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Cardioneuroablation (CNA) is being increasingly used to treat patients with vasovagal syncope (VVS). Bradycardia, in the cardioinhibitory subtype of VVS, results from transient parasympathetic overactivity leading to sinus bradycardia and/or atrioventricular block. By mitigating parasympathetic overactivity, CNA has been shown to improve VVS symptoms in clinical studies with relatively small sample sizes and short follow-up periods (<5 years) at selected centers. However, CNA may potentially tip the autonomic balance to a state of sympathovagal imbalance with attenuation of cardiac parasympathetic activity. A higher heart rate is associated with adverse cardiovascular events and increased mortality in healthy populations without cardiovascular diseases. Chronic sympathovagal imbalance may also affect the pathophysiology of spectra of cardiovascular disorders including atrial and ventricular arrhythmias. This review addresses potential long-term pathophysiological consequences of CNA for VVS. [Display omitted] [ABSTRACT FROM AUTHOR]

Myocardial calcium (Ca2+) signaling plays a crucial role in contractile function and membrane electrophysiology. An abnormal myocardial Ca2+ transient is linked to heart failure and ventricular arrhythmias. At the subcellular level, the synchronous release of Ca2+ sparks from sarcoplasmic Ca2+ release units determines the configuration and amplitude of the global Ca2+ transient. This narrative review evaluates the role of aberrant Ca2+ release synchrony in the pathophysiology of cardiomyopathies and ventricular arrhythmias. The potential therapeutic benefits of restoration of Ca2+ release synchrony in heart failure and ventricular arrhythmias are also discussed. [Display omitted] [ABSTRACT FROM AUTHOR]

Management of ventricular arrhythmia in structural heart disease is complicated by the toxicity of the limited antiarrhythmic options available. In others, proarrhythmia and deleterious hemodynamic and noncardiac effects prevent practical use. This necessitates new thinking in therapeutic agents for ventricular arrhythmia in structural heart disease. Ivabradine, a funny current (If) inhibitor, has proven safety in heart failure, angina, and inappropriate sinus tachycardia. Although it is commonly known that funny channels are primarily expressed in the sinoatrial node, atrioventricular node, and conducting system of the ventricle, ivabradine is known to exert effects on metabolism, ion homeostasis, and membrane electrophysiology of remodeled ventricular myocardium. This review considers novel concepts and evidence from clinical and experimental studies regarding this paradigm, with a potential role of ivabradine in ventricular arrhythmia. [ABSTRACT FROM AUTHOR]

Adenosine monophosphate-activated protein kinase (AMPK) is the cellular stress-sensing molecule. Apart from maintaining cellular energy balance, AMPK controls expression and regulation of ion channels and ion transporters, including cytosolic Ca2+ handling proteins. Emerging evidence suggests that metabolic impairment plays a crucial role in the pathogenesis of atrial fibrillation. AMPK activation is thought to be protective by preventing metabolic stress, favorably modulating membrane electrophysiology including cytosolic Ca2+ dynamics; preventing cellular growth; and hypertrophic remodeling. This review considers current concepts and evidence from clinical and experimental studies regarding the role of AMPK in atrial fibrillation. [ABSTRACT FROM AUTHOR]

Abnormal cardiac metabolism or cardiac metabolic remodeling is reported before the onset of heart failure with reduced ejection fraction (HFrEF) and is known to trigger and maintain the mechanical dysfunction and electrical, and structural abnormalities of the ventricle. A dysregulated cardiac autonomic tone characterized by sympathetic overdrive with blunted parasympathetic activation is another pathophysiological hallmark of HF. Emerging evidence suggests a link between autonomic nervous system activity and cardiac metabolism. Chronic β-adrenergic activation promotes maladaptive metabolic remodeling whereas cholinergic activation attenuates the metabolic aberrations through favorable modulation of key metabolic regulatory molecules. Restoration of sympathovagal balance by neuromodulation strategies is emerging as a novel nonpharmacological treatment strategy in HF. The current review attempts to evaluate the 'neuro-metabolic axis' in HFrEF and whether neuromodulation can mitigate the adverse metabolic remodeling in HFrEF. [Display omitted] [ABSTRACT FROM AUTHOR]

Mitigation of cardiac autonomic dysregulation by neuromodulation technologies is emerging as a new therapeutic modality of heart failure (HF). This recent progress has necessitated the identification of a biomarker for the quantification of sympathovagal balance, the potential target of 'neuromodulation' strategies. The currently available autonomic nervous system assessment parameters do not truly reflect the sympathovagal balance of the ventricle. Protein kinase A (PKA) is an intracellular enzyme that plays a major role in the pathophysiology of functional and structural ventricular remodeling in HF. Interestingly, sympathetic and parasympathetic activations exert reciprocal influence on the activity of PKA. The current review attempts to evaluate the potential concept and feasibility of using in vitro assessment of PKA activity as a marker of sympathovagal balance in HF. [Display omitted] [ABSTRACT FROM AUTHOR]

Empagliflozin (EMPA) reduces heart failure hospitalization and mortality. The benefit in terms of ventricular arrhythmia and contractility has not been explored. To determine the direct effects of EMPA on ventricular arrhythmia and cardiac contractility in an ex-vivo model of global ischemia-reperfusion (I/R). Langendorff-perfused rabbit hearts were subjected to 30 min of complete perfusion arrest and reperfusion. Either EMPA (1 μM) or normal saline (controls) was then infused into the perfusate in a randomized fashion. Ten minutes following drug infusion, calcium imaging was performed. At the end of each experiment, the heart was electrically stimulated 5 times to assess the inducibility of ventricular fibrillation (VF). In a separate series of experiments, left ventricular (LV) pressure and epicardial NADH fluorescence were simultaneously recorded. LV specimens were then collected for western blotting. Post-ischemia, EMPA treatment was associated with reduction in the induction of VF >10s (rate of induction: 16.7 ± 3.3% vs. 60 ± 8.7% in control hearts, p = 0.003), improvement of LV developed pressure (LVDP; 68.10 ± 9.02% vs. 47.61 ± 5.15% in controls, p = 0.03) and reduction of NADH fluorescence (87.42 ± 2.79% vs. 112.88 ± 2.27% in control hearts, p = 0.04) along with an increase in NAD+/NADH ratio (2.75 ± 0.55 vs. 1.09 ± 0.32 in the control group, p = 0.04) A higher calcium amplitude alternans threshold was also observed with EMPA-treatment (5.42 ± 0.1 Hz vs. 4.75 ± 0.1 Hz in controls, p = 0.006). Sodium-glucose co-transporter-2 (SGLT2) expression was not detected in LV tissues. EMPA treatment reduced ventricular arrhythmia vulnerability and mitigated contractile dysfunction in the global I/R model while improving calcium cycling and mitochondrial redox by SGLT2-independent mechanisms. In normoxic conditions, NADH is generated by the reduction of NAD+ in metabolic pathways by glucose oxidation and Krebs cycle. NADH is oxidized to NAD+ by ETC to produce ATP. ETC dysfunction during hypoxia (Red dotted arrow) is associated with the accumulation of NADH. Improvement of ETC function by EMPA (Blue solid arrow) leads to increase in NAD+/NADH ratio, improvement of contractile function, improvement of cytosolic calcium dynamics, and reduction of vulnerability to ventricular arrhythmias. Glu: Glucose, Pyr: Pyruvate, TCA cycle: Tricarboxylic acid cycle (Krebs cycle), ETC: Electron transport chain, EMPA: Empagliflozin, I/R: Ischemia-reperfusion, SR: Sarcoplasmic reticulum. [Display omitted] • Cardioprotective effects of Empagliflozin were evaluated in a model of global ischemia-reperfusion (I/R) • Empagliflozin increased contractility and decreased ventricular arrhythmia vulnerability • Improvements in mitochondrial redox state and cytosolic calcium dynamics were also noted with Empagliflozin treatment • In our Langendorff model, the cardioprotective effects of Empagliflozin were independent of SGLT2 inhibitory actions • These cardioprotective actions may explain the favorable effects of SGLT2i agents in heart failure which is independent of blood sugar control [ABSTRACT FROM AUTHOR]

Background: Statins are the most widely prescribed hypolipidaemic drugs for coronary artery disease (CAD) patients, but have been found to cause muscle and nerve related adverse effects which can affect patient satisfaction with treatment. Literature on treatment satisfaction among statin users, especially from resource-limited settings is inadequate. The aim of this cross-sectional study was to assess the level of satisfaction with treatment among statin users and evaluate the relationship between adverse effects experienced by patients and their satisfaction with the medication.Methods: This study included 300 adult CAD patients visiting the cardiology department of a tertiary care hospital in the northern region of India, who were prescribed statins for their diagnoses. An interviewer administered, validated and standardised Treatment Satisfaction Questionnaire for Medication (version 1.4) was used for data collection.Results: Around three quarters of the population reported being overall satisfied with their medication. Mean scores were calculated for Effectiveness, Convenience, Side-Effects and Global Satisfaction. The patients reported high scores (above 60%) for all domains. Those experiencing any adverse effect were found to be more likely to report lower effectiveness. Additionally, medication effectiveness showed a positive correlation with overall treatment satisfaction.Conclusions: The study shows that treatment satisfaction is critical to gauge patient experiences with the treatment which can impact medication adherence and compliance. It's a crucial measure especially among CAD and other chronic disease patients since greater satisfaction can improve clinical outcomes. More research is warranted to better understand the relationship between medication effectiveness and treatment satisfaction. [ABSTRACT FROM AUTHOR]