby isoproterenol exposure and reversiblebya ryanodine receptor blocker(dantrolene). In addition, PKP2-deficient atrial myocytes exhibit impaired relaxation and enhanced sarcomere shortening, most probably related to reduced abundance of myosin binding protein C. We speculate that cellular effects reported upon isoproterenol impact on the exercise-related atrial arrhythmia risk in ARVC patients. We further propose that therapeutic approaches aimed at mitigating ventricular damage may be effective to treat the atrial disease in ARVC.

Left Atrial Low-Voltage Extent Predicts the Recurrence of Supraventricular Arrhythmias.

The incidence of left atrial (LA) supraventricular arrhythmias is increasing. Even after LA ablation, recurrence of these tachycardias is common. MRI studies show that LA cardiomyopathy is a significant risk factor for recurrence and correlates with low voltage areas detected via 3D electroanatomic mapping (EAM). There are limited data on the impact of low voltage extent detected by EAM on recurrence-free survival. Voltage thresholds defining low voltage vary across different studies. This study aims to investigate the impact of the extent of low voltage areas in the LA on recurrence-free survival and to assess whether defining low voltage areas using thresholds of 0.5, 0.4, or 0.3 mV offers better predictive performance. Patients with atrial arrhythmia who underwent LA EAM at Ulm University Heart Center between September 2018 and September 2022 were included from the ATRIUM registry. ROC analysis determined the voltage threshold for predicting recurrence-free survival. Kaplan-Meier and logistic regression models adjusted for patient variables were used to analyze recurrence-free survival. Of 1089 screened patients, 108 met the inclusion criteria. ROC analysis indicated that a 0.4 mV threshold for low voltage provided the best predictive performance. Logistic regression showed a 1.039-fold increase in recurrence risk per percent increase in LA low voltage area (odds ratio = 1.039, 95% CI 1.014-1.064). Low voltage extent in EAM correlates with 1-year recurrence rate after ablation of left atrial supraventricular arrhythmias. The threshold of 0.4 mV is the most suitable for predicting recurrences of those examined.

Arrhythmias in adult patients after Rastelli surgery: a single-centre experience.

Rastelli surgery is used for the correction of several CHDs. Although late-onset cardiac arrhythmias have emerged as a major complication after corrective surgeries, there is a paucity of data on arrhythmias after Rastelli surgery. This retrospective cohort study was conducted on patients who had undergone Rastelli surgery and have been followed at the adult CHD clinic at our hospital. A total of 55 patients (36.4% female, age 22.2 ± 6.4 years) were followed for a median period of 24.2 (20.6-31.0) years. Tachyarrhythmias occurred in 21 (38.4 %) patients (n = 15 for atrial tachycardia, 5 for ventricular tachycardia, and 1 for both atrial and ventricular tachycardia). Older age at surgery was significantly associated with the risk of tachyarrhythmias (P = 0.022). Bradyarrhythmia occurred in 12 (21.8%) patients and consisted of perioperative AV block (n = 5), late AV block (n = 1), and sinus node dysfunction (n = 6). Nine (16.4%) patients underwent catheter ablation. The mechanisms of atrial arrhythmias include cavotricuspid isthmus-dependent and surgical scar-dependent intra-atrial reentrant tachycardias. Among the three patients who underwent ablation for ventricular tachycardia, all circuits were dependent on the scar at the base of the right ventricle to pulmonary artery conduit. Median survival free from any event (arrhythmia, death, or heart failure) was 31.6 (28.1-35.1) years after Rastelli surgery. The prevalence of arrhythmias late after Rastelli surgery is substantial and increases in the second decade after surgery. Older age at surgery is associated with a higher prevalence of arrhythmias.

A preliminary investigation of the left atrial suspended cord and its significance as revealed by coronary CT angiography: an observational study with a systematic literature review

BackgroundThe occurrence of suspended cords of the left atrium (SCLA) is rare and has seldom been described. The purpose of this study was to summarize the cases of SCLA accidentally detected by coronary CT angiography (CCTA), describe their imaging features, conduct a preliminary analysis of their clinical significance, and review relevant literature.MethodsA total of 10,796 patients who underwent CCTA examinations from July 2020 to November 2021 were consecutively selected. The original and three-dimensional reconstruction images were reviewed to identify patients with SCLA. A control group was selected in a 1:2 ratio based on age, BMI, sex, and education level. The imaging characteristics and clinical data of the two groups were collected and compared. The case group was divided into two subgroups based on the starting and ending positions of the SCLA: Group 1 with the SCLA between the free wall and free wall, and Group 2 with the SCLA between the septum wall and free wall. The clinical features of these subgroups were compared. Furthermore, a review of literature on SCLA published in the past fifteen years that includes its clinical and imaging features was conducted.ResultsIn this study, a total of 35 patients were found to have SCLA, resulting in an incidence rate of approximately 0.32%. After excluding 1 patient for whom clinical features could not be obtained, the case group included a total of 18 males and 16 females, with a male-to-female ratio of 1:1 and a median age of 57.00 (52.00–64.00) years. It was found that 19 (55.88%) cases of SCLA were located near the right superior pulmonary vein ostia, while no SCLA was found near the left lower pulmonary vein orifice. A significant difference in the incidence of atrial arrhythmia between the two groups was observed (p = 0.009). Additionally, 3 patients (8.82%) in the SCLA group had a history of transient cerebral ischemic attack (TIA), which was significantly different from that in the control group (p = 0.035). The anteroposterior and transverse diameters of the left atrium were longer in the case group than in the control group (p < 0.05), but there was no significant change in left atrial volume. Subgroup analyses found no significant difference in the incidence of cerebral infarction, atrial arrhythmia, or other intracardiac structural malformations, although there was a significant difference in cord length (p = 0.013), with the length of SCLA in Group 1 and Group 2 being 2.64 ± 0.99 cm and 3.39 ± 0.68 cm, respectively. Notably, only 1 of these 34 patients was diagnosed based on echocardiography, whereas all cases were perfectly visualized using CCTA.ConclusionSCLA is rare. CCTA can accurately detect and depict this abnormal structure as compared to echocardiography. SCLA may be linked to a higher incidence of atrial arrhythmias or transient ischemic attacks. It is important for radiologists and cardiovascular experts to recognize this structure, and further investigation is necessary to determine its clinical significance.

Combined left atrial appendage occlusion and catheter ablation procedure for left atrial arrhythmias: A real-world, propensity-matched analysis.

Real-world studies comparing safety and efficacy of combined percutaneous left atrial appendage occlusion (LAAO) and catheter ablation (CA) to LAAO alone are limited. Patients from a large US hospital system undergoing combined LAAO and left-atrial CA from 8/2020 to 2/2024 were retrospectively analyzed and compared to a control group undergoing LAAO alone. Controls were identified using a 1:2 propensity score match based on LAAO device type (Watchman FLX vs. Amulet), CHA2D2-VASc and Hypertension, Abnormal renal/liver function, Stroke, Bleeding history or predisposition, Labile international normalized ratio [INR], Elderly, Drugs/alcohol (HAS-BLED) scores and compared for safety, sealing performance and clinical outcomes at 6 months. Patients were younger in the combined (n = 72) than in the control group (n = 144, 70.2 ± 7.3 vs. 76.7 ± 6.9 years, p < 0.001) but otherwise comparable with a mean CHA2D2-VASc score of 4.2 ± 1.1 and 4.4 ± 1.2 (p = 0.26) and HAS-BLED score of 2.2 ± 0.8 and 2.3 ± 0.7 (p = 0.34). Successful LAAO implantation rates were the same (95.8% vs. 95.8%, p = 0.99) with longer procedure times seen in the combined group (156.5 ± 53 vs. 56 ± 26 min, p < 0.001). Both major (1.4% vs. 2.1%, p = 0.72) and minor (27.8% vs. 19.4%, p = 0.17) in-hospital complications were similar between the combined and control group, respectively. At 45 days, presence of peri-device leak (18.3% vs. 30.4%, p = 0.07) and device related thrombosis (4.5% vs. 4.5%, p = 0.96) on transesophageal echocardiogram did not differ. Finally, all-cause mortality (0% vs. 1.4%, p = 0.99), thromboembolic (0% vs. 0%, p = 0.99) and bleeding (6.1% vs. 4.4%, p = 0.73) events during follow-up were comparable. This large, real-world analysis indicates comparable safety and efficiency of combined LAAO and CA when compared with LAAO alone.

Lesion monitoring parameters as predictors of atrial arrhythmia recurrence after catheter ablation in persistent AF: A DECAAF II sub-analysis.

The formation of transmural lesions is necessary for the ablation of persistent atrial fibrillation (prAF). Ablation index (AI) and generator impedance drop (ID) predict lesion size but their correlation with long-term outcomes in prAF is not known. Furthermore, we proposed a new parameter, efficacy ratio (ER) calculated as ID/AI, to gain indirect insight into the role of factors affecting ID but not considered by AI. We included ablations performed during the DECAAF II trial if they had uploaded lesion-by-lesion summary data and were performed with radiofrequency catheters on the CARTO system. Average patient-level parameters were calculated from all generated Vizitags. A total of 427 ablations met inclusion criteria and 166 utilized AI. Analyzed as continuous variables, ID and ER predicted long-term arrhythmia-free survival but not AI. The ideal cut-off for ID was ID ≥ 10.4 ohms and had a C-index of 0.55. It predicted reduced risk of arrhythmia: hazard ratio 0.56 [0.36-0.88], p = .013 (arrhythmia-free survival of 67% vs. 52%). Similarly, an ER of 1.7 ohms/100AI had a C-index of 0.58 and predicted reduced arrhythmia recurrence: HR0.39 [0.22-0.69], p = .001. ER < 1.7 ohms/100AI was related to just 32% arrhythmia-free survival. ER improved prognostication as compared to ID alone and identified a subset of low ID patients with even worse outcomes. Average ID was predictive of improved outcomes following ablation of prAF. The ratio of ID/AI (ER) was postulated as a measure to summarize the overall impact of factors not considered in the AI formula and provided improved prognostication.

Effectiveness of a Triple Antiarrhythmic Drug Strategy for Arrhythmia Recurrence after Persistent Atrial Fibrillation Ablation.

Treating recurrent atrial arrhythmias after persistent atrial fibrillation (PeAF) ablation is often challenging. This single-center, prospective study aimed to observe the effectiveness of different combinations of oral antiarrhythmic drugs (AADs) in reverting to sinus rhythm (SR) in patients with recurrent atrial arrhythmias after PeAF ablation. Forty-five patients who experienced recurrent atrial arrhythmias after PeAF ablation were included. Based on their medication regimens, patients were divided into two groups, with the study group being a triple-drug group (digoxin combined with amiodarone/ propafenone and β-blocker), and the control group being a non-triple-drug group. The rate of reversion to SR was significantly higher in the study group (n = 29) than in the control group (n = 16) at 3 weeks (34.48% vs. 0%, p<0.01) and 1 month (44.84% vs. 6.25%, p = 0.02) after initiating AADs. No patients with asymptomatic bradycardia were observed in either group. For patients with recurrent atrial arrhythmias after PeAF ablation, a regimen of low-dose digoxin combined with amiodarone/propafenone and β-blocker may effectively improve short-term reversion rates.

Safety of Magnetic Resonance Imaging in Patients with Cardiac Implantable Electronic Devices.

MRI (magnetic resonance imaging) represents the diagnostic image modality of choice in several conditions. With an increasing number of patients requiring MRI for diagnostic purposes, the issue of safety in patients with cardiac implantable electronic devices (CIED) undergoing this imaging modality will play an ever more important role. The purpose of this study was to assess the safety and device function following MRI in an unrestricted real-world cohort of patients with a wide array of cardiac devices. We conducted a retrospective single-center study including 1010 MRI studies conducted in adult patients (≥18 years) with an implanted CIED treated in the University Hospital of Munich (LMU) between July 2012 and March 2024. Patients with non-MR conditionally labeled leads, abandoned or epicardial leads, as well as lead fragments, were included for analysis. Across a total of 1010 MRIs (920 total MR-conditional device generators) performed in patients with an implanted CIED, there were no deaths, reports of discomfort, palpitations, heating, or ventricular arrythmias in the 24 h following MRI. Only 2/1010 MRIs were followed by a reported atrial arrhythmia within 24 h, both in patients with an MR-conditional pacemaker (PM) device without an abandoned lead. No significant changes in device function following MRI from baseline were observed across all included CIEDs. Lastly, no instances of severe malfunction, such as generator failure, loss of capture, electrical reset, or inappropriate inhibition of pacing, were found in post-MRI interrogation reports across all MRI studies. Based on the analysis of 1010 MRIs undergone by patients with CIEDs, following standardized device interrogation, manufacturer-advised device programming, monitoring of vital function, and manufacturer-advised reprogramming, MRI can be performed safely and without adverse events or changes in device function.

Effect of Pulmonary Vein Isolation with Left Atrial Wall Isolation Plus Selective CFAE Ablation in Patients with Persistent Atrial Fibrillation.

Pulmonary vein isolation (PVI) is a foundational treatment for persistent atrial fibrillation (PeAF), but the effectiveness of adding posterior wall isolation (PWI) and selective complex fractionated atrial electrogram (CFAE) ablation in the roof and anterior wall remains debated. The potential of these additional ablation techniques to improve long-term outcomes for PeAF patients is still uncertain. This retrospective study included 151 PeAF patients who underwent first-time catheter ablation at our center. The choice of ablation strategy was based on the operator's clinical judgment, taking into account the patient's specific condition and anatomical features. Patients were divided into two groups: the PVI group, which received PVI alone, and the modified PWI (MPWI) group, which received PVI along with additional PWI and selective CFAEs ablation in the roof and anterior wall. The primary endpoint was the absence of atrial arrhythmia lasting more than 30 s, without antiarrhythmic drugs, at 12 months. At the 12-month follow-up, 77.3% of the patients in the MPWI group and 52.1% of the patients in the PVI group remained in sinus rhythm without an atrial arrhythmia recurrence (p = 0.001). The BIC-based Cox regression analysis identified the ablation strategy and atrial fibrillation (AF) duration as independent predictors of recurrence across the cohort. It was found that MPWI significantly reduced the risk of recurrence, while a longer AF duration increased it. In the MPWI group, AF duration, left ventricular internal diameter in systole (LVIDs), and moderate or greater tricuspid regurgitation were independent predictors of recurrence. In the PVI group, only the left atrial low voltage area (LVA) index was a significant predictor. The addition of PWI and selective CFAE ablation to PVI significantly improves 12-month arrhythmia-free survival compared to PVI alone, demonstrating the superiority of this combined approach in improving long-term outcomes for patients with persistent AF.

Comprehensive vs. standard remote monitoring of cardiac resynchronization devices in heart failure patients: results of the ECOST-CRT study.

Integrating remote monitoring (RM) into existing healthcare practice for heart failure (HF) patients to improve clinical outcome remains challenging. The ECOST-CRT study compared the clinical outcome of a comprehensive RM scheme including a patient questionnaire capturing signs and symptoms of HF and notifications for HF specific parameters to traditional RM in patients with cardiac resynchronization therapy (CRT) devices. Patients were randomized 1:1 to standard daily RM (notification for technical parameters and ventricular arrhythmias; control group) or comprehensive RM (adding a monthly symptom questionnaire and notifications for biventricular pacing, premature ventricular contraction, atrial arrhythmias; active group). The primary endpoint was all-cause mortality or hospitalization for worsening HF (WHF). Six hundred fifty-two patients (70.4 ± 10.3 years, 73% men, left ventricular ejection fraction 29.1 ± 7.6%, 68% CRT-Defibrillators, 32% CRT-Pacemakers) were enrolled. The COVID-19 pandemic caused an early termination of the study, so the mean follow-up duration was 18 ± 8 months. No statistically significant difference in the primary endpoint was found between the groups [59 (18.3%) control vs. 77 (23.3%) active group; log-rank test P = 0.13]. Among the secondary endpoints, the MLHF questionnaire showed a larger share of patients with improvement of quality of life compared to baseline in the active group (78%) vs. control (61%; P = 0.03). The study does not support the notion that comprehensive RM, when compared to standard RM, in HF patients with CRT improves the clinical outcome of all-cause mortality or WHF hospitalizations. However, this study was underpowered due to an early termination and further trials are required. Clinical Trials.gov Identifier: NCT03012490.

Recurrent atrial flutter after radiofrequency ablation for atrial fibrillation in a patient with hypertrophic obstructive cardiomyopathy undergoing repetitive transcoronary ablation of septal hypertrophy

IntroductionWe described the clinical characteristics of a patient with hypertrophic obstructive cardiomyopathy (HOCM) who had undergone transcoronary ablation of septal hypertrophy (TASH) twice and developed atrial flutter after radiofrequency ablation for atrial fibrillation (AF) due to pulmonary vein reconnection. This case of HOCM is unique because of its complex complications and multiple complex atrial arrhythmias. The treatment of HOCM was successful and the postoperative follow-up results was good.Methods and resultsA 71-year-oldfemale, developed exertional dyspnea with palpitations 12 years ago, with a valid diagnosis of HOCM according to the echocardiography which showed an absolute increase in the interventricular septum thickness (22.8 mm). She underwent two rounds of TASH and only the second round was successful. During a visit due to recurrent palpitations, the patient was diagnosed with AF based on electrocardiographic examination. Circumferential pulmonary vein isolation (CPVI) was performed to treat AF. However, the recurrence of atrial flutter was detected on her electrocardiograms (ECGs) three years after the operation. Since the patient had an interstitial lung injury, there were relative contraindications for antiarrhythmic drugs. Due to restrictive use of antiarrhythmic drugs and continuous palpitation, the patient agreed to receive a second radiofrequency ablation. Left-sided macroreentrant circuits were identified via high-density mapping and successful ablation was performed at the isthmus.ConclusionsPerforming catheter ablation and TASH respectively in patients with HOCM associated with AF would be tricky. But taking such a comprehensive and respective clinical treatment would be beneficial to patients in the long term.

Characterization of atrial arrhythmias following mitral valve repair: Incidence and risk factors.

This study aims to investigate the occurrence, type and correlation of early and late atrial arrhythmias following mitral valve repair in patients with no preoperative history of atrial arrhythmias. Patients undergoing mitral valve (MV) repair for degenerative disease were included. Early and late postoperative electrocardiograms were evaluated for the incidence and type of atrial arrhythmia (atrial fibrillation [AF] or atrial tachycardia [AT]). The 192 patients were included. Early atrial arrhythmias occurred in 100/192 (52.1%) patients; AF in 61 (31.8%) patients, early AT in 15 (7.8%) and both in 24 (12.5%). In total 89% of patients were discharged in sinus rhythm. During a follow-up time of 7.3 years, 14 patients (7.3%) died and 49 (25.5%) patients developed late atrial arrhythmias. At 10 years, the cumulative incidence of any late atrial arrhythmia, with death as competing risk, was 64% (95% confidence interval [CI] = 55%-72%). On Fine-Gray model analysis, only early postoperative AF lasting >24 h was related to the development of late AF (hazard ratio 5.99, 95% CI = 1.78%-20.10%, p = .004). Early postoperative ATs were related to the development of late tachycardias, independent of their duration (<24 h hazard ratio 4.25, 95% CI = 1.89-9.57, p = .001 and >24 h hazard ratio 3.51, 95% CI = 1.65-7.46, p = .001). Early and late atrial arrhythmias were common after MV repair surgery. Only early postoperative AF lasting >24 h was a risk factor for the occurrence of late AF. Conversely, any postoperative AT was correlated to the development of late ATs.

Impact of Catheter Ablation on AtrialFibrillation Burden and Symptomsin Patients With HypertrophicCardiomyopathy.

Atrial fibrillation (AF) is more common in patients with hypertrophic cardiomyopathy (HCM) and is often highly symptomatic. The impact of catheter ablation (CA) may be under-reported when evaluated by long-term freedom from any atrial arrhythmia. This study aims to evaluate whether CA of AF in patients with HCM would significantly reduce AF burden and improve symptoms. A multicenter registry was established to enroll HCM patients with pre-existing cardiac implantable electronic devices undergoing CA of AF between 2017 and 2021. The first AF recurrence and burden 12months before and after CA were determined. Eighty-one HCM patients with cardiac implantable electronic devices underwent CA of AF. Patients were followed-up for a minimum of 1-year (35 [Q1-Q3 range: 23-50] months). AF was paroxysmal in 38 of 81 (46.9%) patients and burden pre-CA was 27.0% (Q1-Q3 range: 3.0% to 99.0%). Thirty-five (43.2%) patients had AF/atrial tachycardia recurrence within 12months. AF burden reduced after CA to 0.5% (Q1-Q3 range: 0.0% to 11.1%) (P=0.001); a 95% CI (range: 13.8% to 100%) relative reduction. European Hearth Rhythm Association class improved by 1.8 ± 1.3 classes (P<0.001). Of those with AF/atrial tachycardia recurrence, the reduction in AF burden was -33.7% (Q1-Q3 range: -88.9% to -13.8%) (P< 0.001) and 20 (57.1%) patients reported symptomatic improvement by≥1 European Hearth Rhythm Association class. AF burden reduction was associated with symptomatic improvement. (r=-0.67; P< 0.001) CONCLUSIONS: AF recurrence is common after CA in HCM patients, but this may under-represent the impact of CAinthis cohort. CA significantly reduced AF burden and improved symptoms. A comprehensive evaluation of AFburden,symptoms, and hard endpoints is needed to determine the utility of CA in this context.

Atrial flutter and sick sinus syndrome

BackgroundSick sinus syndrome (SSS) is a common condition resulting in reduced quality of life, syncope, and permanent pacemaker (PPM) implantation, but predictors have not been elucidated. Whereas atrial arrhythmias are frequently associated with SSS, we hypothesized that atrial flutter (AFL) would strongly predict SSS, given shared relationships with right atrial and particularly crista terminalis fibrosis. ObjectiveThe study aimed to assess the impact of AFL on the occurrence of SSS and associated syncope and PPM implantation. MethodsHealth care databases were used to identify adults aged ≥18 years receiving hospital-based care in California in 2005–2019. International Classification of Diseases codes were used to identify diagnoses and procedures. Patients were classified on the basis of the presence of AFL and atrial fibrillation (AF). Cox proportional hazards models adjusting for demographics and comorbidities were employed. ResultsWe included 29,357,609 individuals (54% female; mean age, 46 years), 101,243 with AFL alone, 1,674,680 with AF alone, and 284,547 with AF and AFL. After adjustment for age, sex, race and ethnicity, and comorbidities, AF, AFL, and both arrhythmias were each associated with increased risk of SSS and associated syncope and PPM implantation (all P < .001). In the population with AF, an additional AFL diagnosis conferred a higher risk for development of SSS (hazard ratio [HR],1.62; 95% confidence interval, 1.59–1.64), syncope (HR, 1.63; 1.54–1.72), and PPM implantation (HR, 1.74; 1.70–1.79). ConclusionAFL is associated with an increased risk of incident SSS and its adverse consequences, especially in patients with coexisting AF. AFL may be useful for risk stratification strategies to predict, to prevent, and to treat SSS.