Personalized pulmonary vein isolation with very high-power short-duration lesions guided by left atrial wall thickness: the QDOT-by-LAWT randomized trial.

AIMS: Pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (PAF) using very high-power short-duration (vHPSD) radiofrequency (RF) ablation proved to be safe and effective. However, vHPSD applications result in shallower lesions that might not be always transmural. Multidetector computed tomography-derived left atrial wall thickness (LAWT) maps could enable a thickness-guided switching from vHPSD to the standard-power ablation mode. The aim of this randomized trial was to compare the safety, the efficacy, and the efficiency of a LAWT-guided vHPSD PVI approach with those of the CLOSE protocol for PAF ablation (NCT04298177). METHODS AND RESULTS: Consecutive patients referred for first-time PAF ablation were randomized on a 1:1 basis. In the QDOT-by-LAWT arm, for LAWT ≤2.5 mm, vHPSD ablation was performed; for points with LAWT > 2.5 mm, standard-power RF ablation titrating ablation index (AI) according to the local LAWT was performed. In the CLOSE arm, LAWT information was not available to the operator; ablation was performed according to the CLOSE study settings: AI ≥400 at the posterior wall and ≥550 at the anterior wall. A total of 162 patients were included. In the QDOT-by-LAWT group, a significant reduction in procedure time (40 vs. 70 min; P < 0.001) and RF time (6.6 vs. 25.7 min; P < 0.001) was observed. No difference was observed between the groups regarding complication rate (P = 0.99) and first-pass isolation (P = 0.99). At 12-month follow-up, no significant differences occurred in atrial arrhythmia-free survival between groups (P = 0.88). CONCLUSION: LAWT-guided PVI combining vHPSD and standard-power ablation is not inferior to the CLOSE protocol in terms of 1-year atrial arrhythmia-free survival and demonstrated a reduction in procedural and RF times.

Scar architecture affects the electrophysiological characteristics of induced ventricular arrhythmias in hypertrophic cardiomyopathy.

AIMS: Late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) detects myocardial scarring, a risk factor for ventricular arrhythmias (VAs) in hypertrophic cardiomyopathy (HCM). The LGE-CMR distinguishes core, borderzone (BZ) fibrosis, and BZ channels, crucial components of re-entry circuits. We studied how scar architecture affects inducibility and electrophysiological traits of VA in HCM. METHODS AND RESULTS: We correlated scar composition with programmed ventricular stimulation-inducible VA features using LGE intensity maps. Thirty consecutive patients were enrolled. Thirteen (43%) were non-inducible, 6 (20%) had inducible non-sustained, and 11 (37%) had inducible sustained mono (MMVT)- or polymorphic VT/VF (PVT/VF). Of 17 induced VA, 13 (76%) were MMVT that either ended spontaneously, persisted as sustained monomorphic, or degenerated into PVT/VF. Twenty-seven patients (90%) had LGE. Of these, 17 (57%) had non-sustained or sustained inducible VA. Scar mass significantly increased (P = 0.002) from non-inducible to inducible non-sustained and sustained VA patients in both the BZ and core components. Borderzone channels were found in 23%, 67%, and 91% of non-inducible, inducible non-sustained, and inducible sustained VA patients (P = 0.003). All 13 patients induced with MMVT or monomorphic-initiated PVT/VF had LGE. The origin of 10/13 of these VTs matched scar location, with 8/10 of these LGE regions showing BZ channels. During follow-up (20 months, interquartile range: 7-37), one patient with BZ channels and inducible PVT had an ICD shock for VF. CONCLUSION: Scar architecture determines inducibility and electrophysiological traits of VA in HCM. Larger studies should explore the role of complex LGE patterns in refining risk assessment in HCM patients.

Assessing left atrial intramyocardial fat infiltration from computerized tomography angiography in patients with atrial fibrillation.

AIMS: Epicardial adipose tissue might promote atrial fibrillation (AF) in several ways, including infiltrating the underlying atrial myocardium. However, the role of this potential mechanism has been poorly investigated. The aim of this study is to evaluate the presence of left atrial (LA) infiltrated adipose tissue (inFAT) by analysing multi-detector computer tomography (MDCT)-derived three-dimensional (3D) fat infiltration maps and to compare the extent of LA inFAT between patients without AF history, with paroxysmal, and with persistent AF. METHODS AND RESULTS: Sixty consecutive patients with AF diagnosis (30 persistent and 30 paroxysmal) were enrolled and compared with 20 age-matched control; MDCT-derived images were post-processed to obtain 3D LA inFAT maps for all patients. Volume (mL) and mean signal intensities [(Hounsfield Units (HU)] of inFAT (HU -194; -5), dense inFAT (HU -194; -50), and fat-myocardial admixture (HU -50; -5) were automatically computed by the software. inFAT volume was significantly different across the three groups (P = 0.009), with post-hoc pairwise comparisons showing a significant increase in inFAT volume in persistent AF compared to controls (P = 0.006). Dense inFAT retained a significant difference also after correcting for body mass index (P = 0.028). In addition, more negative inFAT radiodensity values were found in AF patients. Regional distribution analysis showed a significantly higher regional distribution of LA inFAT at left and right superior pulmonary vein antra in AF patients. CONCLUSION: Persistent forms of AF are associated with greater degree of LA intramyocardial adipose infiltration, independently of body mass index. Compared to controls, AF patients present higher LA inFAT volume at left and right superior pulmonary vein antra.

Catheter-induced right bundle branch block: Practical implications for the cardiac electrophysiologist.

The right bundle branch (RBB), due to its endocardial course, is susceptible to traumatic block caused by "bumping" during right-heart catheterization. In the era of cardiac electrophysiology, catheter-induced RBB block (CI-RBBB) has become a common phenomenon observed during electrophysiological studies and catheter ablation procedures. While typically transient, it may persist for the entire procedure time. Compared to pre-existing RBBB, the transient nature of CI-RBBB allows for comparative analysis relative to the baseline rhythm. Furthermore, unlike functional RBBB, it occurs at similar heart rates, making the comparison of conduction intervals more reliable. While CI-RBBB can provide valuable diagnostic information in various conditions, it is often overlooked by cardiac electrophysiologists. Though it is usually a benign and self-limiting conduction defect, it may occasionally lead to diagnostic difficulties, pitfalls, or undesired consequences. Avoidance of CI-RBBB is advised in the presence of baseline complete left bundle branch block and when approaching arrhythmic substrates linked to the right His-Purkinje-System, such as fasciculo-ventricular pathways, bundle branch reentry, and right-Purkinje focal ventricular arrhythmias. This article aims to provide a comprehensive practical review of the electrophysiological phenomena related to CI-RBBB and its impact on the intrinsic conduction system and various arrhythmic substrates.

How much does the presentation pattern of atrial fibrillation affect thrombo-embolic risk and mortality?

Atrial fibrillation (AF) is associated with a substantial increase in mortality and morbidity. Systemic thrombo-embolism is the most serious complication associated with this arrhythmia. The use of anticoagulant drugs is the cornerstone of therapy for the prophylaxis of stroke and peripheral ischaemia in these patients. The current guidelines recommend the use of anticoagulant drugs based on the thrombo-embolic risk profile of each individual patient calculated by SCORE based on the presence or absence of clinical risk factors and regardless of the presentation pattern of AF. A review of literature data investigating the effect of AF presentation pattern on thrombo-embolic risk and mortality showed an increased risk of both thrombo-embolic events and death in patients with non-paroxysmal AF compared to patients with paroxysmal AF. Most of these studies, however, consist of post-hoc analyses of large trials or observational studies and meta-analyses derived from these, resulting in an important limitation in the interpretation of data derived from such studies. At the same time, these data suggest the need for both new therapies to prevent AF progression and for further studies to explore the integration of AF presentation pattern into models of thrombo-embolic risk.

A Single-lead ECG algorithm to differentiate right from left manifest accessory pathways: A reappraisal of the P-Delta interval.

INTRODUCTION: Despite numerous ECG algorithms being developed to localize the site of manifest accessory pathways (AP), they often require stepwise multiple-lead analysis with variable accuracy, limitations, and reproducibility. The study aimed to develop a single-lead ECG algorithm incorporating the P-Delta interval (PDI) as an adjunct criterion to discriminate between right and left manifest AP. METHODS: Consecutive WPW patients undergoing electrophysiological study (EPS) were retrospectively recruited and split into a derivation and validation group (1:1 ratio). Sinus rhythm ECG analysis in lead V1 was performed by three independent investigators blinded to the EPS results. Conventional ECG parameters and PDI were assessed through the global cohort. RESULTS: A total of 140 WPW patients were included (70 for each group). A score-based, single-lead ECG algorithm was developed through derivation analysis incorporating the PDI, R/S ratio, and QRS onset polarity in lead V1. The validation group analysis confirmed the proposed algorithm's high accuracy (95%), which was superior to the previous ones in predicting the AP side (p < 0.05). A score of ≤+1 was 96.5% accurate in predicting right AP while a score of ≥+2 was 92.5% accurate in predicting left AP. The new algorithm maintained optimal performance in specific subgroups of the global cohort showing an accuracy rate of 90%, 92%, and 96% in minimal pre-excitation, posteroseptal AP, and pediatric patients, respectively. CONCLUSIONS: A novel single-lead ECG algorithm incorporating the PDI interval with previous conventional criteria showed high accuracy in differentiating right from left manifest AP comprising pediatric and minimal pre-excitation subgroups in the current study.

Chiari network for the interventional cardiologist: A hidden enemy at the heart gate - A systematic review of the literature.

BACKGROUND: This study aimed to collect and analyze the literature data regarding Chiari network (CN) and other right atrium (RA) remnants comprising the Eustachian and Thebesian valves (EV, ThV) as a potential entrapment site during different percutaneous cardiac procedures (PCP). METHODS AND RESULTS: A systematic search was conducted using Pubmed and Embase databases following the PRISMA guidelines to obtain available data concerning PCP associated with entrapment of inserted materials within CN-EV-ThV. The final analysis included 41 patients who underwent PCP with reported material entrapment within these RA remnants. The PCP was atrial septal defect (ASD)/patent foramen ovale (PFO) closure, catheter ablation, and pacemaker/defibrillator implantation in 44%, 22%, and 17% of patients, respectively. The entrapped materials were ASD/PFO devices, multipolar electrophysiology catheters, passive-fixation pacing leads, and J-guidewires in about 30%, 20%, 15%, and 10% of patients, respectively. Intraprocedural transthoracic, transoesophageal and intracardiac echocardiography showed sensitivity to reveal these structures of 20%, ∼95%, and 100%, respectively. A percutaneous approach successfully managed 70% of patients, while cardiovascular surgery was required in 20% and three patients died (7.3%). CONCLUSIONS: CN and other RA remnants may cause entrapment of various devices or catheters during PCP requiring right heart access. The percutaneous approach, guided by intraprocedural imaging, appears safe and effective in managing most patients. Prevention includes recognizing these anatomical structures at baseline cardiac imaging and intraprocedural precautions. Further studies are needed to analyze the actual incidence of this condition, its clinical impact and appropriate management.

Oral mexiletine for ventricular tachyarrhythmias treatment in implantable cardioverter-defibrillator patients: a systematic review of the literature.

INTRODUCTION: To evaluate the clinical outcomes of oral mexiletine (oMXT) to treat ventricular tachyarrhythmias (VTAs) in the era of implantable cardioverter-defibrillator (ICD) technology. EVIDENCE ACQUISITION: A systematic search was conducted using PubMed, Embase and Cochrane databases following the PRISMA guidelines to collect literature data reporting oMXT efficacy and safety outcomes in treating VTAs in ICD recipients. EVIDENCE SYNTHESIS: Final analysis included four studies accounting for a total of 91 patients with recurrent VTAs treated with oMXT. Amiodarone therapy was initially attempted in most patients (91.2%), while catheter ablation was performed in one-third of patients. VTA recurrences were observed in 55/91 patients (60.4%) during oMXT treatment compared to 91/91 (100%) before treatment (P<0.001). Appropriate therapies occurred in 55/88 ICD patients (62.5%) during oMXT treatment compared to 80/88 (90.9%) before treatment (P<0.001). After oMXT introduction, there was a significant reduction of the individual burden of VTA episodes and appropriate ICD therapies per patient, showing Hedges'g values of -1.103 (P=0.002) and -1.474 (P=0.008), respectively. Safety analysis showed a sample-weighted overall side-effect rate of 30%, while 21% of patients required drug reduction or discontinuation. Aggregated meta-regression analysis of the included studies and remote literature revealed a linear correlation between oMXT dosage and the overall side effects rate (r2 = 0.48; P=0.014). CONCLUSIONS: Oral mexiletine provides an adjunctive treatment to manage VTAs and reduces appropriate therapies in ICD patients with moderate efficacy and acceptable safety profiles. These observations await confirmation through randomised clinical trials.

The many NOs to the use of Class IC antiarrhythmics: weren't the guidelines too strict?

Class IC antiarrhythmic drugs (AADs) currently represent a cornerstone in the therapy of atrial fibrillation, both for the restoration of sinus rhythm and for the prophylaxis of long-term relapses. They also play an important role in the treatment of idiopathic ventricular arrhythmias. Following the results of the Cardiac Arrhythmia Suppression Trial study, flecainide and by extension the other Class IC AADs were contraindicated in patients with ischaemic and structural heart disease, due to their pro-arrhythmic effect and the consequent increase in mortality observed in the study. Recent studies carried out on patients with chronic coronary heart disease without previous heart attacks and/or residual ischaemia have shown a good safety profile for this class of drugs. In addition, other studies have shown excellent efficacy in the absence of pro-arrhythmic effects of Class IC AADs in patients with structural heart disease such as arrhythmogenic right ventricular cardiomyopathy (ARVC) and tachy-cardiomyopathy. The purpose of this review is to evaluate the appropriate use of Class IC AADs in the different patient subgroups, in the light of the evidence and new diagnostic and therapeutic tools available.

Air entrapment as a potential cause of early subcutaneous implantable cardioverter defibrillator malfunction: a systematic review of the literature.

AIMS: Air entrapment (AE) has been reported as a potential cause of early inappropriate shocks (ISs) following subcutaneous implantable cardioverter defibrillator (S-ICD) implantation, but a cause-effect relationship is not always evident. This systematic review aims to analyse this phenomenon concerning implantation techniques, electrogram (EGM) features, radiologic findings, and patient management. METHODS AND RESULTS: A systematic search was conducted using PubMed, Embase, and Google Scholar databases following the PRISMA guidelines to obtain all available literature data since 2010 on S-ICD malfunctions possibly due to AE. The final analysis included 54 patients with AE as a potential cause of S-ICD malfunction. Overall, the aggregate incidence of this condition was 1.2%. Of ICD malfunctions possibly due to AE, 93% were ISs, and 95% were recorded within the first week following implantation. Radiologic diagnosis of AE was confirmed in 28% of the entire study cohort and in 68% of patients in whom this diagnostic examination was reported. At the time of device malfunction, EGMs showed artefacts, baseline drift, and QRS voltage reduction in 95, 76, and 67% of episodes, respectively. Management included ICD reprogramming or testing, no action (observation), and invasive implant revision in 57, 33, and 10% of patients, respectively. No recurrences occurred during follow-up, irrespective of management performed. CONCLUSIONS: Device malfunction possibly due to AE may occur in ∼1% of S-ICD recipients. Diagnosis is strongly suggested by early occurrence, characteristic EGM features, and radiologic findings. Non-invasive management, principally device reprogramming, appears to be effective in most patients.

Electrocardiogram for the Diagnosis of Acute Myocardial Infarction in Patients with Right Ventricular Paced Rhythm: Old but Gold.

Ventricular pacing may interfere with the interpretation of ECG among patients with suspected acute myocardial infarction (AMI), with possible delay of reperfusion therapy. Since left bundle branch block has a similar ECG morphology to right ventricular paced rhythm, Sgarbossa and modified Sgarbossa criteria could be useful in this setting. We present four clinical cases in which a recently proposed clinical-instrumental algorithm has been adopted to manage patients with right ventricular paced rhythm and suspected AMI.

The revolution of the anti-diabetic drugs in cardiology.

Beginning in December 2008, under the auspices of Food and Drug Administration, numerous controlled clinical trial were planned, and in part completed, concerning the cardiovascular (CV) effects of hypoglycaemic drug in patients with Type 2 diabetes mellitus. At least 9 studies have been concluded, 13 are still open, and 4 have been initiated and closed ahead of time. Of the nine completed studies, three concerned inhibitor of the dipeptidyl peptidase 4 (inhibitors of DPP-4), four the glucagon-like peptide 1 agonist (GLP-1 agonist), and two the inhibitor of sodium-glucose co-transporter-2 (inhibitors of SGLT-2). Only four studies demonstrated the superiority, and not the mere 'non-inferiority', of the anti-diabetic drugs compared to placebo, in addition to standard treatment, in terms of reduction of the primary endpoint (CV death, non-fatal myocardial infarction, and non-fatal stroke). Two of the four studies regarded GLP-1 analogues (liraglutide and semaglutide), and two inhibitors of SGLT-2 (empaglifozin and canaglifozin). As a whole, these studies provided solid data supporting major beneficial CV effects of anti-diabetic drugs. During the next 3-4 years, an equal number of studies will be completed and published, so we will soon have the 'final word' on this issue. In the meantime, the clinical cardiologist should become familiar with these drugs, selecting the patients able to gain the best clinical advantage from this treatment, also by establishing a close relationship with the diabetologist.

Sudden Cardiac Death in Hypertensive Patients.

In patients with hypertension, but without established cardiovascular disease, predictive factors for sudden cardiac death (SCD) remain undefined. We followed for an average of 10.3 years a cohort of 3242 initially untreated hypertensive patients without evidence of coronary or cerebrovascular heart disease at entry. All patients underwent a complete clinical examination which included ECG and 24-hour ambulatory blood pressure monitoring. At entry, the mean age of patients was 50.0 years, 45% were women, and 6.1% had type 2 diabetes mellitus. Average office blood pressure was 154/96 mm Hg, and average 24-hour ambulatory blood pressure was 136/86 mm Hg. Prevalence of left ventricular hypertrophy at ECG was 13.9%. During follow-up, SCD occurred in 33 patients at a rate of 0.10 per 100 patient-years (95% CI, 0.07-0.14). The rate of SCD was 0.07 and 0.30 per 100 patient-years, respectively, in the cohort of patients without and with ECG left ventricular hypertrophy ( P<0.01). In a multivariable Cox model with Firth penalized maximum bias reduction method for rare outcome events, left ventricular hypertrophy almost tripled the risk of SCD (adjusted hazard ratio, 2.99; 95% CI, 1.47-6.09; P=0.002) after adjustment for age ( P<0.0001), sex ( P=0.019), diabetes mellitus ( P<0.0001), and 24-hour ambulatory pulse pressure ( P=0.036). For each 10 mm Hg increase in 24-hour ambulatory pulse pressure, the risk of SCD increased by 35%. The time-dependent area under the receiver operating characteristic curve was 0.85 (95% CI, 0.74-0.96). We conclude that in patients with hypertension without established cardiovascular disease, age, diabetes mellitus, ECG left ventricular hypertrophy, and 24-hour ambulatory pulse pressure are independent prognostic markers for SCD in the long-term.

Electrocardiography for diagnosis of left ventricular hypertrophy in hypertensive patients with atrial fibrillation.

Left ventricular (LV) hypertrophy at electrocardiography (ECG) predicts incident atrial fibrillation (AF). However, the diagnostic performance of ECG for diagnosis of LV hypertrophy in patients with AF is still not well characterized. We analyzed 563 hypertensive patients enrolled in the Umbria-Atrial Fibrillation (Umbria-FA) registry, an ongoing prospective observational registry in patients with AF. All patients underwent ECG and standard echocardiography at their entry in the Register. Mean age was 74 years and 43% of patients were women. Prevalence of ECG-LV hypertrophy, defined by Perugia criterion corrected for body mass index, was 23%. Echocardiographic LV mass was the reference standard. Sensitivity, specificity and diagnostic accuracy of ECG-LV hypertrophy were 37.4% (95% confidence interval [CI]: 31.6-43.4), 90.0% (95% CI: 86.0-93.2) and 64.5% (95% CI: 60.4-68.3), respectively. Performance was comparable in patients with AF or sinus rhythm at ECG recording. The area under the receiver-operating characteristic (ROC) curve was 0.622 (95% CI: 0.580-0.664) in the group with AF and 0.662 (95% CI: 0.605-0.720) in that with sinus rhythm (p â€‹= â€‹0.266 for comparison). These data suggest that standard ECG is reliable for diagnosis of LV hypertrophy in patients with a history of AF, regardless of the presence of AF or sinus rhythm at the time of ECG recording.

Long-term outcome in patients with non-valvular atrial fibrillation on dabigatran: a prospective cohort study.

INTRODUCTION: Most studies on thromboembolic and bleeding risk in patients with non-valvular atrial fibrillation (NVAF) exposed to non-vitamin K oral anticoagulants stem from interrogation of insurance databases. Areas covered: We studied 742 consecutive patients with NVAF who started treatment with dabigatran in three hospitals in Italy. Average follow-up was 1.80 years. Mean age was 76.2 years. CHA2DS2VASc score was 0-1 in 37 (5%), 2 in 97 (13%) and ≥ 3 in 604 (82%) patients. NVAF was permanent in 349 (48%). Overall, 76% of patients remained on treatment over the entire follow-up period. Among 180 patients who discontinued permanently, the most frequent reasons were dyspepsia (33.9%), bleeding (17.8%), and renal worsening (12.1%). About 48% and 74% of permanent discontinuations occurred during the first 6 and 12 months of treatment, respectively. Rates of major events (per 100 patient-years) were 0.75 for stroke, 0.31 for myocardial infarction, 1.50 for all-cause death, and 1.80 for major bleedings. The rate of intracranial bleedings was 0.45 and that of major gastrointestinal bleedings was 0.75. Expert opinion: This prospective cohort study confirms the low incidence of stroke, major bleeding and intracranial bleeding, and a 76% persistence with treatment, in patients with NVAF treated with dabigatran over about 2 years.

Impact of Chamber Dilatation on the Prognostic Value of Left Ventricular Geometry in Hypertension.

BACKGROUND: The different geometric patterns of the left ventricle may or may not coexist with chamber dilatation. The prognostic impact of such a combination is unclear. METHODS AND RESULTS: We studied a cohort of 2635 initially untreated patients with hypertension, mean age 50 years. At entry, 24-hour ambulatory blood pressure progressively increased across the patterns of normal geometry, concentric left ventricular (LV) remodeling, eccentric nondilated LV hypertrophy (LVH), eccentric dilated LVH, concentric nondilated LVH, and concentric dilated LVH. During a mean follow-up of 9.7 years, 360 patients developed a first major cardiovascular event at a rate (×100 patient-years) of 1.41. The event rate was 0.93 in the group with normal LV geometry, 1.10 in the group with LV concentric remodeling, 1.40 in the group with nondilated eccentric LVH, 2.10 in the group with eccentric dilated LVH, 2.34 in the group with nondilated concentric LVH, and 4.67 in the group with dilated concentric LVH (log-rank test: P<0.001). In a Cox model, after adjustment for several independent covariables (age, sex, diabetes mellitus, current smoking, total cholesterol, estimated glomerular filtration rate, and average 24-hour systolic blood pressure), concentric dilated LVH was associated with a 98% excess risk of cardiovascular events (P=0.0037). However, LV geometric pattern lost statistical significance when LV mass was entered into the model. CONCLUSIONS: In initially untreated patients with hypertension, LV dilatation adds an adverse prognostic burden to the patterns of eccentric and concentric LVH. This phenomenon is explained by the greater LV mass associated with LV chamber dilatation.