Echo state networks for the recognition of type 1 Brugada syndrome from conventional 12-LEAD ECG.

Artificial Intelligence (AI) applications and Machine Learning (ML) methods have gained much attention in recent years for their ability to automatically detect patterns in data without being explicitly taught rules. Specific features characterise the ECGs of patients with Brugada Syndrome (BrS); however, there is still ambiguity regarding the correct diagnosis of BrS and its differentiation from other pathologies. This work presents an application of Echo State Networks (ESN) in the Recurrent Neural Networks (RNN) class for diagnosing BrS from the ECG time series. 12-lead ECGs were obtained from patients with a definite clinical diagnosis of spontaneous BrS Type 1 pattern (Group A), patients who underwent provocative pharmacological testing to induce BrS type 1 pattern, which resulted in positive (Group B) or negative (Group C), and control subjects (Group D). One extracted beat in the V2 lead was used as input, and the dataset was used to train and evaluate the ESN model using a double cross-validation approach. ESN performance was compared with that of 4 cardiologists trained in electrophysiology. The model performance was assessed in the dataset, with a correct global diagnosis observed in 91.5 % of cases compared to clinicians (88.0 %). High specificity (94.5 %), sensitivity (87.0 %) and AUC (94.7 %) for BrS recognition by ESN were observed in Groups A + B vs. C + D. Our results show that this ML model can discriminate Type 1 BrS ECGs with high accuracy comparable to expert clinicians. Future availability of larger datasets may improve the model performance and increase the potential of the ESN as a clinical support system tool for daily clinical practice.

A proposed index of myocardial staining for vein of Marshall ethanol infusion: an Italian single-center experience.

BACKGROUND: Mitral isthmus (MI) conduction block is a fundamental step in anatomical approach treatment for persistent atrial fibrillation (PeAF). However, MI block is hardly achievable with endocardial ablation only. Retrograde ethanol infusion (EI) into the vein of Marshall (VOM) facilitates MI block. Fluorographic myocardial staining (MS) during VOM-EI could be helpful in predicting procedural alcoholization outcome even if its role is qualitatively assessed in the routine. The aim was to quantitatively assess MS during VOM-EI and to evaluate its association with MI block achievement. METHODS: Consecutive patients undergoing catheter ablation for PeAF at Fondazione Toscana Gabriele Monasterio (Pisa, Italy) from February 2022 to May 2023 were considered. Patients with identifiable VOM were included. A proposed index of MS (MSI) was retrospectively calculated in each included patient. Correlation of MSI with low-voltage zones (LVZ) extension after VOM-EI and its association with MI block achievement were assessed. RESULTS: In total, 42 patients out of 49 (85.8%) had an identifiable VOM. MI block was successfully achieved in 35 patients out of 42 (83.3%). MSI was significantly associated with the occurrence of MI block (OR 1.24 (1.03-1.48); p = 0.022). A higher MSI resulted in reduced ablation time (p = 0.014) and reduced radiofrequency applications (p = 0.002) to obtain MI block. MSI was also associated with MI block obtained by endocardial ablation only (OR 1.07 (1.02-1.13); p = 0.002). MSI was highly correlated with newly formed LVZ extension (r = 0.776; p = 0.001). CONCLUSIONS: In our study cohort, optimal MSI predicts MI block and facilitates its achievement with endocardial ablation only.

Impact of Vein of Marshall Ethanol Infusion Combined with Anatomical Ablation for the Treatment of Persistent Atrial Fibrillation: A Long-Term Follow-Up Based on Implantable Loop Recorders.

BACKGROUND: The best ablation treatment for persistent atrial fibrillation (PeAF) patients is still debated. The vein of Marshall (VOM) seems to be a promising target for ablation and could be combined with a linear set of ablation lesions. The aim of our study is to evaluate the incidence of AF recurrences in a PeAF population treated with a comprehensive ablation approach consisting of VOM ethanol infusion (EI), pulmonary vein isolation (PVI), a left atrial (LA) roofline, a mitral line (guided by the newly formed lesion after alcohol infusion into the VOM and validated by pacing), and a cavotricuspid isthmus line. METHODS: Consecutive patients undergoing the first ablation procedure of catheter ablation (CA) for PeAF were enrolled. All patients underwent VOM-EI, PVI, and ablation lines along the roof of the LA, mitral, and cavotricuspid isthmus. LA voltage mapping before and after VOM-EI was also performed. An implantable loop recorder (ILR) was implanted at the end of the ablation in each patient. RESULTS: Thirty-one consecutive patients (66 ± 8 years and 71% male) affected by PeAF were included in this study. The VOM-EI procedural phase lasted 21.4 ± 10.1 min. PV isolation and lines were validated in all subjects. The ML block was achieved within 10.8 ± 8.7 min. At a mean follow-up of 12 ± 7 months, 27 out of 31 (87%) patients remained free from AT/AF recurrences. Among the patients with recurrences, two (50%) had incomplete ablation lesions and three (75%) had "suboptimal" VOM-EI. In 23/31 patients (74%), antiarrhythmic drugs (AADs) were discontinued after 1 month of follow-up. No significant complications were reported during the follow-up. CONCLUSIONS: this single-center experience demonstrates that VOM-EI systematically combined with an anatomical ablation set in patients with PeAF resulted in feasible, safe, and effective freedom from AF/AT recurrences in 87% of the population after a 1-year follow-up period according to an ILR.

Mid-Term Electrical Remodeling after Percutaneous Atrial Septal Defect Closure with GCO Device in a Pediatric Population.

BACKGROUND AND AIM: The GORE® CARDIOFORM (GCO) septal occluder is an atrial septal defect/patent foramen ovale closure device with theoretical advantages over other commercialized devices thanks to its softness and anatomical compliance. Our aim was to evaluate the short- and medium-term electrocardiographic changes after percutaneous ASD closure with GCO in a pediatric population. METHODS: We enrolled 39 patients with isolated ASD submitted to trans-catheter closure from January 2020 to June 2021. ECG was performed before, at 24 h and 6 months after the procedure. P wave dispersion, QTc and QTc dispersion were calculated. ECG Holter was recorded at 6 months after implantation. RESULTS: Patients' age and body surface area (BSA) were 8.2 ± 4.2 years and 1.0 ± 0.3 m2 respectively. At the baseline, mean P wave dispersion was 40 ± 15 msec and decreased at 24 h (p < 0.002), without any further change at 6 months. At 24 h, PR conduction and QTc dispersion significantly improved (p = 0.018 and p < 0.02 respectively), while the absolute QTc value considerably improved after 6 months. During mid-term follow-up, QTc dispersion remained stable without a significant change in PR conduction. The baseline cardiac frequency was 88.6 ± 12.6 bpm, followed by a slight reduction at 24 h, with a further amelioration at 6 months after the procedure (87.3 ± 14.2, p = 0.9 and 81.0 ± 12.7, p = 0.009, respectively). After device deployment, two patients developed transient, self-limited junctional rhythm. One of them needed a short course of Flecainide for atrial ectopic tachycardia. No tachy/brady-arrhythmias were recorded at the 6-month follow-up. ASD closure resulted in a marked decrease in right heart volumes and diameters at 6 months after percutaneous closure. CONCLUSIONS: Percutaneous ASD closure with the GCO device results in significant, sudden improvement of intra-atrial, atrio-ventricular and intraventricular electrical homogeneity. This benefit persists unaltered over a medium-term follow-up. These electrical changes are associated with a documented positive right heart volumetric remodeling at mid-term follow-up.

The Subcutaneous Implantable Cardioverter-Defibrillator: A Patient Perspective.

The subcutaneous implantable cardioverter-defibrillator (S-ICD) is a new technology for the management of ICD patients. But what is the patients' perspective? Previous studies on the transvenous ICD (TV-ICD) showed that device implantation is related not only to anxiety and depression because of the fear of ICD shocks, but also to many biopsychosocial factors like body image changes, perceived reduction of socialization and limitation in professional and sports activities. Anxiety and distress are more evident in younger women because of aesthetic reasons. The scar size and the position of the S-ICD can help these patients and positively influence their social relationships. Moreover, the position of the S-ICD reduces possible complications from catheters due to stress injury and can improve patients' professional life by avoiding some work activity limitations. An S-ICD can be also a good option for athletes in avoiding subclavian crash and reducing inappropriate shocks. However, some questions remain unsolved because an S-ICD is not suitable for patients with indications for pacing, cardiac resynchronization therapy or anti-tachycardia pacing. In conclusion, the use of an S-ICD can assist physicians in reducing the negative impact of implantation on the well-being of some groups of patients by helping them to avoid depression and anxiety as well as improving their noncompliance with their medical treatment.

Cardiovascular Magnetic Resonance in Patients with Cardiac Electronic Devices: Evidence from a Multicenter Study.

BACKGROUND: Most recent cardiac implantable electronic devices (CIEDs) can safely undergo a cardiovascular magnetic resonance (CMR) scan under certain conditions, but metal artifacts may degrade image quality. The aim of this study was to assess the overall diagnostic yield of CMR and the extent of metal artifacts in a multicenter, multivendor study on CIED patients referred for CMR. METHODS: We analyzed 309 CMR scans from 292 patients (age 57 ± 16 years, 219 male) with an MR-conditional pacemaker (n = 122), defibrillator (n = 149), or loop recorder (n = 38); CMR scans were performed in 10 centers from 2012 to 2020; MR-unsafe implants were excluded. Clinical and device parameters were recorded before and after the CMR scan. A visual analysis of metal artifacts was performed for each sequence on a segmental basis, based on a 5-point artifact score. RESULTS: The vast majority of CMR scans (n = 255, 83%) were completely performed, while only 32 (10%) were interrupted soon after the first sequences and 22 (7%) were only partly acquired; CMR quality was non-diagnostic in 34 (11%) scans, poor (<1/3 sequences were diagnostic) in 25 (8%), or acceptable (1/3 to 2/3 sequences were diagnostic) in 40 (13%), while most scans (n = 201, 68%) were of overall good quality. No adverse event or device malfunctioning occurred, and only nonsignificant changes in device parameters were recorded. The most affected sequences were SSFP (median score 0.32 [interquartile range 0.07-0.91]), followed by GRE (0.18 [0.02-0.59]) and LGE (0.14 [0.02-0.55]). ICDs induced more artifacts (median score in SSFP images 0.87 [0.50-1.46]) than PMs (0.11 [0.03-0.28]) or ILRs (0.11 [0.00-0.56]). Moreover, most artifacts were located in the anterior, anteroseptal, anterolateral, and apical segments of the LV and in the outflow tract of the RV. CONCLUSIONS: CMR is a versatile imaging technique, with a high safety profile and overall good image quality even in patients with MR-conditional CIEDs. Several strategies are now available to optimize image quality, substantially enhancing overall diagnostic yield.

Matching Ablation Endpoints to Long-Term Outcome: The Prospective Multicenter Italian Ventricular Tachycardia Ablation Registry.

BACKGROUND: Multicenter ventricular tachycardia (VT) ablation studies have shown poorer outcomes compared with single-center experiences. This difference could be related to heterogeneous mapping and ablation strategies. OBJECTIVES: This study evaluated a homogenous simplified catheter ablation strategy for different substrates and compared the results with those of a single referral center. METHODS: This was a multicenter prospective VT ablation registry of patients with the following 4 causes of VT: previous myocardial infarction; previous myocarditis; arrhythmogenic right ventricular dysplasia; or idiopathic dilated cardiomyopathy. The procedural protocol included precise mapping and ablation steps with the combined endpoint of late potential (LP) abolition and noninducibility of VT. The long-term primary efficacy endpoint was freedom from VT. RESULTS: A total of 309 patients were enrolled. LPs were present in 70% of patients and were abolished in 83%. At the end of the procedure 74% of LPs were noninducible. The primary combined endpoint of LP abolition and noninducibility was achieved in 64% of patients with LPs at baseline. Freedom from VT at 12 months was observed in 67% of patients. In the overall study group, VT inducibility was the only predictor of freedom from VT (P = 0.013). In patients with LPs, the VT recurrence rate was lower both for patients with complete LP abolition (P = 0.040) and for patients meeting the composite endpoint (P = 0.035). CONCLUSIONS: A standardized VT mapping and ablation technique reproduced the procedural outcomes of a single referral center in a multicenter prospective study. LP abolition and noninducibility were effective in reducing VT recurrences in patients with 4 causes of cardiomyopathy. (Ventricular Tachycardia Ablation Registry; NCT03649022).

Prognostic value of right ventricular refractory period heterogeneity in Type-1 Brugada electrocardiographic pattern.

AIMS: To investigate the prognostic significance of heterogeneity in the refractoriness of right ventricular (RV) outflow tract (RVOT) and RV apex at the electrophysiological study (EPS) in Brugada syndrome (BrS). METHODS AND RESULTS: A cohort of BrS patients (primary prevention) from five Italian centres was retrospectively analysed. Patients with spontaneous or drug-induced Type-1 electrocardiogram (ECG) + symptoms were offered an EPS for prognostic stratification. The primary endpoint was a composite of sudden cardiac death (SCD), resuscitated cardiac arrest, or appropriate intervention by the implantable cardioverter-defibrillator (ICD). Three hundred and seventy-two patients with BrS were evaluated (44 ± 15 years, 69% males, 23% with ICD): 4 SCDs and 17 ICD interventions occurred at follow-up (median 48, interquartile range: 36-60 months). Family history of SCD, syncope, and a spontaneous Type-1 ECG pattern were univariate predictors of the primary endpoint in the whole population. In patients undergoing EPS (n = 198, 53%, 44 ± 12 years, 71% males, 39% with ICD), 3 SCD and 15 ICD interventions occurred at follow-up. In this subset, the primary endpoint was not only predicted by ventricular tachycardia/fibrillation inducibility but also by a difference in the refractory period between RVOT and RV apex (ΔRPRVOT-apex) >60 ms. ΔRPRVOT-apex > 60 ms remained an independent predictor of SCD/ICD shock at bivariate analysis, even when adjusted for the other univariate predictors, showing the highest predictive power at C-statistic analysis (0.75, 95% confidence interval 0.63-0.86). CONCLUSIONS: Heterogeneity of RV refractory periods is a strong, independent predictor of life-threatening arrhythmias in BrS patients, beyond VT/VF inducibility at EPS and common clinical predictors.

Treatment Options in AF Patients with Cancer; Focus on Catheter Ablation.

Longer life expectancy along with advancements in cancer and atrial fibrillation (AF) therapies and treatment strategies have led to an increase in the number of individuals with both diseases. As a result, the complicated management of these patients has become crucial, necessitating individualised treatment that considers the bi-directional relationship between these two diseases. On the one hand, giving appropriate pharmaceutical therapy is exceptionally difficult, considering the recognised thromboembolic risk posed by AF and malignancy, as well as the haemorrhagic risk posed by cancer. The alternative pulmonary vein isolation (PVI) ablation, on the other hand, has been inadequately explored in the cancer patient population; there is yet inadequate data to allow the clinician to unambiguously select patients that can undertake this therapeutic intervention. The goal of this review is to compile the most valuable data and supporting evidence about the characteristics, care, and therapy of cancer patients with AF. Specifically, we will evaluate the pharmaceutical options for a proper anticoagulant therapy, as well as the feasibility and safety of PVI in this population.

Association between implantable defibrillator-detected sleep apnea and atrial fibrillation: The DASAP-HF study.

INTRODUCTION: The Respiratory Disturbance Index (RDI) computed by an implantable cardioverter defibrillator (ICD) algorithm accurately identifies severe sleep apnea (SA). In the present analysis, we tested the hypothesis that RDI could also predict atrial fibrillation (AF) burden. METHODS: Patients with ejection fraction ≤35% implanted with an ICD were enrolled and followed up for 24 months. One month after implantation, patients underwent a polysomnographic study. The weekly mean RDI value was considered, as calculated during the entire follow-up period and over a 1-week period preceding the sleep study. The endpoints were as follows: daily AF burden of ≥5 min, ≥6 h, ≥23 h. RESULTS: Here, 164 patients had usable RDI values during the entire follow-up period. Severe SA (RDI ≥ 30 episodes/h) was diagnosed in 92 (56%) patients at the time of the sleep study. During follow-up, AF burden ≥ 5 min/day was documented in 70 (43%), ≥6 h/day in 48 (29%), and ≥23 h/day in 33 (20%) patients. Device-detected RDI ≥ 30 episodes/h at the time of the polygraphy, as well as the polygraphy-measured apnea hypopnea index ≥ 30 episodes/h, were not associated with the occurrence of the endpoints, using a Cox regression model. However, using a time-dependent model, continuously measured weekly mean RDI ≥ 30 episodes/h was independently associated with AF burden ≥ 5 min/day (hazard ratio [HR]: 2.13, 95% confidence interval [CI]: 1.24-3.65, p = .006), ≥6 h/day (HR: 2.75, 95% CI: 1.37-5.49, p = .004), and ≥23 h/day (HR: 2.26, 95% CI: 1.05-4.86, p = .037). CONCLUSIONS: In heart failure patients, ICD-diagnosed severe SA on follow-up data review identifies patients who are from two- to three-fold more likely to experience an AF episode, according to various thresholds of daily AF burden.

Performance of transcatheter pacing system use in relation to patients' age.

PURPOSE: Real-world safety data on the use of transcatheter pacing systems particularly in very elderly patients is still limited. The aim of this analysis was to investigate the effect of age on the safety and efficacy of leadless pacemaker implant. METHODS: From May 2016 through July 2019, 577 patients were implanted with a leadless single-chamber pacemaker according to current pacing indication in 15 Italian cardiologic centers. The population was divided into age quartiles for evaluation, including (1) < 70 years, (2) 70-77 years, (3) 78-83 years, and (4) ≥ 83 years. Procedural data, complications, and electrical parameters were collected at baseline and during the follow-up. RESULTS: Procedural-related complication occurrence was very low (< 1.0%) and similar in the four subgroups according to age even if the older patients were more frail. No cardiac tamponade was reported. Among the groups, no difference was observed in procedural time, fluoroscopy time duration, and electrical parameters (mean pacing impedance: 750 ± 192 and 599 ± 156, mean pacing threshold: 0.7 ± 0.5 and 0.7 ± 0.6, and mean right ventricular sensing 10.7 ± 6.1 and 11.5 ± 4.8 at implant and last follow-up, respectively). CONCLUSIONS: The reported data demonstrated a high degree of safety during leadless implant across all patient ages. Procedural complications and device electrical measurements were similar among the different ages.

Does Timing of Ventricular Tachycardia Ablation Affect Prognosis in Patients With an Implantable Cardioverter Defibrillator? Results From the Multicenter Randomized PARTITA Trial.

BACKGROUND: Optimal timing for catheter ablation of ventricular tachycardia is an important unresolved issue. There are no randomized trials evaluating the benefit of ablation after the first implantable cardioverter defibrillator (ICD) shock. METHODS: We conducted a 2-phase, prospective, multicenter, randomized clinical trial. Patients with ischemic or nonischemic dilated cardiomyopathy and primary or secondary prevention indication for ICD were enrolled in an initial observational phase until first appropriate shock (phase A). After reconsenting, patients were randomly assigned 1:1 in phase B to immediate ablation (within 2 months from shock delivery) or continuation of standard therapy. The primary end point was a composite of death from any cause or hospitalization for worsening heart failure. Amiodarone intake was not allowed except for documented atrial tachyarrhythmias. On July 23, 2021, phase B of the trial was interrupted as a result of the first interim analysis on the basis of the Bayesian adaptive design. RESULTS: Of the 517 patients enrolled in phase A, 154 (30%) had ventricular tachycardia, 56 (11%) received an appropriate shock over a median follow-up of 2.4 years (interquartile range, 1.4-4.4), and 47 of 56 (84%) agreed to participate in phase B. After 24.2 (8.5-24.4) months, the primary end point occurred in 1 of 23 (4%) patients in the ablation group and 10 of 24 (42%) patients in the control group (hazard ratio, 0.11 [95% CI, 0.01-0.85]; P=0.034). The results met the prespecified termination criterion of >99% Bayesian posterior probability of superiority of treatment over standard therapy. No deaths were observed in the ablation group versus 8 deaths (33%) in the control group (P=0.004); there was 1 worsening heart failure hospitalization in the ablation group (4%) versus 4 in the control group (17%; P=0.159). ICD shocks were less frequent in the ablation group (9%) than in the control group (42%; P=0.039). CONCLUSIONS: Ventricular tachycardia ablation after first appropriate shock was associated with a reduced risk of the combined death or worsening heart failure hospitalization end point, lower mortality, and fewer ICD shocks. These findings provide support for considering ventricular tachycardia ablation after the first ICD shock. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT01547208.

Incidence and Predictors of Infections and All-Cause Death in Patients with Cardiac Implantable Electronic Devices: The Italian Nationwide RI-AIAC Registry.

BACKGROUND: The incidence of infections associated with cardiac implantable electronic devices (CIEDs) and patient outcomes are not fully known. AIM: To provide a contemporary assessment of the risk of CIEDs infection and associated clinical outcomes. METHODS: In Italy, 18 centres enrolled all consecutive patients undergoing a CIED procedure and entered a 12-months follow-up. CIED infections, as well as a composite clinical event of infection or all-cause death were recorded. RESULTS: A total of 2675 patients (64.3% male, age 78 (70-84)) were enrolled. During follow up 28 (1.1%) CIED infections and 132 (5%) deaths, with 152 (5.7%) composite clinical events were observed. At a multivariate analysis, the type of procedure (revision/upgrading/reimplantation) (OR: 4.08, 95% CI: 1.38-12.08) and diabetes (OR: 2.22, 95% CI: 1.02-4.84) were found as main clinical factors associated to CIED infection. Both the PADIT score and the RI-AIAC Infection score were significantly associated with CIED infections, with the RI-AIAC infection score showing the strongest association (OR: 2.38, 95% CI: 1.60-3.55 for each point), with a c-index = 0.64 (0.52-0.75), p = 0.015. Regarding the occurrence of composite clinical events, the Kolek score, the Shariff score and the RI-AIAC Event score all predicted the outcome, with an AUC for the RI-AIAC Event score equal to 0.67 (0.63-0.71) p < 0.001. CONCLUSIONS: In this Italian nationwide cohort of patients, while the incidence of CIED infections was substantially low, the rate of the composite clinical outcome of infection or all-cause death was quite high and associated with several clinical factors depicting a more impaired clinical status.

Cardiac resynchronization therapy defibrillators in patients with permanent atrial fibrillation.

AIMS: There are conflicting data on the benefit of cardiac resynchronization therapy (CRT) in heart failure (HF) patients with permanent atrial fibrillation (AF). We aimed to compare patient outcomes according to the presence or absence of permanent AF at device implantation. METHODS AND RESULTS: We retrospectively analysed remote monitoring data from 1141 CRT defibrillators. Propensity score with inverse-probability weighting method was used to balance AF and sinus rhythm (SR) groups. Analysis endpoints included total mortality, appropriate defibrillation shocks, and CRT percentage. There were 229 patients (20.1%) in the AF group and 912 patients (79.9%) in the SR group. Compared with SR patients, AF patients were older (median age, 77 vs. 72 years, P < 0.001), more frequently male (82.5% vs. 75.5%, P = 0.02), and had higher heart rate (75.7 vs. 71.0 b.p.m., P < 0.001). Of the 229 AF patients, 162 (70.7%) received suboptimal CRT (<98%) and 67 (29.3%) had adequate CRT (≥98%). During a median follow-up of 24 months, total mortality did not differ between AF and SR groups (propensity-score-weighted hazard ratio, HR 1.32 [95% confidence interval, 0.82-2.15], P = 0.25). The risk of appropriate shocks was significantly higher in the AF group with <98% CRT than in the SR group (weighted-HR, 1.99 [1.21-3.26], P = 0.006) and was similar in the AF group with ≥98% CRT versus the SR group (1.29 [0.66-2.53], P = 0.45). During follow-up, sinus rhythm was recovered in 23 patients in the AF group (10%) after a median time of 106 (42-256) days. The rate of sinus rhythm recovery in the AF group was 4.5 (95% CI, 2.8-6.7) per 100 patient-years; the rate of permanent AF occurrence in the SR group was 2.5 (95% CI, 1.9-3.3) per 100 patient-years. CONCLUSIONS: Although mortality was similar across patient groups, patients with permanent AF and suboptimal CRT had twofold higher risk of appropriate shocks than SR patients or AF patients with CRT ≥ 98%.

Prolonged care delivery time and reduced rate of electrophysiological procedures during the lockdown period due to Covid-19 outbreak.

OBJECTIVES: The aim of this study is to demonstrate how Electrophysiology activity has been impacted by the pandemic Coronavirus disease 2019 (COVID-19). METHODS: In this multicenter retrospective study, we analyze all consecutive patients admitted for electrophysiological procedures during the COVID-19 lockdown in the Tuscany region of Italy, comparing them to patients hospitalized in the corresponding period of the previous year. RESULTS: The impact of COVID-19 on cardiac arrhythmia management was impressive, with a reduction of more than 50% in all kinds of procedures. A gender gap was observed, with a more relevant reduction for female patients. Arrhythmic urgencies requiring a device implant showed a reduced time from symptoms to first medical contact but the time from first medical contact to procedure was significantly prolonged. CONCLUSION: Hospitals need to consider how outbreaks may affect health systems beyond the immediate infection. Routine activity should be based on a risk assessment between the prompt performance of procedure and its postponement. Retrospective observational analysis such as this study could be decisive in evidence-based medicine of any future pathogen outbreak.Nonstandard Abbreviations and Acronyms PM= pacemakerICD= implantable cardioverter defibrillatorECV= electrical cardioversionEPS= electrophysiological studyAP= ablations proceduresCIED= cardiac implantable electronic devicesWCD= wearable cardioverter defibrillatorEP Lab= Electrophysiology LaboratoriesAVNRT =atrioventricular nodal reentry tachycardiaAVRT= atrioventricular reentry tachycardiaAFL= atrial flutterAF= atrial fibrillationVT= ventricular tachycardiaAT= atrial tachycardia.

Prognostic value of implantable defibrillator-computed respiratory disturbance index: The DASAP-HF study.

BACKGROUND: Sleep apnea, as measured by polysomnography, is associated with adverse outcomes in heart failure. The DASAP-HF (Diagnosis and Treatment of Sleep Apnea in Patient With Heart Failure) study previously demonstrated that the respiratory disturbance index (RDI) computed by the ApneaScan algorithm (Boston Scientific) accurately identifies severe sleep apnea in implantable cardioverter-defibrillator (ICD) patients. OBJECTIVE: The purpose of the long-term study phase was to assess the incidence of clinical events after 24 months and investigate the association with RDI values. METHODS: Patients with left ventricular ejection fraction ≤35% implanted with an ICD were enrolled and followed-up for 24 months. The RDI calculated at 1 month after implantation was used to stratify patients (below or above 30 episodes/h). The endpoints were all-cause death and a combination of all-cause death or cardiovascular hospitalization. RESULTS: Of the 265 enrolled patients, 224 had usable RDI values. Severe sleep apnea (RDI ≥30 episodes/h) was diagnosed in 115 patients (51%). These patients were more frequently male (84% vs 72%; P = .030) and had higher creatinine levels. During median follow-up of 25 months, 19 patients (8%) died. Cardiovascular hospitalizations were reported in 19 patients (8%). The risk of all-cause death was higher in patients with RDI ≥30 episodes/h (hazard ratio [HR] 3.33; 95% confidence interval [CI] 1.35-8.21; P = .023), as well as the risk of all-cause death or cardiovascular hospitalization (HR 1.94; 95% CI 1.01-3.76; P = .048). At multivariate analysis, independent predictors of death were RDI ≥30 episodes/h (HR 4.02; 95% CI 1.16-13.97; P = .029) and creatinine levels (HR 2.36; 95% CI 1.26-4.42; P = .008). CONCLUSION: In heart failure patients implanted with an ICD, higher RDI values are associated with death and cardiovascular hospitalizations. Device-detected severe sleep apnea independently predicts death.

Catheter cryoablation of ventricular ectopy originating from his region.

Careful mapping, early detection of AV conduction damage and cryothermal energy availability are essential in dealing with ablation procedures at the parahisian region.

The extent and location of late gadolinium enhancement predict defibrillator shock and cardiac mortality in patients with non-ischaemic dilated cardiomyopathy.

BACKGROUND: In non-ischaemic dilated cardiomyopathy (NIDCM), it is uncertain which late gadolinium enhancement (LGE) pattern, extent and location predict ventricular arrhythmias. METHODS: We analysed 183 NIDCM patients (73% men, median age 66 years) receiving an implantable cardioverter defibrillator (ICD) for primary prevention, undergoing cardiac magnetic resonance within 1 month before implantation. The primary endpoint was appropriate ICD shock, the secondary endpoint was a composite of appropriate ICD shock and cardiac death. RESULTS: LGE was found in 116 patients (63%), accounting for 9% of LV mass (5-13%). Over a 30-month follow-up (10-65), 20 patients (11%) experienced the primary and 30 patients (16%) the secondary endpoint. LGE presence, inferior wall LGE, diffuse (≥2 wall) LGE, the number of segments with LGE, the number of segments with 50-75% transmural LGE, and percent LGE mass were univariate predictors of both endpoints. Also septal LGE predicted the primary, and lateral LGE predicted the secondary endpoint. LGE limited to right ventricular insertion points did not predict any endpoint. Percent LGE mass had an area under the curve of 0.734 for the primary endpoint, with 13% as the best cut-off (55% sensitivity, 86% specificity, 32% PPV, 94% NPV), conferring a 7-fold higher risk compared to patients with no LGE or LGE <13%. Survival free from both endpoints was significantly worse for patients with LGE ≥13%. CONCLUSIONS: In patients with NIDCM receiving a defibrillator for primary prevention, LGE presence and extent predicted appropriate ICD shock and cardiac mortality; also specific LGE patterns and locations predicted a worse prognosis.

MicroRNA therapy stimulates uncontrolled cardiac repair after myocardial infarction in pigs.

Prompt coronary catheterization and revascularization have markedly improved the outcomes of myocardial infarction, but have also resulted in a growing number of surviving patients with permanent structural damage of the heart, which frequently leads to heart failure. There is an unmet clinical need for treatments for this condition1, particularly given the inability of cardiomyocytes to replicate and thereby regenerate the lost contractile tissue2. Here we show that expression of human microRNA-199a in infarcted pig hearts can stimulate cardiac repair. One month after myocardial infarction and delivery of this microRNA through an adeno-associated viral vector, treated animals showed marked improvements in both global and regional contractility, increased muscle mass and reduced scar size. These functional and morphological findings correlated with cardiomyocyte de-differentiation and proliferation. However, subsequent persistent and uncontrolled expression of the microRNA resulted in sudden arrhythmic death of most of the treated pigs. Such events were concurrent with myocardial infiltration of proliferating cells displaying a poorly differentiated myoblastic phenotype. These results show that achieving cardiac repair through the stimulation of endogenous cardiomyocyte proliferation is attainable in large mammals, however dosage of this therapy needs to be tightly controlled.