Circulation. Arrhythmia and electrophysiology最新文献

Background: Marked intellectual and neurodevelopmental delay (INDD) was noted in 6 unrelated patients diagnosed with RYR2-related catecholaminergic polymorphic ventricular tachycardia (CPVT) from a single center. Patients exhibited similar distinct phenotypic features not previously described. We aimed to determine the prevalence of INDD in CPVT, compare clinical characteristics between patients with CPVT with and without INDD, and investigate the possibility of a unique neurocardiac CPVT phenotype.

Methods: Retrospective combined review of patients with RYR2-related CPVT diagnosed ≤18 years with and without INDD from a single center and the International Pediatric CPVT Registry. Patients with hypoxic ischemic insult were excluded unless INDD preceded injury.

Results: Among a total of 168 patients, INDD was reported in 19 (11.3% [95% CI, 7.0%-17.1%]). When compared with cases without INDD, patients with INDD exhibited distinct features including (1) younger age at onset of symptoms (median 7.0 versus 10.0 years; P=0.04); (2) higher frequency of atrial tachyarrhythmias (84.2% versus 16.3%, P<0.001); (3) atrial or ventricular tachycardia without adrenergic stimulation (81.3% versus 2.2%, P<0.001, 31.6% versus 4.5%, P=0.001 respectively); (4) cardiac structural changes or systolic dysfunction (36.8% versus 1.3%, P<0.001); and (5) higher incidence of cardiac arrest or sudden death after diagnosis (26.3% versus 2.7%, P=0.001). INDD-related RYR2 genetic variants clustered within the central and channel domains and may be specific to certain variants.

Conclusions: This study demonstrates a wider spectrum of RYR2-related disease, with a subset associated with extracardiac manifestations. Certain RYR2 variants may lead to a neurocardiac phenotype with distinct features that are important to recognize, as these patients may be at higher risk.

Background: Various pulsed field ablation (PFA) parameters have been proposed to improve lesion depth. This study evaluated a modified unipolar return PFA system to create deep lesions in healthy and infarcted ventricular myocardia.

Methods: Numerical modeling was used to compare a modified unipolar return PFA system configuration with a conventional unipolar return (skin patch). We then performed ablation in 14 swine (5 with chronic myocardial infarction and 9 healthy). PFA lesions were created in the left ventricle using a focal catheter (4-mm tip) with a return electrode positioned in the inferior vena cava (biphasic, microsecond pulses of 1300 and 1500 V, 1-16 trains). Electroanatomical mapping guided ablation and lesion localization on magnetic resonance imaging were performed 48 hours post-ablation in the infarcted group and at 1 day, 7 days, and 6 weeks post-ablation in the healthy group.

Results: Numerical modeling demonstrated that the modified unipolar return PFA system produced deeper lesions with reduced variability compared with the skin patch. In healthy pigs (n=35 lesions), depths of 6.8±1.8 mm and widths of 11.5±4.7 mm were achieved with 8 pulse trains. Depths of 8.2±2.8 mm and widths of 14.0±4.7 mm were achieved with 16 trains. The maximum lesion depths were 8.8 and 11.6 mm for 8 and 16 trains, respectively. In the infarcted cohort (n=22 lesions), all lesions applied to scar tissue penetrated through fibrotic regions, with epicardial involvement observed in 57% of lesions.

Conclusions: The modified unipolar return PFA system effectively creates large lesions and can achieve transmurality in healthy and infarcted animals. Compared with conventional unipolar, it may offer greater lesion depth, width, and consistency.

Background: The safety and efficacy of pulsed field ablation for pulmonary vein and posterior wall isolation in atrial fibrillation ablation are well established; however, evidence regarding its use in extra-pulmonary vein areas remains limited. The aim of this study was to assess the feasibility and durability of pulsed field ablation for coronary sinus (CS) and left atrial appendage (LAA) isolation and mitral isthmus (MI) ablation.

Methods: We analyzed data from consecutive patients who underwent repeat atrial fibrillation ablation with pulsed field ablation between February and October 2024. MI ablation, CS isolation, and LAA isolation were attempted in all patients using the Farapulse (Boston Scientific) ablation system. Acute isolation was assessed after a 20-minute waiting period and an adenosine challenge, while chronic durability was evaluated during a repeat procedure for LAA closure at 3 months.

Results: A total of 236 patients (145, 61.4% men) were included in our analysis. Acute CS isolation was achieved in 147 (62.2%) patients for the CS and in all patients for the LAA. Acute MI block was obtained in all patients. After a 20-minute waiting time, the adenosine challenge revealed dormant conduction in 52 (26.4%) cases for the CS, in 4 (1.7%) for the LAA, and MI block regression in 35 (14.8%). All patients underwent remapping at the time of left atrial appendage occlusion, which showed CS and LAA isolation in only 3 (1.3%) and 10 (4.6%) patients, respectively, and MI block in 13 (5.5%) cases.

Conclusions: Pulsed field ablation is a feasible and acutely effective method for CS and LAA isolation and MI block; however, lesion durability remains a significant limitation.

Background: Fetal tachycardias can cause adverse fetal outcomes including ventricular dysfunction, hydrops, and fetal demise. Postnatally, ECG is the gold standard, but, in fetal practice, echocardiography is used most frequently to diagnose and monitor fetal arrhythmias. Noninvasive extraction of the fetal ECG (fECG) may provide additional information about the electrophysiological mechanism and monitoring of intermittent arrhythmias. Signal processing advances could provide improved data quality impacting clinical translation. The aim of this study was to assess the fetus with known or suspected tachycardia using noninvasive abdominal fECG and correlate results with fetal echocardiography and postnatal ECG.

Methods: Prospective recruitment of pregnant participants with known or suspected fetal tachycardia in a tertiary fetal cardiology unit. Overnight fECG recording at home using the MonicaAN24 monitor was performed. Data processing using bespoke MATLAB scripts was undertaken to produce fetal heart rate and beat-to-beat rhythm strips. Comparison of fECG data with clinical data obtained using echocardiography and postnatal findings. Data are presented as median (interquartile range; range).

Results: Fifteen participants undertook 1 to 4 fECG recordings, giving a total of 23 recordings. Gestational age was 28.9 (23.9-34.3; 21-39.1) weeks. Duration of recording was 512 (380-609; 5-1259) minutes. Intermittent tachycardia was demonstrated on fetal heart rate graphs. Rhythm strips correctly identified short-ventriculoatrial and long-ventriculoatrial tachycardia, atrial flutter, and sinus rhythm with findings correlating with echocardiography. Postnatal ECG correlation was possible in 3.

Conclusions: We have shown that rhythm strips of fECG signals can be extracted and correctly identify the electrical mechanism of arrhythmia in cases of fetal tachycardia. The potential to monitor fetal heart rate over a prolonged period is an advantage over current monitoring strategies for documentation of intermittent arrhythmias and gauging the response to medical therapy. These data will enable research to focus on improvement in signal quality, assessment of other arrhythmia subtypes, and real-time ambulatory monitoring of the fetal rhythm.

Background: Identification of fast ventricular tachycardia (FVT; cycle length <320 ms) isthmuses is often hindered by hemodynamic instability during sustained FVT and by rate-dependent (functional) scar properties. Comparing ultra-high-density voltage heterogeneity maps (0.1-1.5 mV) of the scar area during sinus rhythm (SR) and FVT may delineate the rate-dependent components of the FVT isthmus (FVTI) and improve substrate identification during SR.

Methods: Thirty Large White swine with anterior myocardial infarction underwent cardiac magnetic resonance imaging for signal intensity mapping, followed by electrophysiological studies at 4 and 16 weeks post-infarction. FVTIs were defined as corridors of high-frequency electrograms spanning electric diastole and completing reentrant circuits in activation maps. Voltage heterogeneity mapping during FVT and SR was performed to identify voltage channels and delineate functional substrate. Statistical comparisons were performed using the Student t test, with data presented as mean±SD.

Results: Sixty ventricular tachycardias were induced, including 27 monomorphic episodes with a cycle length < 320 ms. Of these, 25 exhibited reentrant activation with identifiable FVTI. All FVTIs were housed within channels identified in voltage heterogeneity maps during FVT and signal intensity maps; 22 of 25 (88%) colocalized with a channel visible in SR voltage maps. Comparing FVT and SR voltage maps revealed that (1) dense scar area (<0.1 mV) was larger in FVT than in SR maps (1.5±0.3 versus 0.1±0.2 cm², P<0.001), (2) voltage channels sustaining FVTI in FVT were longer than in SR (18.7±7.1 versus 14.6±6.1 mm, P=0.047), and (3) while all channels in FVT maps were bordered by dense scar (<0.1 mV), only 4 in SR exhibited this feature, indicating a functional substrate in 84% of FVTIs.

Conclusions: FVTIs are located within channels identified in voltage heterogeneity maps during SR and FVT. These channels colocalize with heterogeneous tissue channels in signal intensity maps. Comparative analysis of SR and FVT voltage maps enables delineation of functional borders.

Background: Atrial tachyarrhythmia recurrence remains the primary end point of clinical trials evaluating therapeutic pharmacological and nonpharmacological interventions for atrial fibrillation (AF). We sought to examine the relationship between the timing of first atrial tachyarrhythmia recurrence and subsequent AF burden.

Methods: We performed a patient-level analysis of 2 multicenter prospective parallel-group, single-blinded randomized clinical trials that used continuous rhythm monitoring after rhythm intervention. Patients with paroxysmal AF were stratified based on the month where the first recurrence of atrial tachyarrhythmia was observed, after a 2-month blanking period. AF burden was calculated as the time spent in AF at 1 year after first recurrence and over 3 years of follow-up.

Results: A total of 51.7% of patients experienced a recurrence of atrial tachyarrhythmia in the first year of follow-up. A first recurrence of atrial tachyarrhythmia occurred in 56.5% of patients within the third month post treatment initiation, with 79.5% of all recurrences detected by month 6 and 90.2% detected by month 9. The median postrecurrence AF burden was significantly greater in those with first recurrence in month 3 (1.04% [interquartile range, 0.23-5.05]) when compared with those patients with first recurrence between months 4 to 12 (0.13% [interquartile range, 0.04-0.63]; P<0.0001 versus month 3) and those with first recurrence after month 12 (0.05% [interquartile range, 0.01-0.20]; P<0.0001 versus month 3).

Conclusions: Atrial tachyarrhythmia recurrence after rhythm control intervention for paroxysmal AF is not uniform, with earlier recurrences being associated with higher AF burden on follow-up. These findings suggest that the timing of arrhythmia recurrence is of critical importance, with later recurrences being of progressively lesser clinical significance.

Background: Bradyarrhythmia is a common and potentially serious cause of syncope, often difficult to detect due to its intermittent nature. Traditional ECG monitoring methods either provide low diagnostic accuracy or delay diagnosis, increasing the risk of recurrence. We hypothesized that a deep learning-enabled, 24-hour, single-lead ECG could detect past episodes of bradyarrhythmia.

Methods: Using unselected 14-day single-lead ambulatory ECG recordings, we developed a deep learning model to identify patients with prior asystole from sinus arrest or complete heart block. The model was trained using the last 24 hours of each recording, free of bradyarrhythmias, to identify daytime sinus pause of ≥3 s, anytime sinus pause of ≥6 s, complete heart block, or a composite of these bradyarrhythmias from the previous 13 days.

Results: A total of 320 959 unselected 14-day ambulatory ECG recordings (mean age, 60.5±17.8 years; 60% female) were split into training (n=189 414), tuning (n=45 982), internal validation (n=43 390), and external validation (n=42 173) sets. External validation of prior daytime sinus pause ≥3 s, anytime sinus pause ≥6 s, complete heart block, and a composite end point demonstrated an area under the receiver operating characteristic curve of 0.89, 0.87, 0.93, and 0.89, respectively, with negative predictive values between 97.9 and 99.9%. In addition to this approach of uncovering past events, our model was also tested for its ability to predict bradyarrhythmias within the following 13 days using the first 24 hours of ECG data, achieving an AUC of 0.88 for the composite end point.

Conclusions: A deep learning-enabled ambulatory ECG is capable of unmasking underlying conduction tissue system disease. This tool may help identify patients with significant intermittent bradyarrhythmia, potentially improving timely diagnosis and management.