Arrhythmia & Electrophysiology Review最新文献

Conduction system pacing, particularly left bundle branch area pacing (LBBAP), has become a popular form of lead implantation for patients with ventricular pacing indications. Success rates are reportedly high, and complication rates are relatively low. However, complications with LBBAP are unique and follow-up and troubleshooting need to be more meticulous. This paper reviews some of the short- and longer-term complications that one may see with LBBAP. Guidance on device programming, follow-up and tips on troubleshooting for LBBAP is also provided.

Background: Elevated CHA₂DS₂-VASc scores are considered to be predictors of left atrial appendage (LAA) thrombus (LAAT); however, individuals with low scores remain at risk. Studies have indicated that aortic atherosclerosis (AA) is associated with increased stroke risk. AA on transoesophageal echocardiography (TOE) has been overlooked as a 'vascular' variable in the CHA₂DS₂-VASc score.

Aims: Determine the prevalence of LAAT in patients with low thromboembolic risk and the correlation of AA with LAAT.

Methods: We performed a retrospective review of all TOEs performed for patients who underwent electrophysiology procedures at the McGill University Health Centre from 2012 to 2017 and collected pertinent clinical and echocardiography variables. We reviewed all TOEs to evaluate the presence and severity of AA using the Katz score, American Society of Echocardiography (ASE) grade and the Ferrari score. In patients with a CHADS₂ of 0 and CHA₂DS₂-VASc score of ≤1, logistical regression and receiver operating characteristic curves were used to identify predictors for LAAT.

Results: 592 patients underwent a pre-procedure TOE and were included in the analysis. Among 249 patients with CHA₂DS₂-VASc scores ≤1, 7.5% had LAA. AA burden by Katz score was an independent predictor of LAAT (area under the curve (AUC) 0.76 95% CI [0.60-0.92]) for CHA₂DS₂-VASc ≤1.

Conclusion: AA visualised on TOE was significantly associated with an increased risk of LAAT development in patients with low CHA₂DS₂-VASc scores. Incorporating AA assessment into risk stratification may enhance clinical decision-making for the use of anticoagulation for patients with AF. Future studies are warranted to evaluate the use of other imaging modalities for AA detection.

Sudden cardiac death (SCD) is one of the leading causes of death worldwide. Coronary artery disease (CAD) is the predominant cause of SCD in older individuals, while inherited cardiomyopathies and channelopathies are more common in younger individuals under the age of 35 years. Genetic disorders associated with SCD have traditionally been perceived as monogenic disorders. However, increasing evidence suggests that many of these disorders have complex genetic architecture with contributions from multiple genetic variants, known as polygenic inheritance, along with environmental factors. Improved understanding of genetic contributions and variants in SCD may help elucidate the cause of SCD, enable risk stratification, and identify novel disease mechanisms to guide preventative and therapeutic strategies in SCD. This review provides an overview of the genetic risk factors and clinical implications for the most common cardiac disorders related to SCD in both old and young individuals: specifically CAD, as well as the inherited cardiomyopathies and channelopathies, respectively.

Background: Myocardial connections of left ventricular (LV) papillary muscles (PM) are determinants of QRS variability in the case of PM arrhythmias. We investigated the anatomical substrate of monomorphic versus polymorphic LV PM arrhythmias in patients with apparently normal hearts, as well as ablation outcomes.

Methods: Thirty-two patients were eligible for analysis. Thirteen patients underwent ablation. With advanced cardiac imaging (cardiac MRI or multidetector CT), we determined the number of PM-PM and PM-surrounding myocardium connections, PM architecture according to the number of strands and the level of LV trabeculation.

Results: Combinations of unifocal (monomorphic premature ventricular complexes [PVCs]), multiform PVCs and/or runs of polymorphic PM arrhythmias (≥3 beats) were recorded in 24 patients. The remaining eight patients had only unifocal monomorphic PVCs. The mean [± SD] number of PM connections was higher than that of PM-PM or PM-myocardial connections in patients with multiform PVCs (30 ± 1.5 versus 4 ± 1, respectively) or polymorphic arrhythmias (136 ± 4 versus 26 ± 3, respectively; p=0.004). Compared with the unifocal group, the frequency of multistranded PMs was higher (1 versus 22, respectively; p<0.001) and LV trabeculation was more pronounced in the group with multiform arrhythmia (multiform PVCs and/or polymorphic arrhythmias). All patients ablated for unifocal PVCs remained free of recurrence, compared with only half of those ablated for multiform PVCs.

Conclusion: Patients with multiform PM arrhythmias have more PM connections, PM strands and trabeculation than patients without QRS variability. The long-term effectiveness of catheter ablation in this patient group is limited.

Cardioneuroablation is a relatively new method to treat asystolic reflex syncope. The short- and mid-term efficacy ranges between 70% and 94%. Although the method is increasingly used worldwide, there are many unresolved issues associated with the use of this technique. One such issue is the correct identification of optimal candidates for cardioneuroablation. This article reviews the demographic, clinical and procedural parameters that may be of value in predicting the efficacy of cardioneuroablation.

Fasciculoventricular accessory pathways (FVAPs), once considered rare variants of pre-excitation syndrome, are now recognised as ubiquitous in both humans and murine. Nonetheless, most FVAPs are likely electrically silent. However, they can become evident, as reported for some glycogen storage diseases (such as Danon disease and PRKAG2) and during high-voltage septal pacing. Typically, FVAPs only exhibit antegrade and non-decremental conducting properties. A block at the FVAP results in a normal His-to-ventricle interval and a narrow QRS complex without signs of pre-excitation. Decremental conduction over FVAP was once reported in a setting of PRKAG2 mutation. However, in the present case, incremental atrial pacing revealed varying His-to-ventricle intervals, with functional decremental conduction that was accompanied by varied QRS morphologies. These findings underscore the diagnostic challenges posed by FVAPs, and highlight the need for meticulous electrophysiological assessment to accurately distinguish them from other pre-excitation syndromes. This case exemplifies the nuanced behaviour of FVAPs, emphasising their clinical and diagnostic complexity in electrophysiological practice.

Objectives: The occurrence of new conduction abnormalities necessitating permanent pacemaker implantation (PPI) is a complication of transcatheter aortic valve replacement (TAVR). Previous studies have shown inconsistent results about the clinical impact of new PPI after TAVR.

Methods: CONDUCT was a prospective observational registry that enrolled 295 patients undergoing TAVR at four European centres. The primary goal of this registry was to compare 1-year clinical outcomes in TAVR patients with or without PPI, using one-to-four propensity score matched (PSM) analysis. It also assessed major adverse cardiac events (MACE) in patients undergoing right ventricular pacing after PPI.

Results: Out of 160 PSM patients, 36 underwent PPI and the other 124 had no PPI within 30 days post-TAVR. The median age of the patients was 80 years, with more men (80.6% and 84.7% in patients with and without PPI, respectively) and similar EuroSCORE II and Society of Thoracic Surgeons scores. Patients with PPI had higher diabetes prevalence (p=0.055) and lower left ventricular ejection fraction percentages (p=0.034), but higher systolic pulmonary artery pressure (p=0.013) than those without PPI. However, these differences diminished after PSM. At 1 year, PPI patients had a nonsignificant but slightly higher incidence of MACE (22.2% versus 13.7%; p=0.216) (HR 1.63; 95% CI [0.72-3.71]) driven by increased heart failure (11.1% versus 2.4%; p=0.046) (HR 5.05; 95% CI [1.09-23.4]). Freedom from all-cause mortality, cardiovascular death, stroke and endocarditis at 1-year follow-up was comparable between groups.

Conclusion: Despite a higher incidence of congestive heart failure rehospitalisation in patients undergoing PPI, 1-year clinical outcomes were similar in both groups.

Inappropriate sinus tachycardia (IST) is a clinical syndrome that generally affects young patients and is associated with distressing symptoms. Cardioneuroablation (CNA) is a promising method for the treatment of asystolic reflex syncope, functional bradycardia or atrioventricular block. Because CNA involves parasympathetic denervation, one potential adverse effect may be IST. We present an educational case of a patient with mixed vasovagal syncope and symptomatic sinus bradycardia who underwent CNA, as a result of which bradycardia converted to IST and the patient required subsequent pacemaker implantation. We also review the incidence of IST after CNA and difficulties around the definition and treatment of post-CNA IST.