Cardiac implantable electronic devices and bloodstream infections: management and outcomes.

BACKGROUND AND AIMS: Bloodstream infection (BSI) of any cause may lead to device infection in cardiac implantable electronic device (CIED) patients. Aiming for a better understanding of the diagnostic approach, treatment, and outcome, patients with an implantable cardioverter defibrillator (ICD) and cardiac resynchronization therapy and defibrillator (CRT-D) hospitalized with BSI were investigated. METHODS: This is a single-centre, retrospective, cohort analysis including consecutive ICD/CRT-D patients implanted between 2012 and 2021. These patients were screened against a list of all hospitalized patients having positive blood cultures consistent with diagnosed infection in any department of a local public hospital. RESULTS: The total cohort consisted of 515 patients. Over a median follow-up of 59 months (interquartile range 31-87 months), there were 47 BSI episodes in 36 patients. The majority of patients with BSI (92%) was admitted to non-cardiology units, and in 25 episodes (53%), no cardiac imaging was performed. Nearly all patients (85%) were treated with short-term antibiotics, whereas chronic antibiotic suppression therapy (n = 4) and system extraction (n = 3) were less frequent. Patients with BSI had a nearly seven-fold higher rate (hazard ratio 6.7, 95% confidence interval 3.9-11.2; P < .001) of all-cause mortality. CONCLUSIONS: Diagnostic workup of defibrillator patients with BSI admitted to a non-cardiology unit is often insufficient to characterize lead-related endocarditis. The high mortality rate in these patients with BSI may relate to underdiagnosis and consequently late/absence of system removal. Efforts to increase an interdisciplinary approach and greater use of cardiac imaging are necessary for timely diagnosis and adequate treatment.

Implantable loop recorders in patients with Brugada syndrome: the BruLoop study.

BACKGROUND AND AIMS: Available data on continuous rhythm monitoring by implantable loop recorders (ILRs) in patients with Brugada syndrome (BrS) are scarce. The aim of this multi-centre study was to evaluate the diagnostic yield and clinical implication of a continuous rhythm monitoring strategy by ILRs in a large cohort of BrS patients and to assess the precise arrhythmic cause of syncopal episodes. METHODS: A total of 370 patients with BrS and ILRs (mean age 43.5 ± 15.9, 33.8% female, 74.1% symptomatic) from 18 international centers were included. Patients were followed with continuous rhythm monitoring for a median follow-up of 3 years. RESULTS: During follow-up, an arrhythmic event was recorded in 30.7% of symptomatic patients [18.6% atrial arrhythmias (AAs), 10.2% bradyarrhythmias (BAs), and 7.3% ventricular arrhythmias (VAs)]. In patients with recurrent syncope, the aetiology was arrhythmic in 22.4% (59.3% BAs, 25.0% VAs, and 15.6% AAs). The ILR led to drug therapy initiation in 11.4%, ablation procedure in 10.9%, implantation of a pacemaker in 2.5%, and a cardioverter-defibrillator in 8%. At multivariate analysis, the presence of symptoms [hazard ratio (HR) 2.5, P = .001] and age >50 years (HR 1.7, P = .016) were independent predictors of arrhythmic events, while inducibility of ventricular fibrillation at the electrophysiological study (HR 9.0, P < .001) was a predictor of VAs. CONCLUSIONS: ILR detects arrhythmic events in nearly 30% of symptomatic BrS patients, leading to appropriate therapy in 70% of them. The most commonly detected arrhythmias are AAs and BAs, while VAs are detected only in 7% of cases. Symptom status can be used to guide ILR implantation.

Left ventricular functional recovery after atrial fibrillation catheter ablation in heart failure: a prediction model.

AIMS: Management of patients with atrial fibrillation (AF) and concomitant heart failure (HF) remains complex. The Antwerp score, based on four parameters [QRS >120 ms (2 points), known aetiology (2 points), paroxysmal AF (1 point), severe atrial dilation (1 point)] adequately estimated the probability of left ventricular ejection fraction (LVEF) recovery after AF ablation in a single-centre cohort. The present study aims to externally validate this prediction model in a large European multi-centre cohort. METHODS AND RESULTS: A total of 605 patients (61.1 ± 9.4 years, 23.8% females, 79.8% with persistent AF) with HF and impaired LVEF (<50%) undergoing AF ablation in 8 European centres were retrospectively identified. According to the LVEF changes at 12-month echocardiography, 427 (70%) patients fulfilled the '2021 Universal Definition of HF' criteria for LVEF recovery and were defined as 'responders'. External validation of the score yielded good discrimination and calibration {area under the curve 0.86 [95% confidence interval (CI) 0.82-0.89], P < .001; Hosmer-Lemeshow P = .29}. Patients with a score < 2 had a 93% probability of LVEF recovery as opposed to only 24% in patients with a score > 3. Responders experienced more often positive ventricular remodelling [odds ratio (OR) 8.91, 95% CI 4.45-17.84, P < .001], fewer HF hospitalizations (OR 0.09, 95% CI 0.05-0.18, P < .001) and lower mortality (OR 0.11, 95% CI 0.04-0.31, P < .001). CONCLUSION: In this multi-centre study, a simple four-parameter score predicted LVEF recovery after AF ablation in patients with HF and discriminated clinical outcomes. These findings support the use of the Antwerp score to standardize shared decision-making regarding AF ablation referral in future clinical studies.

Microelectrode voltage mapping for substrate assessment in catheter ablation of ventricular tachycardia: A dual-center experience.

INTRODUCTION: The assessment of the ventricular myocardial substrate critically depends on the size of mapping electrodes, their orientation with respect to wavefront propagation, and interelectrode distance. We conducted a dual-center study to evaluate the impact of microelectrode mapping in patients undergoing catheter ablation (CA) of ventricular tachycardia (VT). METHODS: We included 21 consecutive patients (median age, 68 [12], 95% male) with structural heart disease undergoing CA for electrical storm (n = 14) or recurrent VT (n = 7) using the QDOT Micro catheter and a multipolar catheter (PentaRay, n = 9). The associations of peak-to-peak maximum standard bipolar (BVc ) and minibipolar (PentaRay, BVp ) with microbipolar (BVµMax ) voltages were respectively tested in sinus rhythm with mixed effect models. Furthermore, we compared the features of standard bipolar (BE) and microbipolar (µBE) electrograms in sinus rhythm at sites of termination with radiofrequency energy. RESULTS: BVµMax was moderately associated with both BVc (ß = .85, p < .01) and BVp (ß = .56, p < .01). BVµMax was 0.98 (95% CI: 0.93-1.04, p < .01) mV larger than corresponding BVc , and 0.27 (95% CI: 0.16-0.37, p < .01) mV larger than matching BVp in sinus rhythm, with higher percentage differences in low voltage regions, leading to smaller endocardial dense scar (2.3 [2.7] vs. 12.1 [17] cm2 , p < .01) and border zone (3.2 [7.4] vs. 4.8 [20.1] cm2 , p = .03) regions in microbipolar maps compared to standard bipolar maps. Late potentials areas were nonsignificantly greater in microelectrode maps, compared to standard electrode maps. At sites of VT termination (n = 14), µBE were of higher amplitude (0.9 [0.8] vs. 0.4 [0.2] mV, p < .01), longer duration (117 [66] vs. 74 [38] ms, p < .01), and with greater number of peaks (4 [2] vs. 2 [1], p < .01) in sinus rhythm compared to BE. CONCLUSION: microelectrode mapping is more sensitive than standard bipolar mapping in the identification of viable myocytes in SR, and may facilitate recognition of targets for CA.

Identification of Brugada syndrome based on P-wave features: an artificial intelligence-based approach.

AIMS: Brugada syndrome (BrS) is an inherited disease associated with an increased risk of ventricular arrhythmias. Recent studies have reported the presence of an altered atrial phenotype characterized by abnormal P-wave parameters. The aim of this study was to identify BrS based exclusively on P-wave features through an artificial intelligence (AI)-based model. METHODS AND RESULTS: Continuous 5 min 12-lead ECG recordings were obtained in sinus rhythm from (i) patients with spontaneous or ajmaline-induced BrS and no history of AF and (ii) subjects with suspected BrS and negative ajmaline challenge. The recorded ECG signals were processed and divided into epochs of 15 s each. Within these epochs, P-waves were first identified and then averaged. From the averaged P-waves, a total of 67 different features considered relevant to the classification task were extracted. These features were then used to train nine different AI-based supervised classifiers. A total of 2228 averaged P-wave observations, resulting from the analysis of 33 420 P-waves, were obtained from 123 patients (79 BrS+ and 44 BrS-). Averaged P-waves were divided using a patient-wise split, allocating 80% for training and 20% for testing, ensuring data integrity and reducing biases in AI-based model training. The BrS+ patients presented with longer P-wave duration (136 ms vs. 124 ms, P < 0.001) and higher terminal force in lead V1 (2.5 au vs. 1.7 au, P < 0.01) compared with BrS- subjects. Among classifiers, AdaBoost model had the highest values of performance for all the considered metrics, reaching an accuracy of over 81% (sensitivity 86%, specificity 73%). CONCLUSION: An AI machine-learning model is able to identify patients with BrS based only on P-wave characteristics. These findings confirm the presence of an atrial hallmark and open new horizons for AI-guided BrS diagnosis.

Dynamic changes of left atrial substrate over time following pulmonary vein isolation: the Progress-AF study.

AIMS: Little is known about dynamic changes of the left atrial (LA) substrate over time in patients with atrial fibrillation (AF). This study aims to evaluate substrate changes following pulmonary vein isolation (PVI). METHODS AND RESULTS: In our prospective observational study, consecutive patients undergoing first PVI-only and redo ablation were included. High-density maps of the two procedures were compared. Progression or regression was diagnosed if a significant concordant decrease or increase in bipolar voltages in ≥2 segments was observed, respectively. In 28 patients (61.2 ± 9.5 years, 39% female, 53.5% persistent AF), 111.013 voltage points from 56 high-density LA maps (1.982 points/patient) were analysed. Comparing the high-density maps of the first and second procedures, in the progression group (17 patients, 61%), there was a decrease in global (-35%, P < 0.001) and all regional voltages. In the regression group (11 patients, 39%), there was an increase in global (+43%, P < 0.001) and regional voltages. Comparing the progression with the regression group, the area of low-voltage zone (LVZ) increased (+3.5 vs. -4.5 cm2, P < 0.001) and LA activation time prolonged (+8.0 vs. -9.1 ms, P = 0.005). Baseline clinical parameters did not predict progression or regression. In patients with substrate progression, pulmonary veins (PVs) were more frequently isolated (P = 0.02) and the AF pattern at recurrence was more frequently persistent (P = 0.005). CONCLUSION: Our study describes bidirectional dynamic properties of the LA substrate with concordant either progressive or regressive changes. Regression occurs with reduced AF burden after the first procedure, while progression is associated with persistent AF recurrence despite durable PV isolation. The dynamic nature of LA substrate poses questions about LVZ-based ablation strategies.

Diagnostic Yield of Electroanatomic Voltage Mapping in Guiding Endomyocardial Biopsies.

BACKGROUND: Electroanatomic voltage mapping (EVM) is a promising modality for guiding endomyocardial biopsies (EMBs). However, few data support its feasibility and safety. We now report the largest cohort of patients undergoing EVM-guided EMBs to show its diagnostic yield and to compare it with a cardiac magnetic resonance (CMR)-guided approach. METHODS: We included 162 consecutive patients undergoing EMB at our institution from 2010 to 2019. EMB was performed in pathological areas identified at EVM and CMR. CMR and EVM sensitivity and specificity regarding the identification of pathological substrates of myocardium were evaluated according to EMB results. RESULTS: Preoperative CMR showed late gadolinium enhancement in 70% of the patients, whereas EVM identified areas of low voltage in 61%. Right (73%), left (19%), or both ventricles (8%) underwent sampling. EVM proved to have sensitivity similar to CMR (74% versus 77%), with specificity being 70% and 47%, respectively. In 12 patients with EMB-proven cardiomyopathy, EVM identified pathological areas that had been undetected at CMR evaluation. Sensitivity of pooled EVM and CMR was as high as 95%. EMB analysis allowed us to reach a new diagnosis, different from the suspected clinical diagnosis, in 39% of patients. The complications rate was low, mostly related to vascular access, with no patients requiring urgent management. CONCLUSIONS: EVM proved to be a promising tool for targeted EMB because of its sensitivity and specificity for identification of myocardial pathological substrates. EVM was demonstrated to have accuracy similar to CMR. EVM and CMR together conferred a positive predictive value of 89% on EMB.

Myocardial Inflammation, Sports Practice, and Sudden Cardiac Death: 2021 Update.

Myocardial inflammation is an important cause of cardiovascular morbidity and sudden cardiac death in athletes. The relationship between sports practice and myocardial inflammation is complex, and recent data from studies concerning cardiac magnetic resonance imaging and endomyocardial biopsy have substantially added to our understanding of the challenges encountered in the comprehensive care of athletes with myocarditis or inflammatory cardiomyopathy (ICM). In this review, we provide an overview of the current knowledge on the epidemiology, pathophysiology, diagnosis, and treatment of myocarditis, ICM, and myopericarditis/perimyocarditis in athletes, with a special emphasis on arrhythmias, patient-tailored therapies, and sports eligibility issues.

Sports Activity and Arrhythmic Risk in Cardiomyopathies and Channelopathies: A Critical Review of European Guidelines on Sports Cardiology in Patients with Cardiovascular Diseases.

The prediction and prevention of sudden cardiac death is the philosopher's stone of clinical cardiac electrophysiology. Sports can act as triggers of fatal arrhythmias and therefore it is essential to promptly frame the athlete at risk and to carefully evaluate the suitability for both competitive and recreational sports activity. A history of syncope or palpitations, the presence of premature ventricular complexes or more complex arrhythmias, a reduced left ventricular systolic function, or the presence of known or familiar heart disease should prompt a thorough evaluation with second level examinations. In this regard, cardiac magnetic resonance and electrophysiological study play important roles in the diagnostic work-up. The role of genetics is increasing both in cardiomyopathies and in channelopathies, and a careful evaluation must be focused on genotype positive/phenotype negative subjects. In addition to being a trigger for fatal arrhythmias in certain cardiomyopathies, sports also play a role in the progression of the disease itself, especially in the case arrhythmogenic right ventricular cardiomyopathy. In this paper, we review the latest European guidelines on sport cardiology in patients with cardiovascular diseases, focusing on arrhythmic risk stratification and the management of cardiomyopathies and channelopathies.

Third- versus Second-Generation Stent Graft for Endovascular Aneurysm Repair: A Device-Specific Analysis.

PURPOSE: Our purpose is to analyze the outcomes of endovascular aneurysm repair (EVAR) in patients treated with Excluder endograft (W.L. Gore and Associate, Flagstaff, AZ), comparing second generation, featuring SIM-PULL delivery system (ExSP) and third generation, featuring C3 (ExC3), concerning intraprocedural data and long-term outcomes. METHODS: In our single-center, comparative study, we retrospectively analyzed all patients undergoing elective EVAR with Excluder from May 2008 to December 2015. This cohort was firstly divided according to the design of the endograft used, and then, two subgroups of complex procedures were identified according to International Standards. Preliminary end points were early- and mid-term outcomes. Primary end point was procedural data (i.e., procedural and fluoroscopy time, radiation dose (DAP), and contrast medium amount). RESULTS: The study included 64 patients (24 ExSP and 40 ExC3) with a mean follow-up of 31.6 ± 22.9 months. Patients in ExC3 group had significantly more risk factors (past or present history of smoking, P = 0.019), comorbidities (chronic heart failure and chronic kidney disease, both P = 0.032), as well as a more unfavorable anatomy (neck angulation, P = 0.035). Concerning preliminary outcome, no significant between-group difference was noted. As for intraoperative data, procedure duration was significantly shorter: 120 vs. 151 min (P = 0.002) in the overall population and 129 vs. 173 min (P = 0.004) in complex cases. A significant reduction was also found in fluoroscopy time and radiation exposure: 24,084 vs. 32,548 cGy/cm2 (P = 0.020) in the overall population and 26,770 vs. 41,104 cGy/cm2 (P = 0.003) in complex cases. No significant difference was found for contrast volume. CONCLUSIONS: The study shows that new C3 excluder enables to reduce radiation exposure and procedural time compared to the previous device. C3 excluder results are comparable to those of the previous device in spite of more comorbidities and complex anatomy of the treated patients. Further studies are needed to assess device performance on longer-term follow-up.

Impact of comorbidity on complication rates and life expectancy in patients with a leadless pacemaker.

BACKGROUND: Knowledge about impact of age and comorbidities on outcome in patients with leadless pacemakers (LPM) is limited. OBJECTIVES: To analyse outcome in LPM patients according to age and comorbidities. METHODS: This Swiss, multi-centre, retrospective analysis includes all patients with LPM implanted between 2015 and 2022. Charlson-Comorbidity-Index (CCI) was determined and patients were divided into a low- (CCI ≤ 5) and high-comorbidity (CCI > 5) group. Peri-procedural complications, in-hospital death, and all-cause mortalities were assessed. Finally, all-cause mortality according to three groups (CCI ≤ 3, 4-5, >5) was compared to age and sex-adjusted mortality in the general Swiss population. RESULTS: 863 patients (median age 81 years, 65% male, 42% with CCI > 5) were included. Peri-procedural/long-term complication rates did not differ between the low- vs. high-comorbidity groups (2.6% vs. 1.7%, p = 0.48 and 1.2% vs. 2.8%, p = 0.12, respectively). In-hospital (3.6% vs. 0.6%, p = 0.002) and all-cause mortality (HR 2.9, 95%CI 2.2-3.8, p < 0.001) were significantly higher in the high-comorbidity group resulting in a three-year mortality of 58% (95%CI 51-65%) vs. 22% (95%CI 17-27%) in the low-comorbidity group. In patients with a CCI ≤ 3, all-cause mortality was comparable to the age- and sex-adjusted mortality of the general Swiss population. CONCLUSIONS: In elderly patients with high comorbidity, LPM implantation was not associated with increased peri-procedural/long-term complications. All-cause mortality in LPM patients with a CCI ≤ 3 was comparable to age- and sex-adjusted mortality in the general Swiss population. Despite a relatively high three-year mortality due to competing risk factors, LPM implantation is safe, even in elderly patients with high comorbidity. CONDENSED ABSTRACT: In this Swiss, multi-centre, retrospective cohort analysis, 863 patients implanted with a leadless pacemaker were included and divided into a high-comorbidity (with a CCI > 5) and low-comorbidity (with a CCI ≤ 5) group. There was no between group difference in terms of implantation outcomes and peri-operative or long-term complications. Furthermore, all-cause mortality during follow-up in patients with a CCI ≤ 3 was comparable to age- and sex-adjusted mortality in the general Swiss population. These data indicate that LPM implantation is a safe procedure, even in elderly patients with high comorbidity.

Characterization of patients with extensive left atrial myopathy referred for atrial fibrillation ablation: incidence, predictors, and outcomes.

BACKGROUND: Although atrial fibrosis has a relevant impact on ablation success rate, experimental studies have reported that extensive fibrosis may be accompanied by a reduced burden secondary to a prominent depression of atrial excitability. OBJECTIVES: We aimed to identify clinical and echocardiographic factors associated with extensive left atrial myopathy (ELAM), to analyze the predictive ability of established scores (AF score, APPLE, and DR-FLASH) and assess outcomes in terms of AF recurrence, left atrial flutter, and post-procedural heart failure admissions. METHODS: A total of 950 consecutive patients undergoing the first AF ablation were included. A 3D electroanatomical mapping system (CARTO3, Biosense Webster) was created using a multipolar mapping catheter (PentaRay, Biosense Webster). ELAM was defined as ≥ 50% low voltage area. A subanalysis with four groups was also created (< 10%; 10-20%; 10-20%; and > 30%). Logistic regressions, Cox proportional hazards models, and log-rank test were used to test the predictors independently associated with the presence of ELAM and AF recurrence. The model was prospectively validated in a cohort of 150 patients obtaining an excellent ability for prediction AUC 0.90 (CI 95% 0.84-0.96). RESULTS: Overall, 78 (8.42%) presented ELAM. Age, female sex, persistent AF, first-degree AV block, and E/e' were significant predictors. The model incorporating these factors outperformed the existing scores (AUC = 0.87). During a mean follow-up of 20 months (IQR 9 to 36), patients with ELAM presented a higher rate of AF recurrence (42.02% vs 26.01%, p = 0.030), left atrial flutter (26.03% vs 8.02%, p < 0.001), and post-procedural heart failure admissions (12.01% vs 0.61%, p < 0.001) than non-ELAM patients. CONCLUSIONS: This study reveals the incidence and clinical factors associated with ELAM in AF, highlighting age, female, persistent AF, first-degree AV block, and E/e'. Importantly, the presence of ELAM is associated with poorer outcomes in terms of recurrence and HF admission.

Continuous Rhythm Monitoring With Implanted Loop Recorders in Children and Adolescents With Brugada Syndrome.

BACKGROUND: Young (<18 years of age) patients with Brugada syndrome (BrS) are often under-represented in BrS studies and their management, especially related to syncopal episodes, remains unclear. OBJECTIVES: This study sought to describe the arrhythmia prevalence among young patients with BrS undergoing continuous rhythm monitoring by implantable loop recorder (ILR) and to assess the etiology behind syncope of undetermined origin. METHODS: A total of 147 patients with BrS with ILR were enrolled in 12 international centers and divided into pediatric (age <12 years; n = 77, 52%) and adolescents (age 13-18 years; n = 70, 48%). RESULTS: Mean age was 11.3 years, 53 patients (36.1%) were female, and 31 (21.1%) had spontaneous type 1 electrocardiograms. Over a median follow-up of 3.6 years (Q1-Q3: 1.6-4.8 years), an arrhythmic event was recorded in 33 patients (22.4%), mainly of nonventricular origin: 15 atrial (10.2%) and 16 bradyarrhythmic events (10.9%). Ventricular arrhythmias occurred in 4 patients, all with spontaneous BrS, and were fever-related in one-half. Among all patients with recurrence of syncope during follow-up, true arrhythmic syncope was documented in 5 (17.8%), and it was due to bradyarrhythmias or atrial arrhythmias in 3 cases (60%). CONCLUSIONS: Continuous rhythm monitoring with ILRs in young patients with BrS detects a broad range of arrhythmias. Ventricular arrhythmias occur predominantly in patients with spontaneous type 1 electrocardiograms and during fever. Despite the young age, bradyarrhythmias and atrial arrhythmias are frequent and represent the cause of arrhythmic syncope in 60% of patients. Young patients with BrS with syncope of undetermined origin may benefit from ILR implant.

Atrial fibrillation cycle-length (AF-CL) inside the pulmonary veins predicts paroxysmal AF ablation success- the INDUCE-AF study.

BACKGROUND: A novel method to measure atrial fibrillation cycle length (AF-CL) was recently described, based on the average of 10 consecutive signals (FARS10). FARS10 accurately identified pulmonary vein isolation (PVI)-responders among patients with persistent AF. Whether this method is applicable to patients with paroxysmal AF is unknown. OBJECTIVE: The aim of this study is to evaluate the prognostic value of FARS10 measurements in patients with paroxysmal AF. METHODS AND RESULTS: We enrolled paroxysmal AF patients undergoing PVI in a prospective multicenter study. After AF induction with a standardized protocol, the AF-CL was measured using FARS-10 method. The primary endpoint was AF/AT-recurrence. One-hundred and four patients were included (61 ± 14 years, 25% females). After a mean follow-up of 12 ± 4 months, AF/AT recurrence rate was 20%. The fastest PV CL (fPV-CL) was independently associated with the primary endpoint at multivariate analysis (HR 1.02, p < 0.001). Every 10 ms increase in fPV-CL, AF recurrences increased by 20%. The value of 160 ms was found to be the optimal cut-off (specificity 81%, sensitivity 76%). Patients with fPV-CL < 160 ms experienced lower AF recurrences as compared to patients with fPV-CL > 160 ms (8% vs. 32% at 1 year; HR = 0.17, p < 0.001). Progression to persistent AF was observed in 13% of patients with fPV-CL > 160 ms. CONCLUSION: fPV-CL measured with the FARS-10 method accurately predicts PVI success in paroxysmal AF patients undergoing PVI. Patients with slow PV activity (fPV-CL > 160 ms) experience higher AF recurrence rate after PVI and more frequent progression to persistent AF. In 104 patients with paroxysmal atrial fibrillation (AF) undergoing AF ablation, AF was induced at the beginning of the procedure. Pulmonary vein activity was measured using FARS10 measurement (10 consecutive fastest atrial repetitive similar morphology signals). The value of 160 ms was found to be the best cut-off to discriminate outcomes. At 1-year follow-up, patients with fast veins (< 160 ms) experienced significantly fewer AF recurrences as compared to patients with slow veins (> 160 ms). PV activity measured with FARS10 method accurately discriminates pulmonary vein isolation responders, in patients with paroxysmal AF. ABBREVIATIONS: AF atrial fibrillation, AT atrial tachycardia, CL cycle length, FARS10: 10 consecutive fastest atrial repetitive similar morphology signal, fPV fastest pulmonary vein, HR hazard ratio, ms milliseconds.

Anterior mitral line in patients with persistent atrial fibrillation and anterior scar: A multicenter matched comparison-The MiLine study.

BACKGROUND: The benefit of an anterior mitral line (AML) in patients with persistent atrial fibrillation (AF) and anterior atrial scar undergoing ablation has never been investigated. OBJECTIVE: The purpose of this study was to evaluate the outcomes of AML in addition to standard treatment compared to standard treatment alone (no AML) in this subset of patients. METHODS: Patients with persistent AF and anterior low-voltage zone (LVZ) treated with AML in 3 centers were retrospectively enrolled. The patients were matched in 1:1 fashion with patients having persistent AF and anterior LVZ who underwent conventional ablation in the same centers. Matching parameters were age, LVZ burden, and repeated ablation. Primary endpoint was AF/atrial tachycardia (AT) recurrence. RESULTS: One hundred eight-six patients (age 66 ± 9 years; 34% women) were selected and divided into 2 matched groups. Bidirectional conduction block was achieved in 95% of AML. After median follow-up of 2 years, AF/AT recurrence occurred in 29% of the patients in the AML group vs 48% in the no AML group (log-rank P = .024). On Cox regression multivariate analysis, left atrial volume (hazard ratio [HR] 1.03; P = .006) and AML (HR 0.46; P = .003) were significantly associated with the primary endpoint. On univariate logistic regression, lower body mass index, older age, extensive anterior LVZ, and position of the left atrial activation breakthrough away from the AML were associated with first-pass AML block. CONCLUSION: In this retrospective matched analysis of patients with persistent AF and anterior scar, AML in addition to standard treatment was associated with improved AF/AT-free survival compared to standard treatment alone.

Left Bundle Branch Area Defibrillator (LBBAD): A First-in-Human Feasibility Study.

BACKGROUND: Left bundle branch area (LBBA) pacing is a promising pacing technique. LBBA implantable cardioverter-defibrillator (ICD) lead implantation reduces the number of leads in patients with both pacing and ICD indications, reducing cost and potentially increasing safety. LBBA positioning of ICD leads has not previously been described. OBJECTIVES: The goal of this study was to evaluate the safety and feasibility of implanting an LBBA ICD lead. METHODS: This prospective, single-center, feasibility study was conducted in patients with an ICD indication. LBBA ICD lead implantation was attempted. Acute pacing parameters and paced electrocardiography data were collected, and defibrillation testing was performed. RESULTS: LBBA defibrillator (LBBAD) implantation was attempted in 5 patients (mean age 57 ± 16.5 years; 20% female) and achieved in 3 (60%). Mean procedural and fluoroscopy duration were 170.0 ± 17.3 minutes and 28.8 ± 16.1 minutes, respectively. Left bundle capture was achieved in 2 patients (66%) and left septal capture in 1 patient. LBBA pacing exhibited a mean QRS duration and V6 R-wave peak time of 121.3 ± 8.3 milliseconds and 86.1 ± 10.0 milliseconds. In all 3 patients, defibrillation testing was successful with mean time to adequate shock delivery of 8.6 ± 2.6 seconds. Acute LBBA pacing threshold and R-wave amplitudes were 0.80 ± 0.60 V at 0.4 milliseconds and 7.0 ± 2.7 mV. No LBBA lead-related complications occurred. CONCLUSIONS: This first-in-human evaluation showed the feasibility of LBBAD implantation in a small cohort of patients. With current tools, implantation remains complex and time-consuming. Considering the feasibility reported and the potential benefits, further technological development in this field is warranted with evaluation of long-term safety and performance.