Conduction System Stimulation to Avoid Left Ventricle Dysfunction.

BACKGROUND: Right ventricular apical pacing (RVAP) can produce left ventricle dysfunction. Conduction system pacing (CSP) has been used successfully to reverse left ventricle dysfunction in patients with left bundle branch block. To date, data about CSP prevention of left ventricle dysfunction in patients with preserved left ventricular ejection fraction (LVEF) are scarce and limited mostly to nonrandomized studies. Our aim is to demonstrate that CSP can preserve normal ventricular function compared with RVAP in the setting of a high burden of ventricular pacing. METHODS: Consecutive patients with a high-degree atrioventricular block and preserved or mildly deteriorated LVEF (>40%) were included in this prospective, randomized, parallel, controlled study, comparing conventional RVAP versus CSP. RESULTS: Seventy-five patients were randomized, with no differences between basal characteristics in both groups. The stimulated QRS duration was significantly longer in the RVAP group compared with the CSP group (160.4±18.1 versus 124.2±20.2 ms; p<0.01). Seventy patients were included in the intention-to-treat analyses. LVEF showed a significant decrease in the RVAP group at 6 months compared with the CSP group (mean difference, -5.8% [95% CI, -9.6% to -2%]; P<0.01). Left ventricular end-diastolic diameter showed an increase in the RVAP group compared with the CSP group (mean difference, 3.2 [95% CI, 0.1-6.2] mm; P=0.04). Heart failure-related admissions were higher in the RVAP group (22.6% versus 5.1%; P=0.03). CONCLUSIONS: Conduction system stimulation prevents LVEF deterioration and heart failure-related admissions in patients with normal or mildly deteriorated LVEF requiring a high burden of ventricular pacing. These results are only short term and need to be confirmed by further larger studies. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT06026683.

Cardiac Tomography and Cardiac Magnetic Resonance to Predict the Absence of Intracardiac Thrombus in Anticoagulated Patients Undergoing Atrial Fibrillation Ablation.

Background: Pulmonary veins isolation (PVI) is a standard treatment for recurrent atrial fibrillation (AF). Uninterrupted anticoagulation for a minimum of 3 weeks before ablation and exclusion of left atrial (LA) thrombus with transesophageal echography (TEE) immediately before or during the procedure minimize peri-procedural risk. We aimed to demonstrate the utility of cardiac tomography (CT) and cardiac magnetic resonance (CMR) to rule out LA thrombus prior to PVI. Methods: Patients undergoing PVI for recurrent AF were retrospectively evaluated. Only patients that started anticoagulation at least 3 weeks prior to the CT/CMR and subsequently uninterrupted until the ablation procedure were selected. An intracardiac echo (ICE) catheter was used in all patients to evaluate LA thrombus. The results of CT/CMR were compared to ICE imaging. Results: We included 272 consecutive patients averaging 54.5 years (71% male; 30% persistent AF). Average CHA2DS2VASC score was 0.9 ± 0.83 and mean LA diameter was 42 ± 5.7 mm, 111 (41%) patients were on Acenocumarol and 161 (59%) were on direct oral anticoagulants. Anticoagulation was started 227 ± 392 days before the CT/CMR, and 291 ± 416 days before the ablation procedure. CT/CMR diagnosed intracardiac thrombus in two cases, both in the LA appendage. A new CT/CMR revealed resolution of thrombus after six additional months of uninterrupted anticoagulation. No macroscopic thrombus was observed in any patients with ICE (negative predictive value of 100%; p < 0.01). Conclusions: CT and MRI are excellent surrogates to TEE and ICE to rule out intracardiac thrombus in patients adequately anticoagulated prior AF ablation. This is true even for delayed procedures as long as anticoagulation is uninterrupted.

Cryoballoon Ablation for Persistent and Paroxysmal Atrial Fibrillation: Procedural Differences and Results from the Spanish Registry (RECABA).

Introduction: Cryoballoon ablation (CBA) has become a standard treatment for paroxysmal atrial fibrillation (PaAF) but limited data is available for outcomes in patients with persistent atrial fibrillation (PeAF). Methods: We analyzed the first 944 patients included in the Spanish Prospective Multi-center Observation Post-market Registry to compare characteristics and outcomes of patients undergoing CBA for PeAF versus PaAF. Results: A total of 944 patients (57.8 ± 10.4 years; 70.1% male) with AF (27.9% persistent) were prospectively included from 25 centers. PeAF patients were more likely to have structural heart disease (67.7 vs. 11.4%; p < 0.001) and left atrium dilation (72.6 vs. 43.3%; p < 0.001). CBA of PeAF was less likely to be performed under general anesthesia (10.7 vs. 22.2%; p < 0.001), with an arterial line (32.2 vs. 44.6%; p < 0.001) and assisted transeptal puncture (11.9 vs. 17.9%; p = 0.025). During an application, PeAF patients had a longer time to −30 °C (35.91 ± 14.20 vs. 34.93 ± 12.87 s; p = 0.021) and a colder balloon nadir temperature during vein isolation (−35.04 ± 9.58 vs. −33.61 ± 10.32 °C; p = 0.004), but received fewer bonus freeze applications (30.7 vs. 41.1%; p < 0.001). There were no differences in acute pulmonary vein isolation and procedure-related complications. Overall, 76.7% of patients were free from AF recurrences at 15-month follow-up (78.9% in PaAF vs. 70.9% in PeAF; p = 0.09). Conclusions: Patients with PeAF have a more diseased substrate, and CBA procedures performed in such patients were more simplified, although longer/colder freeze applications were often applied. The acute efficacy/safety profile of CBA was similar between PaAF and PeAF patients, but long-term results were better in PaAF patients.

Plasma levels of miRNA-1-3p are associated with subclinical atrial fibrillation in patients with cryptogenic stroke.

INTRODUCTION AND OBJECTIVES: Identifying biomarkers of subclinical atrial fibrillation (AF) is of most interest in patients with cryptogenic stroke (CrS). We sought to evaluate the circulating microRNA (miRNA) profile of patients with CrS and AF compared with those in persistent sinus rhythm. METHODS: Among 64 consecutive patients with CrS under continuous monitoring by a predischarge insertable monitor, 18 patients (9 with AF and 9 in persistent sinus rhythm) were selected for high-throughput determination of 754 miRNAs. Nine patients with concomitant stroke and AF were also screened to improve the yield of miRNA selection. Differentially expressed miRNAs were replicated in an independent cohort (n=46). Biological markers were stratified by the median and included in logistic regression analyses to evaluate their association with AF at 6 and 12 months. RESULTS: Eight miRNAs were differentially expressed between patients with and without AF. In the replication cohort, miR-1-3p, a gene regulator involved in cardiac arrhythmogenesis, was the only miRNA to remain significantly higher in patients with CrS and AF vs those in sinus rhythm and showed a modest association with AF burden. High (= above the median) miR-1-3p plasma values, together with a low left atrial ejection fraction, were independently associated with the presence of AF at 6 and 12 months. CONCLUSIONS: In this cohort, plasma levels of miR-1-3p were elevated in CrS patients with subsequent AF. Our results preliminarily suggest that miR-1-3p could be a novel biomarker that, together with clinical parameters, could help identify patients with CrS and a high risk of occult AF.

Influence of PACE score and conduction disturbances in the incidence of early new onset atrial fibrillation after typical atrial flutter ablation.

PURPOSE: Patients undergoing cavotricuspid isthmus (CTI) ablation for typical flutter (AFL) have a high incidence of new onset atrial fibrillation (AF). We aimed to analyze the influence of PACE score to predict new onset AF in this subset of patients to stratify thromboembolic risk. METHODS: Between 2017 and 2019, patients undergoing CTI ablation for AFL and without history of AF were prospectively included. All patients were monitored continuously by implantable loop recorder and followed by remote monitoring. RESULTS: Overall 48 patients were included. New onset AF rate at 12 months was 56.3%. We observed two very strong independent predictors for new onset AF: a PACE score ≥ 30 (HR:6.9; 95% CI:1.71-27.91; p = 0.007) and an HV interval ≥ 55 (HR:11.86; 95% CI:2.57-54.8; p = 0.002). CONCLUSIONS: The incidence of newly diagnosed AF is high in patients with AFL after CTI ablation, and can occur early. A high PACE score and/or long HV interval predict even higher risk, and may be useful in the decision for empiric long-term anticoagulation.

Merged two-way mapping technique: an alternative 3D electroanatomical mapping approach to guide challenging ablation procedures of accessory pathways with bidirectional conduction properties.

BACKGROUND: Catheter ablation of accessory pathways (AP) with bidirectional conduction may be challenging due to issues related to anatomical course or location. OBJECTIVE: We describe an alternative electro-anatomical mapping technique which aims at depicting the entire anatomic course of the AP from the atrial toward the ventricular insertion in order to guide catheter ablation. METHODS: Twenty consecutive patients with confirmed bidirectional AP conduction and at least one previous ablation procedure or para-Hisian location were included. 3-D electro-anatomical mapping was used to depict the merged 10-ms isochrone area of maximum early activation of both the ventricular and atrial signals during sinus rhythm and ventricular pacing/orthodromic tachycardia, respectively. Catheter ablation was performed within the depicted earliest isochrone area. RESULTS: Acute bidirectional AP conduction block was achieved in all patients 4.2 ± 1.7 s after the first radiofrequency energy pulse was delivered, without reconnection during a 30 ± 10 min post-ablation observation time. No procedural complications were seen. After a mean follow-up period of 9 ± 7 months (range 3 to 16), no recurrences were documented. CONCLUSION: This merged two-way mapping technique is a safe, efficient, and effective technique for ablation of APs with bidirectional conduction.

Primary results of the Spanish Cryoballoon Ablation Registry: acute and long-term outcomes of the RECABA study.

Cryoablation is safe and effective for the treatment of atrial fibrillation (AF) in controlled clinical trials, but contemporary real-world usage and outcomes are limited. The Report of the Spanish Cryoballoon Ablation Registry (RECABA) was designed to evaluate acute and 12-month outcomes of cryoballoon ablation for the treatment of AF in Spain. Patients from 27 Spanish centers were prospectively enrolled. Patients were treated with cryoballoon ablation and managed according to standard of care protocols at each center. The primary endpoint was ≥ 30 s freedom from AF at 12-month after a 3-month blanking period. Secondary endpoints included a description of patient characteristics, cryoablation procedural strategy and safety, and predictors of efficacy. In total, 1742 patients (71.4% PAF, 68.8% male, mean age 58.02 ± 10.40 years, 76.1% overweight or obese, CHA2DS2-VASc index 1.40 ± 1.28) were enrolled. Patients received 7.2 ± 2.67 cryo-applications. PV potentials could be detected in 61% of the PVs during ablation, with a mean time to block of 52.9 ± 37.02 s. Acute PVI was observed in 97% of PVs with 75.8% isolated with the first cryo-application. Mean procedural time was 113 ± 41 min. Acute complications occurred in 4.4% of the cases. With follow-up in 1628 patients, AF-free survival was 78.5% (PAF: 80.6% vs PersAF 73.3%; p < 0.001). Left atrium enlargement, female sex, non-PAF, and early recurrence were independent predictors of AF recurrence (p < 0.05). RECABA provides detailed insight into current dosing practices and demonstrates cryoablation is safe and effective in real-world use.ClinicalTrials.gov number: NCT02785991.

Reduction in new cardiac electronic device implantations in Catalonia during COVID-19.

AIMS: During the COVID-19 pandemic, concern regarding its effect on the management of non-communicable diseases has been raised. However, there are no data on the impact on cardiac implantable electronic devices (CIED) implantation rates. We aimed to determine the impact of SARS-CoV2 on the monthly incidence rates and type of pacemaker (PM) and implantable cardiac defibrillator (ICD) implantations in Catalonia before and after the declaration of the state of alarm in Spain on 14 March 2020. METHODS AND RESULTS: Data on new CIED implantations for 2017-20 were prospectively collected by nine hospitals in Catalonia. A mixed model with random intercepts corrected for time was used to estimate the change in monthly CIED implantations. Compared to the pre-COVID-19 period, an absolute decrease of 56.5% was observed (54.7% in PM and 63.7% in ICD) in CIED implantation rates. Total CIED implantations for 2017-19 and January and February 2020 was 250/month (>195 PM and >55 ICD), decreasing to 207 (161 PM and 46 ICD) in March and 131 (108 PM and 23 ICD) in April 2020. In April 2020, there was a significant fall of 185.25 CIED implantations compared to 2018 [95% confidence interval (CI) 129.6-240.9; P < 0.001] and of 188 CIED compared to 2019 (95% CI 132.3-243.7; P < 0.001). No significant differences in the type of PM or ICD were observed, nor in the indication for primary or secondary prevention. CONCLUSIONS: During the first wave of the COVID-19 pandemic, a substantial decrease in CIED implantations was observed in Catalonia. Our findings call for measures to avoid long-term social impact.

Obstructive Sleep Apnea Syndrome as a Trigger of Cardiac Arrhythmias.

PURPOSE OF REVIEW: Obstructive sleep apnea syndrome (OSAS) has a high prevalence in western countries. Many papers have been published with the purpose of demonstrating that OSAS acts as an arrhythmia trigger and is responsible for an increase in cardiovascular morbidity and mortality. The aim of this study was to review our knowledge on this topic. RECENT FINDINGS: There is a lot of evidence demonstrating the relationship between OSAS and arrhythmias, but there remains a lack of an interventional randomized trial to demonstrate that by treating OSAS we can reduce arrhythmia burden. OSAS is a highly prevalent illness in western countries and is clearly related to an increase in cardiovascular mortality and morbidity. Cardiac arrhythmias are triggered by a repetitive hypoxemia, hypercapnia, acidosis, intrathoracic pressure fluctuations, reoxygenation, and arousals during apnea and hypopnea episodes. Early diagnosis and treatment of these patients can reduce further cardiovascular morbidity and mortality.

Prolonged QT Interval in SARS-CoV-2 Infection: Prevalence and Prognosis.

BACKGROUND: The prognostic value of a prolonged QT interval in SARS-Cov2 infection is not well known. OBJECTIVE: To determine whether the presence of a prolonged QT on admission is an independent factor for mortality in SARS-Cov2 hospitalized patients. METHODS: Single-center cohort of 623 consecutive patients with positive polymerase-chain-reaction test (PCR) to SARS Cov2, recruited from 27 February to 7 April 2020. An electrocardiogram was taken on these patients within the first 48 h after diagnosis and before the administration of any medication with a known effect on QT interval. A prolonged QT interval was defined as a corrected QT (QTc) interval >480 milliseconds. Patients were followed up with until 10 May 2020. RESULTS: Sixty-one patients (9.8%) had prolonged QTc and only 3.2% had a baseline QTc > 500 milliseconds. Patients with prolonged QTc were older, had more comorbidities, and higher levels of immune-inflammatory markers. There were no episodes of ventricular tachycardia or ventricular fibrillation during hospitalization. All-cause death was higher in patients with prolonged QTc (41.0% vs. 8.7%, p < 0.001, multivariable HR 2.68 (1.58-4.55), p < 0.001). CONCLUSIONS: Almost 10% of patients with COVID-19 infection have a prolonged QTc interval on admission. A prolonged QTc was independently associated with a higher mortality even after adjustment for age, comorbidities, and treatment with hydroxychloroquine and azithromycin. An electrocardiogram should be included on admission to identify high-risk SARS-CoV-2 patients.

Mapping potentials adjacent to the cavo-tricuspid isthmus ablation line during incremental pacing: A feasible and highly accurate maneuver to confirm complete CTI conduction block.

BACKGROUND: The diagnostic accuracy of incremental atrial pacing (IP) to determine complete cavo-tricuspid isthmus (CTI) block during typical atrial flutter (AFL) ablation is limited by both an extensive/nonlinear ablation and/or the presence of intra-atrial conduction delay elsewhere in the right atrium. We examined the diagnostic performance of an IP variant based on the assessment of the atrial potentials adjacent to the ablation line which aims at overcoming both limitations. METHODS: From a prospective population of 108 consecutive patients, 15 were excluded due to observation of inconclusive CTI ablation potentials precluding for a straight comparison between the IP maneuver and its variant. In the remaining 93, IP was performed from the low lateral right atrium and the coronary sinus ostium, with the ablation catheter positioned both at the CTI line and adjacent (<5 mm) to its septal and lateral aspect. The IP variant consisted of measuring the interval between the two atrial electrograms situated on the same side of the ablation line, opposite to the pacing site, a ≤10 ms increase indicating complete CTI block. RESULTS: The IP maneuver and its variant were consistent with complete CTI block in 82/93 (88%) and 87/93 (93%) patients, respectively. Four patients had AFL recurrence during follow-up: 2/4 and 4/4 had been adequately classified as incomplete block by the IP maneuver and its variant, respectively. Twenty-three patients (24%) had significant intra-atrial conduction delay elsewhere in the right atrium. The IP maneuver and its variant were suggestive of an incomplete CTI block in 11/23 and 4/23 in this setting (P = .028), with the later best predicting subsequent AFL relapses (2/12 vs 2/4, P = .01). CONCLUSIONS: The IP variant, which was designed to overcome the limitations of the conventional IP maneuver, accurately distinguishes complete from incomplete CTI block and helps to predict AFL recurrences after ablation.

Ablación no invasiva de taquicardia ventricular con radioterapia estereotáctica en un paciente con miocardiopatía arritmogénica de ventrículo derecho / Noninvasive ablation of ventricular tachycardia with stereotactic radiotherapy in a patient with arrhythmogenic right ventricular cardiomyopathy

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Diagnosis-to-ablation time in atrial fibrillation: A modifiable factor relevant to clinical outcome.

INTRODUCTION: Recurrences after atrial fibrillation (AF) ablation are still common. Among the reported clinical and imaging predictors of recurrences, diagnosis-to-ablation time (DAT) has been defined as a predictor of ablation outcome in single-center studies. We aimed to validate DAT in a multicenter real-life cohort. METHODS: This was a multicenter study including consecutive patients undergoing first paroxysmal and persistent AF ablation with radiofrequency or cryoballoon catheters during 2013. Cox proportional hazard regression models were performed to identify predictors of recurrence. RESULTS: In total, 309 patients were included across nine centers (71% men, 57 ± 10 years old, 46% with hypertension, and 66% with CHA2 DS2 -VASc ≤ 1). Most patients had paroxysmal AF (67%) and underwent radiofrequency ablation (68%) with a median DAT of 51 (43) months. Patients with DAT ≤ 1 year (16.6%) were less likely to have repeat procedures (4% vs 18%; P = .017). The adjusted proportional hazards Cox model identified hypertension (P = .005), heart failure (P = .011), nonparoxysmal AF (P = .038), DAT > 1 year (P = .007), and LA diameter (P = .026) as independent predictors for AF recurrence. DAT > 1 year was the only modifiable factor independently associated with recurrence (HR 4.2 [95% CI, 1.5-11.9]) CONCLUSION: Diagnosis-to-ablation time is a modifiable factor independently associated with recurrent arrhythmia and repeat ablation after first AF ablation. An early intervention strategy during the first year from AF diagnosis might improve outcomes.

Double factor single shot to diminish complications in cryoballoon ablation procedures for atrial fibrillation.

PURPOSE: Cryoballoon ablation (CBA) has become a standard treatment for recurrent atrial fibrillation (AF). There is need for improved CBA protocols. We aimed to demonstrate that a new protocol including minimum temperature (minT) reached could reduce procedure times and complications. METHODS: A new double factor protocol (DFP), based on the performance of one single shot per vein with variable duration, and conditional bonus shot, determined by time-to-effect (TTE) and minT, was compared with the conventional protocol (CP), with at least two shots per vein. Procedure parameters, complications, and efficacy were compared. RESULTS: We prospectively included 88 consecutive patients treated with the DFP. These were compared to the previous consecutive 69 patients treated with CP. All procedures were performed with 28-mm second-generation balloon. Acute pulmonary vein (PV) isolation was similar (98.6% vs. 98.9% in CP vs. DFP, p = 0.687). Procedure and ablation times favored DFP over CP (120 vs. 134 min, p = 0.003; and 1051 vs. 1475 s, p < 0.001; respectively). A composite of major and minor complications was significantly reduced in the DFP compared to the CP (18.8% vs. 6.8%, p = 0.02; respectively). Within a follow-up of 18 months, freedom from AF was 79.7% in CP and 78.4% in DFP (Log-rank 0.501). Paroxysmal AF and absence of PV potentials predicted better arrhythmia outcomes (HR 2.14 for paroxysmal vs. persistent, p = 0.031; and HR 1.61 for absence vs. presence of PV potentials, p = 0.01). CONCLUSIONS: The novel DFP results in reduced complication rates and procedure times, with similar success rates compared with a conventional strategy.

Left atrial geometry and outcome of atrial fibrillation ablation: results from the multicentre LAGO-AF study.

Aims: Left atrial (LA) remodelling is a key determinant of atrial fibrillation (AF) ablation outcome. Optimal methods to assess this process are scarce. LA sphericity is a shape-based parameter shown to be independently associated to procedural success. In a multicentre study, we aimed to test the feasibility of assessing LA sphericity and evaluate its capability to predict procedural outcomes. Methods and results: This study included consecutive patients undergoing first AF ablation during 2013. A 3D model of the LA chamber, excluding pulmonary veins and LA appendage, was used to quantify LA volume (LAV) and LA sphericity (≥82.1% was considered spherical LA). In total, 243 patients were included across 9 centres (71% men, aged 56 ± 10 years, 44% with hypertension and 76% CHA2DS2-VASc ≤ 1). Most patients had paroxysmal AF (66%) and underwent radiofrequency ablation (60%). Mean LA diameter (LAD), LAV, and LA sphericity were 42 ± 6 mm, 100 ± 33 mL, and 82.6 ± 3.5%, respectively. Adjusted Cox models identified paroxysmal AF [hazard ratio (HR 0.54, P = 0.032)] and LA sphericity (HR 1.87, P = 0.035) as independent predictors for AF recurrence. A combined clinical-imaging score [Left Atrial Geometry and Outcome (LAGO)] including five items (AF phenotype, structural heart disease, CHA2DS2-VASc ≤ 1, LAD, and LA sphericity) classified patients at low (≤2 points) and high risk (≥3 points) of procedural failure (35% vs. 82% recurrence at 3-year follow-up, respectively; HR 3.10, P < 0.001). Conclusion: In this multicentre, real-life cohort, LA sphericity and AF phenotype were the strongest predictors of AF ablation outcome after adjustment for covariates. The LAGO score was easy to implement, identified high risk of procedural failure, and could help select optimal candidates. Clinical Trial Registration Information: NCT02373982 (http://clinicaltrials.gov/ct2/show/NCT02373982).