搜索结果：JACC. Clinical electrophysiology

Photoplethysmography (PPG) is a noninvasive optical technique for assessing cardiovascular physiology that has evolved into a widely used tool embedded in modern consumer wearables. By detecting changes in blood volume through light absorption, PPG provides both heart rate and rhythm information, as well as insights into broader physiological states. While electrocardiography (ECG) remains the gold standard for arrhythmia diagnosis, PPG offers a scalable and accessible alternative for continuous monitoring. Technically, PPG signals consist of a pulsatile component reflecting arterial blood flow and a baseline component from static tissues. These signals correlate closely with ECG-derived heart rate and can be used to derive additional metrics such as heart rate variability and vascular indices. Numerous studies have demonstrated the high accuracy of PPG for heart rate measurement, though performance can be affected by motion artifacts, skin tone, and reduced signal amplitude at high heart rates. PPG has shown strong performance in detecting atrial fibrillation, with high sensitivity and specificity in both algorithm-based and physician-interpreted analyses. However, ECG confirmation remains necessary for diagnosis given variability in study quality and limitations in distinguishing other arrhythmias. Clinically, PPG is valuable for atrial fibrillation screening, symptom-rhythm correlation, and remote monitoring, particularly in hybrid systems combining PPG with ECG. Future developments include expanded arrhythmia detection, machine learning integration, and contactless monitoring technologies. Despite its promise, widespread clinical adoption is currently limited by the lack of standardized technical frameworks and validation protocols. Overall, PPG represents a powerful adjunct to ECG, with significant potential to enhance patient-centered cardiovascular care.

Midmyocardial and subepicardial late gadolinium enhancement (LGE) are typical in inherited arrhythmogenic cardiomyopathy (ACM) and dilated cardiomyopathy (DCM). Transmural LGE, usually considered ischemic and excluded from ACM criteria, may also occur, but its clinical relevance is unclear. The objective of this study was to assess the prevalence, genetic associations, and prognostic significance of transmural LGE in patients with genotype-positive, nonischemic ACM/DCM. We retrospectively analyzed 1,379 genotype-positive patients with ACM/DCM, identifying 711 with cardiac magnetic resonance imaging and no significant coronary artery disease. Patients were stratified by LGE pattern (transmural, nontransmural, or absent). Major ventricular arrhythmic (MVA) and advanced heart failure (AHF) events were evaluated using Kaplan-Meier and age-adjusted Cox regression analyses. Transmural LGE was present in 5% (33/711) of patients and was enriched in LMNA and DSP variant carriers. Compared with nontransmural or absent LGE, transmural LGE was associated with higher rates of thromboembolic events, atrial fibrillation, and implantable cardioverter-defibrillator implantation (all P &#x2264; 0.003). It also conferred increased rates of MVA events (45% vs 27% vs 14%) and AHF therapies (18% vs 12% vs 6%) (P < 0.05). In age-adjusted models, transmural LGE independently predicted the composite endpoint of MVA/AHF compared with nontransmural LGE (HR: 1.9; P = 0.03) and no LGE (HR: 2.9; P = 0.0005). Transmural LGE identifies a small but high-risk subset of genotype-positive ACM/DCM, particularly among patients with LMNA and DSP variants, with significantly increased arrhythmic and heart failure risk.

Oral anticoagulation (OAC) and left atrial appendage closure (LAAC) are stroke prevention strategies for patients with atrial fibrillation. To compare stroke and bleeding outcomes from a meta-analysis of randomized controlled trials comparing LAAC to OAC. The primary outcome was stroke or systemic embolism (stroke/SE). Secondary outcomes included ischemic stroke, hemorrhagic stroke, major bleeding (MB), clinically significant bleeding (MB + clinically relevant nonmajor bleeding), non-procedure related clinically-significant bleeding, and cardiovascular or all-cause mortality. Seven randomized controlled trials met inclusion criteria (n = 7,353 patients; CHA2DS2-VASc score: 3.9; mean follow-up: 37.6 months), including 294 stroke/SE events. LAAC was similar to OAC for preventing stroke/SE (risk ratio [RR]: 1.10, 95% CI: 0.82-1.48). Clinically significant bleeding (RR: 0.60, 95% CI: 0.36-0.98) and non-procedure-related clinically significant bleeding (RR: 0.50, 95% CI: 0.39-0.64) were less frequent after LAAC. No statistically significant differences were observed for ischemic stroke, hemorrhagic stroke, MB, cardiovascular mortality, or all-cause mortality. The annualized incidence rate difference of stroke with LAAC did not increase with higher CHA2DS2-VASc scores and did not exceed 0.37%/year in any nonwarfarin-OAC comparative trial. In postablation patients, LAAC showed similar stroke/SE rates (RR: 0.92, 95% CI: 0.53-1.60; P-interaction = 0.76) and less nonprocedural clinically significant bleeding (RR: 0.51, 95% CI: 0.42-0.62; P-interaction = 0.56). LAAC prevents stroke/SE at rates not significantly different from OAC while reducing clinically significant bleeding, with possibly a more favorable benefit in postablation patients. In the full cohort, the numerically higher ischemic stroke rate was not statistically significant, and small in absolute terms. These findings support LAAC based on individualized, patient-centered decision-making, balancing stroke and bleeding risks.

Cardiac lymphoma can cause rapidly progressive high-grade atrioventricular block by infiltrating the conduction system. Because conduction disease may improve with lymphoma-directed therapy, pacemaker decisions are complex. A 44-year-old man with lymphoma developed extensive secondary cardiac involvement and progressive conduction system disease. Given the possibility of reversibility with immunotherapy, multidisciplinary discussions and shared decision-making were used to determine whether pacemaker implantation was warranted and to select the most appropriate device. An active-fixation leadless pacemaker was ultimately implanted. This case highlights the uncertainty regarding pacemaker management in cardiac lymphoma. Decisions should be individualized based on expected treatment response, infection risk, and patient preferences. Cardiac lymphoma may present with rapidly progressive conduction disease, and the degree of reversibility following lymphoma-directed therapy can be difficult to predict. Decisions regarding pacemaker implantation should be individualized and informed by the expected treatment response, infectious and procedural risks, and patient preferences.

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Bidirectional ventricular tachycardia is a rare electrocardiographic (ECG) finding, associated with a restricted group of clinical conditions, particularly hereditary channelopathies. An 11-year-old girl, asymptomatic from a cardiovascular point of view, was identified by family screening after detection in her father of a pathogenic variant in the KCNJ2 gene. The admission ECG showed bidirectional ventricular tachycardia. Clinical investigation revealed periodic paralysis and skeletal dysmorphisms, confirming a diagnosis of Andersen-Tawil syndrome. Pharmacological treatment significantly reduced the arrhythmic burden, with reverse ventricular remodeling at follow-up. This case illustrates the central role of ECG as a diagnostic tool in rare cardiovascular diseases, allowing early recognition, targeted genetic investigation, and prevention of arrhythmia-induced cardiomyopathy. Bidirectional ventricular tachycardia is a distinct ECG pattern that should raise suspicion of Andersen-Tawil syndrome and warrants genetic evaluation with cascade family screening. In this patient, the combination of propafenone and beta-blocker therapy was associated with suppression of bidirectional ventricular tachycardia, significant reduction in ventricular arrhythmic load, and reversal of tachycardiomyopathy, suggesting a potential therapeutic alternative when flecainide is not available.

Sick sinus syndrome (SSS) is caused primarily by sinoatrial node (SAN) dysfunction, often necessitating permanent pacemaker implantation. Although effective, electronic pacing has inherent limitations and hardware-related complications. Here, we developed a reproducible large-animal model of SSS to test the concept of "hardware-free" biological pacemaker therapy via percutaneous T-box transcription factor 18 (human) (TBX18) gene delivery. This study sought to create a preclinical model of SSS and rescue the phenoytpe by percutaneous delivery of TBX18 biological pacemaker. Healthy pigs underwent high-resolution electroanatomical mapping followed by targeted radiofrequency ablation of the SAN to induce sinus arrest. A backup electronic pacemaker was implanted to provide hemodynamic support. Two weeks postablation, after verification of SSS, the animals received percutaneous endovascular injection of either phosphate-buffered saline (n = 9) or TBX18 adenovirus (n = 9) into the lower atrial septum. Continuous electrocardiographic telemetry was performed for 4 weeks postinjection. By 2 weeks, TBX18-injected pigs exhibited higher intrinsic heart rates than controls (controls: 71.4 &#xb1; 4.0 beats/min vs TBX18: 96.3 &#xb1; 7.0 beats/min, P = 0.007) and reduced backup pacemaker use (P = 0.009). Heart rate variability analysis demonstrated improved rhythm stability in TBX18-injected animals (SD1/SD2, P = 0.0005), with fewer sinoatrial pauses and tachyarrhythmic episodes. Patch-clamp analysis of cells from the injection site revealed spontaneous action potentials and sinus node-like morphology, confirming the reprogramming of atrial myocytes into induced SAN-like cells. In this preclinical large-animal model of SSS, percutaneous TBX18 gene therapy successfully restored supraventricular pacemaker function, improved heart rate dynamics, and reduced reliance on electronic pacing. These findings support the use of biological pacemakers as a potential alternative to conventional device-based therapies for SSS.

The subcutaneous implantable cardioverter-defibrillator (S-ICD) is an established therapy for sudden cardiac death prevention, but sex-specific outcomes remain incompletely characterized. This study evaluated sex-related differences in baseline characteristics, appropriate shocks, complications, reinterventions, and mortality among S-ICD recipients. The nationwide HONEST (S-ICD French Cohort Study) cohort enrolled all patients who received an S-ICD in France between 2012 and 2019. Clinical endpoints were centrally adjudicated. Sex-specific associations with outcomes were assessed by using propensity score-based inverse probability weighting. Among 4,924 S-ICD recipients, 1,148 were women (23.3%). Compared with men, women were younger (47.3 &#xb1; 15.6 years vs 50.6 &#xb1; 14.7 years; P < 0.001), less frequently received an implant for primary prevention (57.6% vs 65.1%; P < 0.001), less often had coronary artery disease (38.9% vs 56.5%; P < 0.001), and more often had electrical heart disease (26.3% vs 20.4%; P < 0.001). After adjustment, women had a lower 5-year risk of appropriate shocks (HR: 0.85; 95% CI: 0.74-0.98; P = 0.023) and similar overall complication and reintervention rates but a distinct complication profile, with higher risks of chronic pain (HR: 2.63; 95% CI: 1.61-4.29; P < 0.001) and lead dislodgment (HR: 1.79; 95% CI: 1.09-2.95; P = 0.022) and a lower risk of inappropriate shocks (HR: 0.64; 95% CI: 0.50-0.82; P < 0.001). All-cause mortality was lower in women, whereas S-ICD-unresponsive sudden death and device-related mortality were similar. Women receiving an S-ICD experienced fewer appropriate shocks, with similar overall complication and reintervention rates, but a distinct complication profile. These findings support sex-informed S-ICD selection and follow-up. (S-ICD French Cohort Study [HONEST]; NCT05302115).

Short QT syndrome (SQTS) is a rare inherited channelopathy associated with malignant ventricular arrhythmias and sudden cardiac death. A 48-year-old man presented with syncope without prodromes. Electrocardiogram showed a QTc of 320 ms and family history included sudden death at 16 years. Cardiac evaluation was unremarkable, while tilt testing suggested vasovagal syncope. Genetic testing identified a synonymous RYR2 variant of uncertain significance. Despite a probable SQTS diagnosis, the absence of ventricular arrhythmias supported an intermediate-risk profile. An implantable loop recorder was implanted. At 12 months, no arrhythmic events were detected. SQTS risk stratification remains challenging, particularly in the absence of pathogenic variants. This case suggests that noncanonical genetic findings may expand the genetic spectrum of SQTS, while requiring cautious interpretation. Risk stratification in SQTS should integrate clinical context. In selected intermediate-risk patients, conservative management with longitudinal monitoring may be appropriate.

Wide-complex tachycardia poses diagnostic and therapeutic challenges, particularly when class IC antiarrhythmic toxicity mimics ventricular tachycardia (VT). An 85-year-old woman with a dual-chamber pacemaker, paroxysmal atrial fibrillation on flecainide, and chronic kidney disease presented with dyspnea and a wide-complex tachycardia initially diagnosed as VT. Intravenous amiodarone was administered. Initial device interrogation revealed ventricular sensing at 496 ms cycle length without atrial tracking. Ventricular overdrive pacing demonstrated that the atrial cycle length did not accelerate to the pacing rate, confirming an independent atrial tachycardia at 551 ms and excluding atrioventricular reentrant tachycardia and VT with retrograde conduction. The Ventricular Intrinsic Preference algorithm subsequently demonstrated intact atrioventricular conduction, proving the wide QRS was aberrancy. Recognition of potential amiodarone-flecainide interaction prompted drug cessation and sodium bicarbonate therapy, leading to clinical recovery. This case demonstrates how pacemaker diagnostics can differentiate flecainide-induced aberrancy from VT and highlights the important drug-drug interaction between amiodarone and flecainide via CYP450 inhibition. In patients with pacemakers presenting with wide-complex tachycardia, device interrogation and knowledge of programmed parameters are helpful to differentiate supraventricular tachycardia with aberrancy from VT.

Stereotactic arrhythmia radioablation (STAR) has been proposed to treat refractory ventricular tachycardia (VT) in patients with structural heart disease (SHD). The aim of the STAR-VT-2020 (Stereotactic Ablative Radiosurgery of Recurrent Ventricular Tachycardia in Structural Heart Disease) randomized trial was to compare the efficacy of STAR and catheter ablation (CA) after a failure of previous CA. Patients with VT recurrences were randomized at 2 centers (June 2020 to January 2024) to the STAR or CA group in a 1:1 fashion using a covariate-adaptive algorithm. In the STAR group, the arrhythmogenic substrate was irradiated by a single dose of 25 Gy delivered by a robotic system (CyberKnife). The planning target volume was delineated by coregistering the electroanatomical substrate map (CARTO 3) with the planning computed tomographic scan. In the CA group, CA was performed using substrate modification strategies. The primary endpoint was VT recurrence, while repeated CA was one of the secondary endpoints. A total of 22 patients (68% men, mean age 67 &#xb1; 11 years, 27% with ischemic cardiomyopathy, mean left ventricular ejection fraction 31% &#xb1; 9%, 3.0 &#xb1; 1.3 previous CAs) were enrolled (11 in each group) and followed for 28 &#xb1; 17 months. The STAR patients exhibited a nonsignificantly higher risk for VT recurrence (HR: 2.5; 95% CI: 0.97-6.6) than those who underwent CA, and a significantly higher risk of repeated CA for VT (HR: 4.0; 95% CI: 1.2-13.8). Throughout the trial, 13 patients died, 3 underwent heart transplantation, and 3 received left ventricular assist devices, with no significant differences between the 2 groups. The STAR-VT-2020 trial suggests a potential clinical benefit of repeated CA over STAR in patients with SHD, despite prior failed CA at specialized centers. Because of the small study cohort of highly selected patients and several methodological limitations, the results of the prematurely terminated trial should be considered exploratory and interpreted strictly as hypothesis generating. Larger trials with optimized design are warranted. (Stereotactic Ablative Radiosurgery of Recurrent Ventricular Tachycardia in Structural Heart Disease; NCT04612140).

Sudden cardiac death (SCD) caused by ventricular arrhythmias remains a leading cause of mortality worldwide. Current risk stratification for implantable-cardioverter defibrillator (ICD) insertion relies heavily on left ventricular ejection fraction, which has limited discriminatory power. The goal of this study was to evaluate whether established/novel magnetocardiography (MCG) parameters (Rotation Score and Angular Dynamics) were associated with subsequent ICD therapies. Magneto-SCD (Magnetocardiography [MCG] Parameters in the Prediction of Future ICD Therapy) was a prospective, multicenter observational study of de novo ICD recipients across 5 UK hospitals between September 2019 and November 2021. MCG data were obtained by using a portable, unshielded, room temperature device. The primary outcome was occurrence of any appropriate ICD therapy. Secondary outcomes included any appropriate shocks, sustained ventricular arrhythmias, and all-cause mortality. A total of 104 patients were recruited (mean age &#xb1; SD 65.5 &#xb1; 12.2 years; 80% male); 90 had analyzable MCG data. After mean follow-up of 36.0 &#xb1; 17.5 months, 17 received appropriate ICD therapy, with a significantly higher median (Q1-Q3) Rotation Score (504.4 [398.5-665.3] vs 331.7 [256.6-472.2]; P = 0.005) and Angular Dynamics (3.26 [2.55-3.81] vs 2.50 [2.12-3.13]; P = 0.029). These differences in Rotation Score/Angular Dynamics were more marked in those with appropriate shocks (539.7 [428.5-674.5] vs 335.1 [256.3-476.6]; P = 0.001 and 3.348 [2.879-3.830] vs 2.492 [2.117-3.132]; P = 0.005, respectively). Each 1-SD increase in Rotation Score/Angular Dynamics was associated with a higher hazard of appropriate shocks (2.53 [95% CI: 1.53-4.18] and 2.34 [95% CI: 1.37-4.00]) and appropriate therapy. Rotation Score/Angular Dynamics showed apparent discrimination for shocks in this small data set (receiver-operating characteristic area under the curve: 0.82 and 0.77), although CIs were wide and event numbers were small. Associations persisted after limited adjustment for age and left ventricular ejection fraction, supporting an association independent of age and left ventricular ejection fraction within an ICD-selected cohort, although this requires independent validation. In the current study, novel rotation-based MCG parameters were associated with subsequent appropriate ICD therapies, particularly shocks. These exploratory findings support the feasibility of unshielded MCG in routine clinical practice and suggest that Rotation Score/Angular Dynamics may capture arrhythmic substrate and merit further investigation and validation in larger cohorts. (Magnetocardiography [MCG] Parameters in the Prediction of Future ICD Therapy [Magneto-SCD]; NCT04352816; EudraCT2019-002994-78).

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In patients with interrupted inferior vena cava (IVC) requiring atrial fibrillation (AF) ablation, transhepatic access is an established alternative to femoral venous access. Prior reports have described AF ablation using radiofrequency platforms, but, to our knowledge, transhepatic AF ablation with a dual-energy lattice-tip catheter integrating high-density mapping, pulsed field ablation, and radiofrequency ablation has not been reported. We describe 3 patients with symptomatic AF and interrupted IVC who underwent successful transhepatic left atrial access using ultrasound-guided placement of a 12-F hemostatic sheath. Pulmonary vein isolation and posterior wall isolation were performed with pulsed field ablation in all patients. Hepatic tract closure was achieved using absorbable gauze within the hepatic parenchyma. No access-related or procedural complications occurred, and all patients recovered uneventfully. This series demonstrates the feasibility of transhepatic AF ablation using a dual-energy lattice-tip catheter. Further studies are needed to define procedural safety and long-term outcomes.

Patients undergoing repeat procedures for atrial fibrillation (AF) recurrence may have undergone an index procedure with pulsed field ablation (PFA) or radiofrequency ablation (RFA). Whether differences exist in the anatomical distribution and extent of pulmonary vein (PV) reconnection has not been described. This study sought to compare the distribution and extent of PV reconnection in patients undergoing redo AF ablation after index PFA vs RFA rather than the durability of pulmonary vein isolation (PVI) between ablation technologies. In this retrospective multicenter observational study, consecutive patients undergoing high-density multipolar mapping and RFA for recurrent AF with PV reconnection following index RFA or PFA were enrolled between March 2024 and October 2025. A total of 103 patients (mean age 65 &#xb1; 10 years, paroxysmal AF in 67%, 34% female) underwent redo ablation following index PVI, with RFA in 53 and PFA in 50. The number of PVs reconnected was higher post-index PFA than RFA (2.7 &#xb1; 1 vs 2.0 &#xb1; 0.8 RFA; P < 0.001). Reconnection of the left PVs was more frequent post-PFA (86% vs 49% RFA; P < 0.01), with no difference for right PVs (74% vs 75% RFA; P = 1.0). The extent of PV reconnection was greater post-PFA (87 mm [Q1-Q3: 56-121 mm] vs 19 mm [Q1-Q3: 12-38 mm] post-RFA; P < 0.001). PV reconnection was more common anteriorly post-PFA vs posterior and carinal post-RFA. In patients undergoing repeat ablation for recurrent AF, reconnection more commonly involved the left PVs, was more extensive, and required significantly more ablation following index pentaspline PFA compared with index point-by-point RFA. No direct comparison of PVI durability can be made between PFA and RFA based on these results.

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