Heart Rhythm O2最新文献

Ventricular tachycardia (VT) is a life-threatening heart rhythm and has long posed a complex challenge in the field of cardiology. Recent developments in advanced imaging modalities have aimed to improve comprehension of underlying arrhythmic substrate for VT. To this extent, high-resolution cardiac magnetic resonance (CMR) and cardiac computed tomography (CCT) have emerged as tools for accurately visualizing and characterizing scar tissue, fibrosis, and other critical structural abnormalities within the heart, providing novel insights into VT triggers and substrate. However, clinical implementation of knowledge derived from these advanced imaging techniques in improving VT treatment and guiding invasive therapeutic strategies continues to pose significant challenges. A pivotal concern lies in the absence of standardized imaging protocols and analysis methodologies, resulting in a large variance in data quality and consistency. Furthermore, the clinical significance and outcomes associated with VT substrate characterization through CMR and CCT remain dynamic and subject to ongoing evolution. This highlights the need for refinement of these techniques before their reliable integration into routine patient care can be realized. The primary objectives of this study are twofold: firstly, to provide a comprehensive overview of the studies conducted over the last 15 years, summarizing the current available literature on imaging-based assessment of VT substrate. Secondly, to critically analyze and evaluate the selected studies, with the aim of providing valuable insights that can inform current clinical practice and future research.

Background

Atrioventricular nodal re-entrant tachycardia (AVNRT) is the most common paroxysmal supraventricular tachycardia. We sought to investigate the incidence of atrial fibrillation in patients with electrophysiologically confirmed/ablated AVNRT and its association with transient ischemic attack (TIA)/stroke as well as mortality during long-term follow-up.

Methods

From the Karolinska Ablation Registry, 2855 consecutive patients with a first-time ablation for AVNRT between 2005 and 2018 were analyzed.

Results

Patients were 52.1 ± 15.9 years old and 59.3% were women. During follow-up of up to 10 years (median 6.0 years; interquartile range 3.3 to 9.2 years), new onset or recurrence of atrial fibrillation occurred in 317 (11.1%) patients (incidence rate 19 cases per 1000 person-years). Excluding those with history of atrial fibrillation, new onset of atrial fibrillation occurred in 153 (6.1%) patients. In multivariable analysis, history of atrial fibrillation, arterial hypertension, history of TIA/stroke, and heart failure remained independently associated with new onset or recurrence of atrial fibrillation during follow-up. Death of any cause and TIA/stroke occurred in 141 (4.9%) patients and 107 (3.7%) patients, respectively. In multivariable analysis, occurrence of atrial fibrillation during follow-up remained independently associated with both outcomes. The prevalence of atrial fibrillation according to age at the end of follow-up was high among young patients (<60 years of age: 12.7%; 60–69 years of age: 10.6%).

Conclusion

In this large cohort of patients with diagnosed AVNRT, the incidence of atrial fibrillation was high (11.1%) during long-term follow-up. Occurrence of atrial fibrillation during follow-up remained independently associated with death for any cause as well as with TIA/stroke. Therefore, a closer monitoring for atrial fibrillation in patients with AVNRT including those at young age is advisable.

Background

Long QT syndrome (LQTS) is a rare cardiac disorder characterized by prolonged ventricular repolarization and increased risk of ventricular arrhythmias. This review summarizes current knowledge of LQTS pathogenesis and treatment strategies.

Objectives

The purpose of this study was to provide an in-depth understanding of LQTS genetic and molecular mechanisms, discuss clinical presentation and diagnosis, evaluate treatment options, and highlight future research directions.

Methods

A systematic search of PubMed, Embase, and Cochrane Library databases was conducted to identify relevant studies published up to April 2024.

Results

LQTS involves mutations in ion channel–related genes encoding cardiac ion channels, regulatory proteins, and other associated factors, leading to altered cellular electrophysiology. Acquired causes can also contribute. Diagnosis relies on clinical history, electrocardiographic findings, and genetic testing. Treatment strategies include lifestyle modifications, β-blockers, potassium channel openers, device therapy, and surgical interventions.

Conclusion

Advances in understanding LQTS have improved diagnosis and personalized treatment approaches. Challenges remain in risk stratification and management of certain patient subgroups. Future research should focus on developing novel pharmacological agents, refining device technologies, and conducting large-scale clinical trials. Increased awareness and education are crucial for early detection and appropriate management of LQTS.

Background

Different energy sources of balloon-based ablation for pulmonary vein isolation cause different kinds of endothelial damage and coagulation responses associated with thromboembolic risk.

Objectives

The study sought to compare the impact of different balloon-based ablation, cryoballoon ablation (CBA) and laser balloon ablation (LBA), on coagulation/fibrinolysis biomarkers and silent cerebral events (SCEs) in paroxysmal atrial fibrillation.

Methods

Paroxysmal atrial fibrillation patients who underwent pulmonary vein isolation using either CBA (n = 52) or LBA (n = 53) without radiofrequency touch-up ablation were eligible. Time course (day 0 [before ablation], day 1, day 2, and day 28) of myocardial enzymes and inflammatory and coagulation/fibrinolysis biomarkers was evaluated during the perioperative period. Brain magnetic resonance imaging was performed within 2 days after the procedure to evaluate SCEs.

Results

There was no difference in patient characteristics between CBA and LBA.CBA had greater myocardial injury (troponin I and creatine kinase-MB) and lower inflammatory reaction (white blood cell count and neutrophil/lymphocyte ratio) than LBA. The coagulation biomarkers maximally increased by day 2 and then decreased in both groups. In day 28, the serum prothrombin fragment 1+2 and D-dimer levels in LBA were significantly higher than the values in CBA. The fibrinolysis biomarker (plasmin-α2 plasmin inhibitor complex) did not increase after the procedure in either group. The incidence of SCEs was comparable between CBA and LBA (11% vs 15%; P = .591). No thromboembolic event was observed.

Conclusion

CBA and LBA had different effects on myocardial injury, inflammatory reaction, and coagulation activity but did not affect the incidence of thromboembolic events. LBA had significantly higher coagulation activity in day 28 and may require more careful postprocedural anticoagulation than CBA.

Background

Leadless cardiac resynchronization therapy (CRT) is an emerging heart failure treatment. An implanted electrode delivers lateral or septal endocardial left ventricular (LV) pacing (LVP) upon detection of a right ventricular (RV) pacing stimulus from a coimplanted device, thus generating biventricular pacing (BiVP). Electrical efficacy data regarding this therapy, particularly leadless LV septal pacing (LVSP) for potential conduction system capture, are limited.

Objectives

The purpose of this study was to evaluate the acute performance of leadless CRT using electrocardiographic imaging (ECGi) and assess the optimal pacing modality (OPM) of LVSP on the basis of RV and LV activation.

Methods

Ten WiSE-CRT recipients underwent an ECGi study testing: RV pacing, BiVP, LVP only, and LVP with an optimized atrioventricular delay (LV-OPT). BiV, LV, and RV activation times (shortest time taken to activate 90% of the ventricles [BIVAT-90], shortest time taken to activate 95% of the LV, and shortest time taken to activate 90% of the RV) plus LV and BiV dyssynchrony index (standard deviation of LV activation times and standard deviation of all activation times) were calculated from reconstructed epicardial electrograms. The individual OPM yielding the greatest improvement from baseline was determined.

Results

BiVP generated a 23.7% improvement in BiVAT-90 (P = .002). An improvement of 43.3% was observed at the OPM (P = .0001), primarily through reductions in shortest time taken to activate 90% of the RV. At the OPM, BiVAT-90 improved in patients with lateral (43.3%; P = .0001; n = 5) and septal (42.4%; P = .009; n = 5) LV implants. The OPM varied by individual. LVP and LV-OPT were mostly superior in patients with LVSP, and in those with sinus rhythm and left bundle branch block (n = 4).

Conclusion

Leadless CRT significantly improves acute ECGi-derived activation and dyssynchrony metrics. Using an individualized OPM improves efficacy in selected patients. Effective LVSP is feasible, with fusion pacing at LV-OPT mitigating the potential deleterious effects on RV activation.

Background

Electrogram dispersion identifies putative atrial fibrillation (AF) drivers in first time ablation procedures, with high acute termination rates and long-term outcomes akin to extensive ablation approaches. Its use in a population that had undergone repeat ablation is unknown, particularly where the pulmonary veins are already isolated.

Objective

This purpose of this study was to assess electrogram dispersion mapping during repeat ablation procedures for persistent AF.

Methods

One hundred sixty-seven patients from the United Kingdom and Denmark, all with persistent AF recurrence after prior ablation procedure(s), were mapped using a five splined catheter for electrogram dispersion before ablation. Areas were manually tagged on biatrial electroanatomic maps and ablated once pulmonary vein isolation was confirmed or reisolated if required. All patients had 12-month continuous monitoring, with most of the cohort having follow-up beyond 24 months.

Results

Of the 167 patients [53 (32%) female; mean age 66 ± 8 years; mean left atrial (LA) diameter 4.8 cm; mean ejection fraction 53%], 108 had pulmonary veins already isolated. Dispersion sites occurred in both atria (3.2 LA, 1.4 right atrium). Acute termination to sinus rhythm occurred in 71 (42%) of the cohort patients, with a further 73 (44%) terminating to atrial tachycardia/flutter. At 12-month follow-up, 95% of patients were free of AF, with 74% overall freedom from all atrial arrhythmias. Heart failure and severely enlarged LA predicted recurrence, and termination to sinus improved freedom from all atrial arrhythmias.

Conclusion

Dispersion mapping is a promising approach at repeat ablation procedures for persistent AF, with high acute termination rates and good clinical outcomes. Further prospective randomized trials are needed to evaluate this approach in a population that had undergone repeat ablation.