Arrhythmia & Electrophysiology Review最新文献

There are many factors contributing to the failure of conventional CRT with biventricular pacing, including coronary anatomy and an inability to stimulate diseased tissue. In this paper, we review evolving conduction system pacing (CSP), a physiological alternative to conventional CRT. CSP allows correction of bundle branch block and provides new opportunities to address multiple limitations of conventional CRT. Further studies are required to determine how the techniques are best applied in specific clinical situations.

Background: This study compared the efficacy and safety of temperature-controlled and conventional contact-force-sensing radiofrequency ablation catheters for pulmonary vein isolation (PVI) in AF.

Methods: Seven studies (1,138 patients) were included. Randomised controlled trials and observational (single-arm and two-arm) studies that reported freedom from AF ≥3 months after PVI with temperature-controlled radiofrequency ablation catheters (Biosense Webster QDOT MICRO operating in QMODE or Medtronic DiamondTemp) were included.

Results: Freedom from AF at a mean (± SD) follow-up of 9.0 ± 3.6 months did not differ significantly between temperature-controlled and conventional ablation (OR 1.22; 95% CI [-0.79, 1.64]; p=0.24). Total procedure duration (-13.5 minutes; 95% CI [-17.1, -10.0 minutes]; p<0.001) and total ablation duration (-8.9 min; 95% CI [-10.3, -7.5 min]; p<0.01) were significantly shorter for temperature-controlled ablation. There were no significant differences between temperature-controlled and conventional ablation in either the aggregated rates of procedural complications (OR 0.69; 95% CI [-0.15, 1.54]; p=0.11) or in the rate of any individual complication.

Conclusion: Temperature-controlled ablation was found to be at least non-inferior to conventional ablation in all measures of efficacy and safety. Further randomised controlled trials are warranted to evaluate long-term rates of freedom from AF and patient comfort.

Background: Left ventricular systolic dysfunction (LVSD) can improve after catheter ablation (CA) in many patients with AF. However, prospective prediction of response can be challenging. The aim of this study was, therefore, to perform a systematic literature review of features associated with improvement in left ventricular ejection fraction (LVEF) in patients with AF and LVSD undergoing first CA.

Method: Systematic search of Ovid MEDLINE, Embase and Cochrane Library databases up to 24 January 2024, for studies involving adult patients with LVSD receiving treatment for AF. The focus was on research articles and clinical trials reporting features associated with changes in LVEF following CA. The review followed PRISMA guidelines.

Results: A total of 789 unique articles were reviewed and 20 were included in the systematic review. Sixty-nine per cent (range, 54-79%) of included patients met the criteria for responder status, which were based on LVEF improvement (usually an increase in LVEF >10% or to >50% at follow-up). Baseline surrogates of myocardial fibrosis on MRI (R²=-0.67), electroanatomical mapping (R²=-0.93) and biochemical surrogates have shown the strongest association with LVEF change. Left atrium and LV chamber size, diastolic dysfunction ECGbased parameters and a known heart failure aetiology have shown prognostic value independently and in combination.

Discussion: Imaging, clinical and ECG-based surrogates of LV fibrosis may be pre-CA markers of LVEF improvement in patients with AF and LVSD. However, the confounding effect of procedural outcomes should be considered. A composite risk stratification tool would have clinical utility in risk stratification and patient selection; however, prospective studies are needed.

Vasovagal syncope (VVS) is the most common cause of syncope, and significantly impacts quality of life despite its benign nature. For some patients, conventional management strategies such as lifestyle changes, pharmacotherapy and pacemaker implantation, fail to prevent recurrence. Cardioneuroablation (CNA), a novel intervention targeting the cardiac autonomic nervous system's ganglionated plexi, has shown promise in addressing refractory VVS. This review examines the therapeutic potential of CNA, exploring the anatomy and physiology of the cardiac autonomic nervous system, the role of ganglionated plexi in cardiac regulation and the rationale behind their selection as ablation targets. The review also discusses diverse strategies for ganglionated plexi identification and ablation. The gateway ganglionated plexi hypothesis is used to explain the success of CNA across varied procedural methods, despite the absence of a standardized technique. These gateway ganglionated plexi, located near the sinoatrial and atrioventricular nodes, potentially serve as central nodes influencing heart rhythm and rate, thus explaining the high success rates in VVS treatment using different approaches.

Functional substrate mapping has emerged as an essential tool for electrophysiologists, overcoming many limitations of conventional mapping techniques and demonstrating favourable long-term outcomes in clinical studies. However, a consensus on the definition of 'functional substrate' mapping remains elusive, hindering a structured approach to research in the field. In this review, we highlight the differences between 'functional mapping' techniques (which assess tissue response to the 'electrophysiological stress' using short coupled extrastimuli) and those highlighting regions of slow conduction during sinus rhythm. We also address fundamental questions, including the optimal degree of electrophysiological stress that best underpins the critical isthmus and the role of wavefront activation in determining the most effective ablation site.

In this review, we summarise the ongoing debate surrounding the anatomy of the atrioventricular conduction axis and its relevance to pacing. We highlight previous disagreements and emphasise the importance of understanding the anatomical location of the axis. We give credit and support to the initial descriptions by His and Tawara, in particular their attention to the relationship of the atrioventricular conduction axis with the membranous septum. We express our disagreements with recent diagrams that incorrectly, in our opinion, depict the left bundle and right bundle branches. We offer our own latest understanding of the location and relationships of the atrioventricular conduction axis, including details of its development, and differences between human and animal hearts. We also emphasise the importance of understanding the relationship between the inferior pyramidal space and the inferoseptal recess so as appropriately to place the axis within the heart. We conclude by emphasising the need to consider the heart in the context of the body, describing its component parts by using attitudinally appropriate nomenclature.

Permanent cardiac pacing in children with congenital complete atrioventricular block (CCAVB) and/or congenital heart disease (CHD) is challenging. Conduction system pacing (CSP) represents a novel pacing strategy aiming to preserve physiological ventricular activation. Patients with CCAVB or CHD are at high risk of developing pacing-induced cardiomyopathy with chronic conventional right ventricular myocardial pacing. CSP may be a valuable pacing modality in this particular setting because it can preserve ventricular synchrony. In this review, we summarise implantation techniques, the available clinical evidence and future directions related to CSP in CCAVB and CHD.

Background: AF is a common complication of an acute MI (AMI) and goes along with adverse events. Nevertheless, the therapeutical guidelines and pharmacological possibilities have improved over the past years. Therefore, this contemporary study aimed to clarify the effect of AF on long-term mortality in patients with incident AMI.

Methods: This study included 2,313 patients aged 25-84 years with initial AMI that occurred from 2009 until 2017, documented within the population-based Augsburg Myocardial Infarction Registry. Patients were monitored from hospital admission, with a median follow-up duration of 4.5 years (interquartile range 4.4 years). Survival analysis and multivariable Cox regression analysis were conducted to explore the relationship between AF and long-term all-cause and cardiovascular disease mortality.

Results: Altogether, 156 individuals had AF on their admission ECG, while the remaining 2,157 presented with sinus rhythm (SR). Patients with AF were significantly older, more frequently had arterial hypertension, non-ST-segment elevation MI, worse kidney function, smaller AMIs, and were more often former and non-smokers. An increased long-term all-cause mortality was observed among the AF group. (AF patients 39.1%, SR group 16.7%), Upon multivariable adjustment, a HR of 1.40 (95% CI [1.05-1.87]; p=0.023) was calculated when comparing the AF with SR patients.

Conclusion: An independently increased risk of long-term mortality for patients with AF compared with patients with SR in case of incident AMI was identified. Therefore, AF should be considered as a serious risk factor in AMI patients, and must be treated aggressively to reduce mortality risk.

Background: Extensive research has been devoted to ICDs, but there is still a significant gap in the literature regarding phantom shocks (PSs). Understanding the frequency, predictors, risk factors, management and health implications of PSs is essential. This review aimed to comprehensively investigate PSs in patients with ICDs up to the present day. Specifically, the review explores the incidence of PSs, identifies risk factors that may increase their likelihood and determines predictive factors to help anticipate their occurrence. By addressing these points, the study aimed to enhance the understanding and management of PSs in ICD patients.

Methods: This study reviewed central databases from their inception up to March 2024. The primary objective was to examine the occurrence of PSs in patients with ICDs. Data were gathered on patient demographics, incidence rates, and various risk factors and predictors that might affect the occurrence of PSs. Then, a detailed analysis of the collected data was conducted to identify significant associations between these risk factors, predictors and the incidence of PSs.

Results: This review identified a significant association between prior ICD shocks, defibrillation threshold testing, the presence of depression and anxiety for the occurrence of PS in patients with ICDs. This underscores the importance of thoroughly evaluating and managing these factors to improve the care of individuals with ICDs.

Conclusion: PSs are often associated with various factors, such as previous shock therapy, defibrillation threshold testing, depression, anxiety and higher levels of education. It is crucial for healthcare providers to acknowledge these correlations and provide personalised care to patients experiencing PSs.

During catheter ablation of post-infarct ventricular tachycardia (VT), substrate mapping is used when VT is non-inducible or poorly tolerated. Substrate mapping aims to identify regions of slowly conducting myocardium (borderzone) within and surrounding myocardial scar for ablation. Historically, these tissue types have been identified using bipolar voltage mapping, with areas of low bipolar voltage (<0.50 mV) defined as scar, and areas with voltages between 0.50 mV and 1.50 mV as borderzone. In the era of high-density mapping, studies have demonstrated slow conduction within areas of bipolar voltage <0.50 mV, suggesting that this historical cut-off is outdated. While electrophysiologists often adapt voltage cut-offs to account for this, the optimal scar-borderzone threshold is not known. In this review, we discuss dynamic voltage mapping, a novel substrate mapping technique we have developed, which superimposes data from both activation and voltage maps, to help delineate the post-infarct VT circuit through identification of the optimal scar-borderzone voltage threshold.