Circulation. Arrhythmia and electrophysiology最新文献

Background: Multiple extrastimulus (ES) pacing protocols exist for ventricular substrate mapping. Despite being increasingly adopted in clinical practice, direct protocol comparisons have been limited. This study aims to compare the substrate delineation and mapping efficiency of right ventricular pacing+ES (RVp+ES) and sensed ES pacing strategies in a large animal ischemia-reperfusion injury model.

Methods: Four swine underwent 90-minute balloon occlusion of the mid-left anterior descending artery, followed by late gadolinium-enhanced cardiac magnetic resonance between days 30 and 58 and invasive electroanatomic mapping. Late gadolinium-enhanced cardiac magnetic resonances were segmented for scar topography and border zone channel geometry.

Results: Sensed ES substrate maps had greater point density (12.90±4.20 pts/cm² versus 5.75±0.52 pts/cm²; P=0.032) and faster acquisition (113.71±22.38 s/pt per cm² versus 228.57±77.30 s/pt per cm²; P=0.027) than RVp+ES. Despite this, RVp+ES substrate maps had greater uncovering of split potentials within border zone channels (76.5% [15.4%-95.5%] versus 16.7% [0%-52.9%]; P=0.028), higher sensitivity (53% versus 30%), and similarly high specificity (91% versus 93%) than sensed ES, as well as better visual correlation on decrement-evoked potential maps. Bipolar voltage in sinus rhythm and RVp did not reliably predict tissue response to ES, with 46% to 57% of split potentials within border zone channels arising from seemingly normal voltage (≥1.5 mV).

Conclusions: RVp+ES is more sensitive than sensed ES and highly specific for the detection of late gadolinium-enhanced cardiac magnetic resonance border zone channels postmyocardial infarct.

Background: In the randomized controlled SUPPRESS-AF trial (Efficacy and Safety of Left Atrial Low-voltage Area Guided Ablation for Recurrence Prevention Compared to Pulmonary Vein Isolation Alone in Patients with Persistent Atrial Fibrillation), the efficacy of low-voltage-area (LVA) ablation was highly dependent on the degree of atrial remodeling, while the efficacy was not statistically significant in total patients. This subanalysis of the SUPPRESS-AF trial aimed to compare the efficacy of LVA ablation in patient groups classified by left atrial diameter (LAD), which is a commonly used atrial remodeling index.

Methods: The SUPPRESS-AF trial included patients with persistent AF and left atrial LVAs, and compared rhythm outcomes between patients randomized to undergo pulmonary vein isolation (PVI) followed by left atrial LVA ablation group (n=170) or PVI-alone group (n=172). In this post hoc subanalysis, patients in each of the 2 randomly allocated groups were further divided into 2 groups using a median LAD of 44 mm.

Results: Atrial fibrillation or atrial tachycardia recurrence-free rates did not differ between patients with LAD>44 mm and ≤44 mm (60.1% versus 53.7%; P=0.261). Among patients with a LAD>44 mm, the LVA ablation group demonstrated a higher atrial fibrillation or atrial tachycardia-recurrence-free rate than the PVI-alone group (62.5% versus 43.4%; P=0.016). In contrast, no difference in atrial fibrillation or atrial tachycardia recurrence-free rate was found between the 2 groups of patients with a LAD≤44 mm (60.8% versus 59.6%; P=0.986).

Conclusions: The efficacy of LVA ablation in addition to PVI for the treatment of persistent AF was more pronounced in patients with a large left atrium.

Registration: URL: https://www.umin.ac.jp/ctr; Unique identifier: UMIN000035940.

Background: Hyperactivity of sympathetic neurons in the stellate ganglia (SG) contributes to ventricular arrhythmias and remodeling postmyocardial infarction (MI). However, the role of satellite glial cells (SGCs) surrounding the neurons in this process remains unknown.

Methods: SGC-specific chemogenetic manipulation was locally applied to modulate SG-SGC activity dual-directionally in the rats with naïve or infarcted hearts. Subsequently, cardiac sympathetic neural activity and ventricular electrophysiological stability in response to stimulation were evaluated, as well as cardiac neural and structural remodeling post-MI. SG bulk RNA sequencing and the interaction between SGCs and sympathetic neurons isolated from SG were used to explore the underpinning mechanisms.

Results: SG-SGC excitation increased SG neural activity and ventricular electrophysiological instability in rats with naïve hearts, whereas its inhibition influenced none of the above under physiological conditions. Of note, 2-hour-MI provoked SG-SGC activation that positively correlated with cardiac sympathetic neurotransmitter (norepinephrine) release. Accordingly, SGC activation in the SG enhanced cardiac sympathetic hyperactivity 2 hours post-MI, whereas SG-SGC inhibition suppressed MI-induced cardiac sympathetic hyperexcitability. Moreover, the persistent inhibition of SG-SGCs improved ventricular remodeling and dysfunction, alleviated SG and ventricular sympathetic nerve sprouting 7 days post-MI. In addition, the bulk RNA sequencing with SG and pharmacological purinergic P2Y1R (P2Y1 receptor) blockage indicated that P2Y1R/IGFBP2 (insulin-like growth factor-binding protein 2) signaling mediated the effects of SG-SGC activation on cardiac sympathetic hyperexcitability post-MI, and IGFBP2 bridged the interaction between the neurons and surrounding SGCs.

Conclusions: SGC inhibition in SG rectifies cardiac sympathetic hyperactivity, stabilizes ventricular electrophysiological properties, and alleviates cardiac structural and neural remodeling post-MI, thereby preventing ventricular arrhythmias and cardiac dysfunction. Neuromodulation targeting SG-SGCs exhibits a safe and fruitful strategy for the treatment of MI.

Background: The incidence of postural orthostatic tachycardia syndrome (POTS) in long COVID has been a growing concern since the first cases were reported in 2021. The aim of this study was to assess the prevalence and clinical impact of POTS in a series of well-characterized patients with long COVID.

Methods: We prospectively analyzed 467 nonhospitalized, highly symptomatic (sick leave ≥50%) patients with long COVID, and studied differences in demographics and clinical assessment outcomes between those diagnosed with POTS and the remaining long COVID patients. Examinations were performed at a median of 12 months after acute COVID-19, followed by a cardiologist evaluation with 48-hour ECG, head-up tilt test, and Active Stand Test for those with clinically suspected POTS.

Results: Of all long COVID patients, 143 (31%) were diagnosed with POTS, 128 (27%) did not fulfill POTS criteria, while 196 (42%) had no clinical signs of POTS. Patients with POTS were younger (mean age, 40.0 versus 44.0 versus 47.0 years, respectively; P≤0.001) and predominantly female (91%). They had significantly lower physical activity compared with the other 2 groups, as measured with the Frändin-Grimby scale (P=0.001). Heart rates during the 6-minute walk test were significantly higher in the POTS group, both during walking and at rest afterward, with a significantly shorter walking distance (448 m versus 472 m versus 509 m, respectively; P≤0.001). However, the distribution of symptoms showed no significant differences between the groups.

Conclusions: In this cohort of predominantly younger women with highly symptomatic long COVID, POTS is common and presents with overlapping symptoms between POTS and non-POTS patients. Long COVID POTS confers lower physical activity and capacity compared with non-POTS long COVID and should be systematically assessed in this condition.

Background: We aimed to refine and validate a deep neural network model from the ECG to predict atrial fibrillation (AF) risk, using samples from diverse backgrounds: the Framingham Heart Study (FHS), UK Biobank, and Estudo Longitudinal da Saúde do Adulto (ELSA-Brasil). We compared the model's performance to the clinical Cohorts for Heart and Aging Research in Genomic Epidemiology consortium (CHARGE-AF) risk score and evaluated the association with other cardiovascular outcomes.

Methods: The ECG-derived deep-learning prediction of AF (ECG-AF) model was refined using 60% of FHS samples free of AF. Its performance was then tested in the remaining FHS samples, UK Biobank, and ELSA-Brasil, with discrimination assessed by the area under the receiver operating characteristic curve. The association of ECG-AF with cardiovascular outcomes was assessed using Cox proportional hazards models.

Results: The study sample included 10 097 FHS participants (mean age 53±12 years; 54.9% women), 49 280 participants from the UK Biobank (mean age 64±8 years, 47.9% women), and 12 284 participants from ELSA-Brasil (mean age 53±8 years, 54.7% women). The ECG-AF model showed moderate discrimination for incident AF (area under the curve, 0.82 [95% CI, 0.80-0.84]) in the FHS, comparable to the CHARGE-AF score (area under the curve, 0.83 [95% CI, 0.81-0.85]), and incremental when combined (area under the curve, 0.85 [95% CI, 0.83-0.87]). In UK Biobank and ELSA-Brasil, combining ECG-AF and CHARGE also improved prediction. Higher ECG-AF scores were associated with increased risks of heart failure, myocardial infarction, stroke, and all-cause mortality in all 3 cohorts.

Conclusions: In multinational cohort studies, the single-input ECG-AF deep neural network model demonstrated good performance in predicting AF and other cardiovascular outcomes, comparable to a multivariable clinical risk score, with improved performance when combined.