Arrhythmia & Electrophysiology Review最新文献

Late gadolinium enhancement (LGE) MRI is capable of detecting not only native cardiac fibrosis, but also ablation-induced scarring. Thus, it offers the unique opportunity to assess ablation lesions non-invasively. In the atrium, LGE-MRI has been shown to accurately detect and localise gaps in ablation lines. With a negative predictive value close to 100% it can reliably rule out pulmonary vein reconnection non-invasively and thus may avoid unnecessary invasive repeat procedures where a pulmonary vein isolation only approach is pursued. Even LGE-MRI-guided repeat pulmonary vein isolation has been demonstrated to be feasible as a standalone approach. LGE-MRI-based lesion assessment may also be of value to evaluate the efficacy of ventricular ablation. In this respect, the elimination of LGE-MRI-detected arrhythmogenic substrate may serve as a potential endpoint, but validation in clinical studies is lacking. Despite holding great promise, the widespread use of LGE-MRI is still limited by the absence of standardised protocols for image acquisition and post-processing. In particular, reproducibility across different centres is impeded by inconsistent thresholds and internal references to define fibrosis. Thus, uniform methodological and analytical standards are warranted to foster a broader implementation in clinical practice.

The success of radiofrequency catheter ablation of the accessory pathway (AP) depends on the accurate localisation of the bypass tract. In that respect, posteroseptal or inferior paraseptal APs often pose a diagnostic challenge because of the complex anatomy at the crux of the four cardiac chambers. Considering the differences in procedure risks and success rate depending on the need for a left-sided approach or a coronary sinus ablation, an accurate anticipation of the precise location of inferior paraseptal APs is critical to inform the consent process and guide the initial mapping strategy. Here, the preprocedural clues to discriminate APs that can be ablated from the right atrium, from those requiring a left-sided or epicardial coronary venous approach, are reviewed. Both manifest and concealed APs will be considered and, following the diagnostic process made by the operator before interpretation of the intra-cardiac signals, each of the following aspects will be addressed: clinical context and initial probability; and 12-lead ECG analysis during baseline ECG with manifest AP, maximal preexcitation, and orthodromic reciprocating tachycardia.

Up to 65% of patients with heart failure with preserved ejection fraction (HFpEF) develop AF during the course of the disease. This occurrence is associated with adverse outcomes, including pump failure death. Because AF and HFpEF are mutually reinforcing risk factors, sinus rhythm restoration may represent a disease-modifying intervention. While catheter ablation exhibits acceptable safety and efficacy profiles, no randomised trials have compared AF ablation with medical management in HFpEF. However, catheter ablation has been reported to result in lower natriuretic peptides, lower filling pressures, greater peak cardiac output and improved functional capacity in HFpEF. There is growing evidence that catheter ablation may reduce HFpEF severity, hospitalisation and mortality compared to medical management. Based on indirect evidence, early catheter ablation and minimally extensive atrial injury should be favoured. Hence, individualised ablation strategies stratified by stepwise substrate inducibility provide a logical basis for catheter-based rhythm control in this heterogenous population. Randomised trials are needed for definitive evidence-based guidelines.

The majority of patients tolerate right ventricular pacing well; however, some patients manifest signs of heart failure after pacemaker implantation and develop pacing-induced cardiomyopathy. This is a consequence of non-physiological ventricular activation bypassing the conduction system. Ventricular dyssynchrony was identified as one of the main factors responsible for pacing-induced cardiomyopathy development. Currently, methods that would allow rapid and reliable ventricular dyssynchrony assessment, ideally during the implant procedure, are lacking. Paced QRS duration is an imperfect marker of dyssynchrony, and methods based on body surface mapping, electrocardiographic imaging or echocardiography are laborious and time-consuming, and can be difficult to use during the implantation procedure. However, the ventricular activation sequence can be readily displayed from the chest leads using an ultra-high-frequency ECG. It can be performed during the implantation procedure to visualise ventricular depolarisation and resultant ventricular dyssynchrony during pacing. This information can assist the electrophysiologist in selecting a pacing location that avoids dyssynchronous ventricular activation.

Injury to structures adjacent to the heart, particularly oesophageal injury, accounts for a large proportion of fatal and life-altering complications of ablation for persistent AF. Avoiding these complications dictates many aspects of the way ablation is performed. Because avoidance involves limiting energy delivery in areas of interest, fear of extracardiac injury can impede the ability of the operator to perform an effective procedure. New techniques are becoming available that may permit the operator to circumvent this dilemma and deliver effective ablation with less risk to adjacent structures. The authors review all methods available to avoid injury to extracardiac structures to put these developments in context.

Randomised evidence supports an early rhythm control strategy as treatment for AF, and catheter ablation outperforms medical therapy in terms of effectiveness when studied as first- and second-line treatment. Despite evidence consistently showing that catheter ablation treatment is superior to medical therapy in most AF patients, only a small proportion receive ablation, in some cases after a prolonged trial of ineffective medical therapy. Health economics research in electrophysiology remains limited but is recognised as being important in influencing positive change to ensure early access to ablation services for all eligible patients. Such information has informed the updated recommendations from the recently published National Institute for Health and Care Excellence clinical guideline on the diagnosis and management of AF, but increased awareness is needed to drive real-world adoption and to ensure patients are quickly referred to specialists. In this article, economic evaluations of catheter ablation versus medical therapy are reviewed.

This review sets out the key evidence comparing subcutaneous ICDs (S-ICDs) and transvenous ICDs and uses it to empower clinical cardiologists and those who implant ICDs to make optimum patient selections for S-ICD use. The evidence demonstrates that clinical trials performed until recently have proven the performance of S-ICDs. However, the latest data now available from the ATLAS randomised controlled trial have added new insights to this body of evidence. ATLAS demonstrates the superiority of S-ICDs over transvenous ICDs regarding lead-related complications, findings that point to promising opportunities for patients who are at risk of sudden cardiac death.

The name Ivan Mahaim is well-known to electrophysiologists. However, alternative anatomical substrates can produce the abnormal rhythms initially interpreted on the basis of the pathways he first described. These facts have prompted suggestions that Mahaim should be deprived of his eponym. It is agreed that specificity is required when describing the pathways that produce the disordered cardiac conduction, and that the identified pathways should now be described in an attitudinally appropriate fashion. The authors remain to be convinced that understanding will be enhanced simply by discarding the term 'Mahaim physiology' from the lexicon. It is fascinating to look back at the history of accessory atrioventricular junctional conduction pathways outside the normal accessory atrioventricular conduction system, and their possible role in rhythm disturbances. It took both the anatomist and the clinical arrhythmologist quite some time to understand the complex anatomical architecture and the ensuing electrophysiological properties. Over the years, the name Mahaim was often mentioned in those discussions, although these pathways were not the ones that produced the eponym. The reason for this review, therefore, is to present relevant information about the person and what followed thereafter.

AF is the most common cardiac arrhythmia and has been identified as an independent risk factor for stroke. The European Society of Cardiology guidelines recommend a thromboembolic event risk assessment based on the CHA₂DS₂-VASc score. However, stroke also occurs in some patients with a low CHA₂DS₂-VASc score. Therefore, it is necessary to find new factors to improve thromboembolic risk stratification in AF patients. Over 90% of embolic strokes are caused by thrombi originating from the left atrial appendage (LAA). Thus, certain anatomical or functional parameters of the LAA could potentially be used to predict cardioembolic stroke. Studies have suggested that some of these factors, such as LAA morphology, number of LAA lobes, LAA dimensions, LAA volume, distance from the LAA ostium to the first bend of LAA, LAA orifice diameter, extent of LAA trabeculations, LAA takeoff, LAA flow velocity and LAA strain rate, are independently associated with a higher risk of stroke in a population of patients with AF and improve the performance of the CHA₂DS₂-VASc score. However, the results are conflicting and, so far, no new parameter has been added to the CHA₂DS₂-VASc score.