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The pathogenesis of chronic active myocarditis remains unclear. A 65-year-old man underwent permanent pacemaker implantation for sick sinus syndrome and pulmonary vein isolation for paroxysmal atrial fibrillation. Four years later, the left ventricular ejection fraction decreased from 51â¯% to 35â¯%, and the apical left ventricular inferior wall developed akinesis. Isolated cardiac sarcoidosis was suspected; however, prednisolone and optimal medical therapy failed to improve the symptoms. Even after cardiac resynchronization therapy followed by atrioventricular junction ablation for untreatable atrial tachycardia, the patient died of heart failure eight years after referral. An autopsy revealed inflammatory cell infiltration accompanied by cardiac myocytolysis in both atria and ventricles. He was diagnosed with chronic active myocarditis based on pathological findings and a persistent increase in the blood high-sensitivity cardiac troponin levels before death. The myocardium around the sinus node showed extensive and severe fibrosis with mild inflammation, suggesting a chronic inflammatory phase. In contrast, the left atrium and both ventricles showed active myocardial inflammation with fibrosis, suggesting a persistently active inflammatory phase. This case demonstrated that atrial inflammation caused intractable atrial arrhythmia, while ventricular inflammation led to biventricular heart failure, and highlighted the presence of spatially and temporally heterogeneous inflammation in chronic active myocarditis. Learning objective: We describe a case of chronic active myocarditis with spatially and temporally heterogeneous lesions throughout the four cardiac chambers. Inflammatory cell infiltration was observed in both atria and ventricles. Extensive fibrosis replaced the myocardium around the sinus node, suggesting a chronic phase. The left atrium and ventricles showed active inflammation, suggesting an active phase. Atrial and ventricular inflammation led to atrial arrhythmia and heart failure, respectively.
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Objectives: This study aimed to summarize the existing literature on risk factors for arrhythmias after chemotherapy in cancer patients. To provide reliable evidence for treating arrhythmias after chemotherapy in oncology patients by assessing multiple biasing factors in the literature and quantifying the risk factors. Methods: The risk factors for arrhythmia following tumor chemotherapy were systematically collected from various reputable databases, including PubMed, Cochrane Library, MEDLINE, EMBASE, and multiple Chinese databases, covering the period from inception to May 2023. Two independent reviewers performed rigorous article screening, data extraction, and assessment of research quality. Data analysis was conducted using Review Manager 5.4 software, ensuring a standardized and robust approach to evaluate the gathered evidence. Results: The analysis of chemotherapy-induced arrhythmias included 16 articles, encompassing 14,785 cancer patients. Among the patients, 3295 belonged to the arrhythmia group, while 11,490 were in the non-arrhythmia group. These studies identified 12 significant risk factors associated with arrhythmias following chemotherapy in cancer patients. The findings of the analysis are as follows. General patient characteristics: The incidence of post-chemotherapy arrhythmias was 14.33 times higher in oncology patients aged ≥60 years compared to patients <60 years of age [OR = 14.33, 95%CI (8.51, 24.13), Pï¼0.00001]. Patients with a smoking history exhibited a 1.67-fold higher risk of arrhythmia after chemotherapy [OR = 1.67, 95%CI (1.24, 2.25), P = 0.0007]. However, there was no significant correlation between gender and body mass index (BMI) with arrhythmia after chemotherapy in oncology patients (P = 0.52; P = 0.19). Disease-related factors: Patients with a history of hypertension, diabetes, and cardiovascular disease had a 1.93-fold, 1.30-fold, and 1.76-fold increased risk of arrhythmia after chemotherapy, respectively [OR = 1.93, 95%CI (1.66, 2.24), Pï¼0.00001; OR = 1.30, 95%CI (1.10, 2.52), P = 0.002; OR = 1.76, 95%CI (1.51, 2.05), Pï¼0.00001]. Additionally, the incidence of arrhythmia increased 1.97 times in patients with electrolyte and acid-base balance disorders following chemotherapy [OR = 1.97, 95%CI (1.41, 2.76), Pï¼0.00001]. Chemotherapy-related factors: Seven articles examined the association between chemotherapy drugs and post-chemotherapy arrhythmias. The results indicated that oncology patients were 3.03 times more likely to develop arrhythmias with chemotherapy drugs compared to non-chemotherapy drugs [OR = 3.03, 95%CI (2.59, 3.54), Pï¼0.00001]. Notably, anthracyclines and fluorouracil chemotherapy demonstrated a 2.98-fold and 3.35-fold increased risk of arrhythmia after chemotherapy, respectively [OR = 2.98, 95%CI (2.51, 3.03), Pï¼0.00001; OR = 3.35, 95%CI (2.20, 5.10), Pï¼0.00001]. The risk of arrhythmia after chemotherapy was 1.72 times higher in patients with chemotherapy cycles longer than 4 weeks than those with cycles shorter than 4 weeks [OR = 1.72, 95%CI (1.30, 2.28), P = 0.0001]. Conclusion: The occurrence of arrhythmia after chemotherapy in cancer patients was significantly associated with the patient's age, history of smoking, history of hypertension, history of diabetes, history of cardiovascular disease, chemotherapy drug use, and cycle. However, further high-quality evidence is needed to support these results.
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Primary cardiac tumors in children are rare and mostly benign but can cause significant cardiovascular complications, including arrhythmias. We present a rare case of fetal and neonatal refractory supraventricular tachycardia linked to a probable mitral valve hemangioma, resulting in severe neonatal and maternal morbidity. Despite challenges, pharmacological therapy ultimately successfully managed the condition, highlighting the importance of individualized treatment in such complex cases.
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Background: Ventricular arrhythmia (VA) is a life-threatening condition associated with cardiac sarcoidosis (CS). Right bundle branch block (RBBB) is a common conduction disorder in CS; however, its association with VA remains unknown. Objectives: This study aimed to investigate the relationship between RBBB and VA in patients with CS. Methods: This was a post hoc analysis of ILLUMINATE-CS (Illustration of the Management and Prognosis of Japanese Patients with Cardiac Sarcoidosis), a multicenter, retrospective, and observational study that evaluated the clinical characteristics and prognosis of CS. Eligible patients were divided into two groups based on the presence or absence of RBBB at the time of diagnosis. The primary outcome was serious ventricular arrhythmia events (SVAEs), defined as a combination of sudden cardiac death and documented ventricular fibrillation, sustained ventricular tachycardia, or appropriate implantable cardioverter-defibrillator therapy. Results: Overall, 312 patients were studied, with 155 (49.7%) patients presenting with RBBB (RBBB group). Patients in the RBBB group had a higher prevalence of basal interventricular septum (IVS) thinning and prominent late gadolinium enhancement in the basal IVS on cardiac magnetic resonance imaging than those in the non-RBBB group. During a median follow-up of 3.0 years (IQR: 1.6-6.0 years), 66 patients experienced SVAE. In multivariable Cox regression analysis, the RBBB group was independently associated with a higher incidence of SVAEs (HR: 1.93 [95% CI: 1.14-3.28]; P = 0.015). Conclusions: In patients with CS, RBBB was an independent predictor of SVAEs, which might reflect the specific scar distribution that is predominant in the IVS.
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The significance of physiological regulation in relation to behavioral and emotional regulation is well documented, but primarily in economically advantaged contexts. Few studies have been conducted in low- and middle-income countries. We investigated the feasibility and reliability of measuring autonomic nervous system (ANS) activity and behavior during challenge tasks in 30 children aged 8-10 years in Ghana during two visits, 1 week apart. Completeness of ANS data ranged from 80% to 100% across all tasks. There was low-to-moderate test-retest reliability of video mood induction (VMI) emotion ratings and balloon analog risk task (BART) pumps (r = 0.34-0.52). VMI elicited higher targeted emotion ratings in Visit 2 than Visit 1. Respiratory sinus arrhythmia (RSA) was higher, and pre-ejection period (PEP) was longer at Visit 2 than Visit 1 for baseline and both tasks. RSA was higher at baseline than during the VMI anger scene at Visit 1, whereas PEP was shorter at baseline than during all VMI emotion scenes at Visit 2. RSA was higher at baseline than during BART at both visits. In conclusion, ANS data collection within evocative and arousing challenge tasks was feasible in Ghana, and the tasks were generally reliable and effective in eliciting target emotions and risk-taking behavior in this sample.
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Sistema Nervioso Autónomo , Emociones , Estudios de Factibilidad , Arritmia Sinusal Respiratoria , Humanos , Ghana , Niño , Masculino , Femenino , Sistema Nervioso Autónomo/fisiología , Reproducibilidad de los Resultados , Arritmia Sinusal Respiratoria/fisiología , Emociones/fisiología , Regulación Emocional/fisiología , Conducta Infantil/fisiologíaRESUMEN
The first symptoms of catecholaminergic polymorphic ventricular tachycardia (CPVT) usually occur in childhood and adolescence. 60% of patients experience syncope before the age of 40. Sudden cardiac death (SCD) is the first symptom of the disease in 30-50% of patients with CPVT. Early diagnosis is therefore crucial for the patient's prognosis. The diagnosis of CPVT is confirmed by a normal resting ECG, exclusion of structural heart disease, detection of bidirectional or polymorphic ventricular tachycardia (VT) in the stress ECG and/or detection of a pathogenic mutant in a gene associated with CPVT. Up to 60% of CPVT patients carry changes in the RYR2 gene. This gene encodes the cardiac ryanodine receptor, the most important Ca2+-releasing channel of the sarcoplasmic reticulum, which plays a central role in the contraction and relaxation of the heart muscle. If the function of the ryanodine receptor is impaired, too much calcium enters the cells, which triggers life-threatening arrhythmias. The overactive ryanodine receptor is therefore the main target for gene therapy methods. Even though the development of gene therapy is progressing, there is still no causal therapy available and it is all the more important to make a diagnosis as early as possible, which enables appropriate behavior and adequate symptomatic therapy. The decisive factor here is the evaluation of the genetic analysis in the context of the clinical findings. Based on this, recommendations can be made for preventive measures and the avoidance of specific triggers that could lead to life-threatening arrhythmias.
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Muerte Súbita Cardíaca , Canal Liberador de Calcio Receptor de Rianodina , Taquicardia Ventricular , Humanos , Taquicardia Ventricular/genética , Taquicardia Ventricular/diagnóstico , Taquicardia Ventricular/terapia , Muerte Súbita Cardíaca/etiología , Muerte Súbita Cardíaca/prevención & control , Canal Liberador de Calcio Receptor de Rianodina/genética , Adolescente , Niño , Electrocardiografía , Adulto , Pronóstico , Adulto JovenRESUMEN
Background: Celiac Disease (CD) is characterized by small intestine involvement. However, cardiac manifestations may also be seen in the clinical course. The significance of the QRS prolongation and the presence of QRS fragmentation (fQRS) has been previously studied in many chronic inflammatory disorders as an independent predictor of cardiac manifestations. The study aimed to evaluate the QRS duration and presence of fQRS in patients with CD. Methods: 164 patients with CD and 162 healthy controls were included in the present study. QRS duration and presence of fQRS were calculated from the 12-lead electrocardiogram and compared between groups. The association between these parameters and disease duration was also evaluated. Results: QRS duration was found to be higher in the CD group compared to the control group (83 (76.8-93) vs. 91 (84-94), p<0.001). The presence of fQRS was demonstrated to be higher in the CD group (n=68 (41.5%) vs n=42 (25.9%), p=0.003). Notably, QRS duration was positively correlated with disease duration (Spearman's Rho= 0.47, p<0.001). In addition, disease duration was significantly higher in the fQRS (+) group (60 (23,5-144) vs. 28,5 (15-71,5), p=0.002). Conclusion: This study revealed that QRS prolongation and the presence of fQRS were higher in patients with CD. The presence of these findings may be an indicator of early subclinical cardiac involvement, especially in those with long disease duration. Thus, patients with these ECG findings can be considered for further cardiac evaluation.
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Enfermedad Celíaca , Electrocardiografía , Humanos , Enfermedad Celíaca/fisiopatología , Enfermedad Celíaca/complicaciones , Femenino , Masculino , Adulto , Persona de Mediana Edad , Estudios de Casos y Controles , Adulto Joven , AdolescenteRESUMEN
Background Arrhythmia after coronary artery bypass grafting (CABG) may occur immediately after the abrupt onset of reperfusion via all coronary bypass grafts simultaneously. We investigated whether early reperfusion of the left anterior descending coronary artery before weaning from cardiopulmonary bypass would decrease the frequency of early arrhythmias after CABG. We compared patients undergoing release of the left internal thoracic artery (LITA) graft flow before versus after aortic declamping during CABG. Methodology In total, 109 consecutive patients undergoing CABG were retrospectively analyzed. The heart rhythms after CABG of 46 patients with flow release from LITA before aortic declamping (study group) were compared with 63 patients with complete onset of reperfusion of all coronary bypass grafts simultaneously after aortic declamping (controls). Early arrhythmias were recorded and included atrial fibrillation, ventricular tachycardia, ventricular fibrillation, and arrhythmias necessitating temporary pacemaker support. Results Early arrhythmias occurred in seven out of 46 study group patients with the early release of LITA graft flow compared with 21 out of 63 controls (15.2% vs. 33.3%, p = 0.033). Creatine kinase-myocardial band levels were lower in the study group than in the controls (27.5 ± 58.4 vs. 33.0 ± 48.0, p = 0.004, respectively). Sinus rhythm was achieved in all but three patients before extubation including two in the study group and one in the controls. Conclusions The simple maneuver of releasing LITA graft flow before aortic declamping during CABG allows gradual reperfusion of the myocardium and may ensure early rhythm control.
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Post-vaccination myocarditis is usually moderate and transient, recovering quickly with conservative treatment. Therefore, it is of interest to assess for arrhythmia after CoViD-19 vaccination among Indians. We looked for ECG abnormalities in a small cohort of 50 participants after 52 weeks after receiving the Oxford/AstraZeneca CoViD-19 vaccination. Data shows that post-vaccination myocarditis is typically mild and transient, with most cases resolving swiftly through conservative management. Thus, it is unlikely that this vaccine will induce severe arrhythmias or life-threatening cardiac events in the general population.
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Background: Clinical observations and epidemiological studies suggest a potential linkage between gastroesophageal reflux disease (GERD) and arrhythmias, yet the underlying mechanism remains elusive. This study investigates the causal relationship between GERD and four types of arrhythmia through a genetic lens, employing Mendelian randomization analysis to elucidate the directionality of these associations. Methods: Selected single nucleotide polymorphisms (SNPs) from genome-wide association study (GWAS) data were utilized as instrumental variables. The inverse variance weighting (IVW) method, MR-Egger regression analysis, and the weighted median method were employed in two-sample Mendelian randomization analysis. Horizontal pleiotropy was detected and corrected using the MR-PRESSO test and MR-Egger regression. The stability and reliability of the Mendelian randomization results were assessed using the leave-one-out method, Cochran's Q test, and funnel plots. The causal relationship between GERD and four types of arrhythmias was evaluated using the odds ratio (OR). Results: IVW results indicated that GERD could increase the risk of arrhythmias. A one standard deviation increases in the logarithmically transformed GERD score resulted in a 34% increase in the risk of arrhythmia (OR = 1.34; 95% CI 1.19-1.51; p = 1.66E-06). No significant correlation was found between GERD and other arrhythmias. Conclusion: A causal relationship exists between GERD and arrhythmias, suggesting that GERD increases the risk of developing these arrhythmias.
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INTRODUCTION: The rising prevalence of psychiatric disorders has resulted in a significant increase in the use of antipsychotic medications. These agents may prolong the corrected QT interval (QTc), running the risk of precipitating ventricular arrhythmias, notably Torsades de Pointes (TdP). Current recommendations vary regarding the optimal approach to safe prescribing practices and QTc surveillance for antipsychotics. This review summarizes the current literature addressing these clinical concerns. AREAS COVERED: The physiologic basis of the QTc interval, mechanisms underlying its susceptibility to pharmacological influence, specific risks associated with atypical antipsychotic agents, and recommendations for safe prescription practices. We performed a literature review using Pubmed and Embase databases, searching for 'antipsychotics' and 'torsades de pointes.' EXPERT OPINION: Finding a safe and universally accepted protocol for prescribing antipsychotics remains a persistent challenge in medicine. Predictive models that integrate clinical history with demographic and ECG characteristics can help estimate an individual's susceptibility to therapy-associated risks, including QTc prolongation. Agents such as ziprasidone and iloperidone are significantly more likely to prolong the QTc interval compared to others such as brexpiprazole, cariprazine, olanzapine, and clozapine. A personalized approach using low-risk medications when clinically feasible, and at the lowest efficacious dose, offers a promising path toward safer antipsychotic prescribing.
Antipsychotic medications are used to treat conditions such as schizophrenia and bipolar disorder; however, they can also affect cardiac electrical conduction. This effect on cardiac function increases the risk of a dangerous heart rhythm, which can potentially be fatal. Patients and doctors need to be aware of and monitor for these potential heart-related side effects, although antipsychotics can be very helpful for mental health conditions.
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Atrial fibrillation (AF) is the most common sustained arrhythmia worldwide and remains a major cause of morbidity and mortality. Unfortunately, a significant proportion of patients have persistent AF, for which conventional catheter ablation is less effective. However, convergent ablation has emerged in recent years as a hybrid treatment targeting both the epicardium and endocardium in a multidisciplinary joint cardiothoracic and electrophysiology procedure, with promising efficacy outcomes in recent studies. This treatment is increasingly being performed in the United Kingdom. This review article discusses the rationale and evidence behind convergent ablation, along with factors that need to be considered when setting up a successful ablation service.
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BACKGROUND: Genetic testing for cardiac channelopathies is the standard of care. However, many rare genetic variants remain classified as variants of uncertain significance (VUS) due to lack of epidemiological and functional data. Whether deep protein language models may aid in VUS resolution remains unknown. Here, we set out to compare how 2 deep protein language models perform at VUS resolution in the 3 most common long-QT syndrome-causative genes compared with the gold-standard patch clamp. METHODS: A total of 72 rare nonsynonymous VUS (9 KCNQ1, 19 KCNH2, and 50 SCN5A) were engineered by site-directed mutagenesis and expressed in either HEK293 cells or TSA201 cells. Whole-cell patch-clamp technique was used to functionally characterize these variants. The protein language models, ESM1b and AlphaMissense, were used to predict the variant effect of missense variants and compared with patch clamp. RESULTS: Considering variants in all 3 genes, the ESM1b model had a receiver operator curve-area under the curve of 0.75 (P=0.0003). It had a sensitivity of 88% and a specificity of 50%. AlphaMissense performed well compared with patch-clamp with an receiver operator curve-area under the curve of 0.85 (P<0.0001), sensitivity of 80%, and specificity of 76%. CONCLUSIONS: Deep protein language models aid in VUS resolution with high sensitivity but lower specificity. Thus, these tools cannot fully replace functional characterization but can aid in reducing the number of variants that may require functional analysis.
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Scn1b plays essential roles in the heart, where it encodes ß1 subunits that serve as modifiers of gene expression, cell surface channel activity, and cardiac conductivity. Reduced ß1 function is linked to electrical instability in various diseases with cardiac manifestations and increased susceptibility to arrhythmias. Recently, we demonstrated that loss of Scn1b in mice leads to compromised mitochondria energetics and reactive oxygen species (ROS) production. In this study, we examined the link between increased ROS and arrhythmia susceptibility in Scn1b-/- mice. In addition, ROS scavenging capacity can be overwhelmed during prolonged oxidative stress, increasing arrhythmia susceptibility. Therefore, we isolated whole hearts and cardiomyocytes from Scn1b-/- and Scn1b+/+ mice and subjected them to an oxidative challenge with diamide, a glutathione oxidant. Next, we analyzed gene expression and activity of antioxidant enzymes in Scn1b-/- hearts. Cells isolated from Scn1b-/- hearts died faster and displayed higher rates of ROS accumulation preceding cell death compared to those from Scn1b+/+. Furthermore, Scn1b-/- hearts showed higher arrhythmia scores and spent less time free of arrhythmia. Lastly, we found that protein expression and enzymatic activity of glutathione peroxidase is increased in Scn1b-/- hearts compared to wild-type. Our results indicate that Scn1b-/- mice have decreased capability to manage ROS during prolonged oxidative stress. ROS accumulation is elevated and appears to overwhelm ROS scavenging through the glutathione system. This imbalance creates the potential for altered cell energetics that may underlie increased susceptibility to arrhythmias or other adverse cardiac outcomes.
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BACKGROUND AND PURPOSE: STereotactic Arrhythmia Radioablation (STAR) showed promising results in patients with refractory ventricular tachycardia (VT). However, clinical data is scarce and heterogeneous. The STOPSTORM.eu consortium was established to investigate and harmonize STAR in Europe. The primary goal of this benchmark study was to investigate current treatment planning practice within the STOPSTORM project as a baseline for future harmonization. METHODS: Planning target volumes (PTV) overlapping extra-cardiac organs-at-risk and/or cardiac substructures were generated for three STAR cases. Participating centers were asked to create single fraction treatment plans with 25 Gy dose prescription based on in-house clinical practice. All treatment plans were reviewed by an expert panel and quantitative crowd knowledge-based analysis was performed with independent software using descriptive statistics for ICRU report 91 relevant parameters and crowd dose-volume-histograms. Thereafter, treatment planning consensus statements were established using a dual-stage voting process. RESULTS: Twenty centers submitted 67 treatment plans for this study. In most plans (75%) Intensity Modulated Arc Therapy (IMAT) with 6 MV flattening-filter-free beams was used. Dose prescription was mainly based on PTV D95% (49%) or D96-100% (19%). Many participants preferred to spare close extra-cardiac organs-at-risk (75%) and cardiac substructures (50%) by PTV coverage reduction. PTV D0.035cm3 ranged 25.5-34.6 Gy, demonstrating a large variety of dose inhomogeneity. Estimated treatment times without motion compensation or setup ranged 2-80 minutes. For the consensus statements, strong agreement was reached for beam technique planning, dose calculation, prescription methods and trade-offs between target and extra-cardiac critical structures. No agreement was reached on cardiac substructure dose limitations and on desired dose inhomogeneity in the target. CONCLUSION: This STOPSTORM multi-center treatment planning benchmark study showed strong agreement on several aspects of STAR treatment planning, but also revealed disagreement on others. To standardize and harmonize STAR in the future, consensus statements were established, however clinical data is urgently needed for actionable guidelines for treatment planning.
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Sympathetic hyperactivation and inflammatory responses are the main causes of myocardial ischemiaâreperfusion (I/R) injury and myocardial I/R-related ventricular arrhythmias (VAs). Previous studies have demonstrated that light-emitting diodes (LEDs) could modulate post-I/R neuroinflammation, thus providing protection against myocardial I/R injury. Nevertheless, further applications of LEDs are constrained due to the low penetration depth (< 1 cm) and potential phototoxicity. Low-intensity focused ultrasound (LIFU), an emerging noninvasive neuromodulation strategy with deeper penetration depth (â¼10 cm), has been confirmed to modulate sympathetic nerve activity and inflammatory responses. Sonodynamic therapy (SDT), which combines LIFU with sonosensitizers, confers additional advantages, including superior therapeutic efficacy, precise localization of neuronal modulation and negligible side effects. Herein, LIFU and SDT were introduced to modulate post-myocardial I/R neuroinflammation to protect against myocardial I/R injury. The results indicated that LIFU and SDT inhibited sympathetic neural activity, suppressed the activation of astrocytes and microglia, and promoted microglial polarization towards the M2 phenotype, thereby attenuating myocardial I/R injury and preventing I/R-related malignant VAs. These insights suggest that LIFU and SDT inspire a noninvasive and efficient neuroinflammatory modulation strategy with great clinical translation potential thus benefiting more patients with myocardial I/R in the future. STATEMENT OF SIGNIFICANCE: Myocardial ischemia-reperfusion (I/R) may cause I/R injury and I/R-induced ventricular arrhythmias. Sympathetic hyperactivation and inflammatory response play an adverse effect in myocardial I/R injury. Previous studies have shown that light emitting diode (LED) can regulate I/R-induced neuroinflammation, thus playing a myocardial protective role. However, due to the low penetration depth and potential phototoxicity of LED, it is difficult to achieve clinical translation. Herein, we introduced sonodynamic modulation of neuroinflammation to protect against myocardial I/R injury, based on mitochondria-targeted nanosonosensitizers (CCNU980 NPs). We demonstrated that sonodynamic modulation could promote microglial autophagy, thereby preventing myocardial I/R injury and I/R-induced ventricular arrhythmias. This is the first example of sonodynamic modulation of myocardial I/R-induced neuroinflammation, providing a novel strategy for clinical translation.
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BACKGROUND: Bursting non-sustained cardiac arrhythmia events, are a common observation during sleep. OBJECTIVES: We hypothesized nocturnal arrhythmia episode durations could follow a power-law, whose exponent could predict long-term clinical outcomes. METHODS: We defined 'nocturnal arrhythmia avalanche' (NAA) as any instance of a drop in electrocardiogram (ECG) template-matched R-R intervals ≥30% of R-R baseline, followed by a return to 90% of the baseline. We studied NAA in ECG recordings obtained from the Sleep Heart Health Study (SHHS), the Osteoporotic Fractures in Men Study (MrOS) Sleep and Multi-Ethnic Study of Atherosclerosis (MESA) studies. The association of the nocturnal arrhythmia durations with a power-law distribution was evaluated, and the association of derived power-law exponents (α) with major adverse cardiovascular events and mortality assessed with multivariable Cox regression. RESULTS: n=9176 participants were studied. NAA episodes distribution was with a consistent power-law versus comparator distributions in all datasets studied (Positive log likelihood ratio of power-law vs. exponential in MESA: 83%; SHHS: 69%; MrOS: 81%; power-law vs. log-normal in MESA: 95%; SHHS: 35% and MrOS: 64%). The NAA power law exponent (α) showed a significant association of with adverse CV outcomes (Association with CV mortality: SHHS (HR = 1.39[1.07-1.79], p=0.012); MrOS (HR = 1.42[1.02-1.94], p=0.039; Association with CV events: MESA (HR = 3.46[1.46-8.21], p=0.005)) in multivariable Cox regression, after adjusting for conventional CV risk factors and nocturnal ectopic rate. CONCLUSION: The NAA power-law exponent is a reproducible, predictive marker for incident cardiovascular events and mortality.
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Despite improved childhood survival in congenital heart disease (CHD) due to advances in management, late-onset sudden cardiac death (SCD) from malignant ventricular arrhythmias remains a leading cause of mortality in adults with CHD (ACHD). Preventing SCD in these patients requires an understanding of underlying pathophysiological mechanisms. Many CHD patients experience significant hemodynamic stress on the subpulmonary right ventricle (RV), leading to pathological remodeling. Unlike in acquired heart disease where left ventricle (LV) pathology is prevalent, RV pathologies are crucial in the SCD pathogenesis in CHD patients. This review examines the mechanisms and management of SCD related to subpulmonary RV pathologies in CHD patients.