经食管心房调搏对阵发性室上性心动过速的诊断价值

目的 探讨经食管心房调搏对阵发性室上性心动过速的分型及定位诊断价值。方法 回顾性分析食管心房调搏对193例阵发性室上性心动过速分型及定位诊断结果，并与心内电生理检查诊断结果比较。结果 经食管心房调搏对慢-快型AVNRT及顺向性AVRT的诊断敏感性、特异性、准确性均较高，对少见型AVNRT的诊断敏感性低(25％)。结论 阵发性室上性心动过速发作时食管与体表心电图P^-波起始与极性是诊断阵发性室上性心动过速的关键。经食管心房调搏对心动过速旁道定位误诊原因主要是心动过速时体表心电图P^-波往往与T波融合，导致V1、I导联P^-波极性及V1导联P^-波起始部形态改变。     

The Utility of Rapid Atrial Pacing Immediately Post-TAVR to Predict the Need for Pacemaker Implantation

ObjectivesThe aim of this study was to determine the utility of rapid atrial pacing immediately after transcatheter aortic valve replacement (TAVR) to predict the need for permanent pacemaker implantation (PPI).BackgroundRisk stratification for patients without high-grade atrioventricular block (AVB) after TAVR is imprecise and based on anatomic considerations, electrocardiographic characteristics, and clinical suspicion. A more reliable assessment is necessary to minimize inpatient rhythm monitoring and/or reduce unnecessary PPI.MethodsConsecutive patients undergoing TAVR at 2 centers were included. After valve implantation in patients without pacemakers who did not have complete heart block or atrial fibrillation, the temporary pacemaker was withdrawn from the right ventricle and placed in the right atrium. Rapid atrial pacing was performed from 70 to 120 beats/min, and patients were assessed for the development of Wenckebach AVB. Patients were then followed for clinical outcomes, including PPI.ResultsA total of 284 patients were included. Of these, 130 (45.8%) developed Wenckebach AVB. There was a higher rate of PPI within 30 days of TAVR among the patients who developed Wenckebach AVB (13.1% vs. 1.3%; p < 0.001), with a negative predictive value for PPI in the group without Wenckebach AVB of 98.7%. A greater percentage of patients receiving self-expanding valves required PPI than those receiving a balloon-expandable valves (15.9% vs. 3.7%; p = 0.001), though these rates were still relatively low among patients who did not develop Wenckebach AVB (2.9% and 0.8%).ConclusionsAtrial pacing post-TAVR is easily performed and can help identify patients who may benefit from extended rhythm monitoring. Patients who did not develop pacing-induced Wenckebach AVB demonstrated an extremely low likelihood of PPI.     

Effects of electroacupuncture on gastric mucosal blood flow and transmucosal potential difference in stress rats

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人工智能与心律失常研究进展

近年来,人工智能在心律失常领域展现出巨大的潜力。智能研究和心律失常的结合给疾病的预防、诊断和治疗带来巨大变革。本文将就人工智能分别在心律失常诊断、挖掘疾病新特征、建立疾病预测模型、局限性及展望四个方面作一阐述。     

Mechanism of Pacemaker Activity in Zebrafish DC2/4 Dopaminergic Neurons

Zebrafish models are used increasingly to study the molecular pathogenesis of Parkinson''s disease (PD), owing to the extensive array of techniques available for their experimental manipulation and analysis. The ascending dopaminergic projection from the posterior tuberculum (TPp; diencephalic populations DC2 and DC4) to the subpallium is considered the zebrafish correlate of the mammalian nigrostriatal projection, but little is known about the neurophysiology of zebrafish DC2/4 neurons. This is an important knowledge gap, because autonomous activity in mammalian substantia nigra (SNc) dopaminergic neurons contributes to their vulnerability in PD models. Using a new transgenic zebrafish line to label living dopaminergic neurons, and a novel brain slice preparation, we conducted whole-cell patch clamp recordings of DC2/4 neurons from adult zebrafish of both sexes. Zebrafish DC2/4 neurons share many physiological properties with mammalian dopaminergic neurons, including the cell-autonomous generation of action potentials. However, in contrast to mammalian dopaminergic neurons, the pacemaker driving intrinsic rhythmic activity in zebrafish DC2/4 neurons does not involve calcium conductances, hyperpolarization-activated cyclic nucleotide-gated (HCN) channels, or sodium leak currents. Instead, voltage clamp recordings and computational models show that interactions between three components – a small, predominantly potassium, leak conductance, voltage-gated sodium channels, and voltage-gated potassium channels – are sufficient for pacemaker activity in zebrafish DC2/4 neurons. These results contribute to understanding the comparative physiology of the dopaminergic system and provide a conceptual basis for interpreting data derived from zebrafish PD models. The findings further suggest new experimental opportunities to address the role of dopaminergic pacemaker activity in the pathogenesis of PD.SIGNIFICANCE STATEMENT Posterior tuberculum (TPp) DC2/4 dopaminergic neurons are considered the zebrafish correlate of mammalian substantia nigra (SNc) neurons, whose degeneration causes the motor signs of Parkinson''s disease (PD). Our study shows that DC2/4 and SNc neurons share a number of electrophysiological properties, including depolarized membrane potential, high input resistance, and continual, cell-autonomous pacemaker activity, that strengthen the basis for the increasing use of zebrafish models to study the molecular pathogenesis of PD. The mechanisms driving pacemaker activity differ between DC2/4 and SNc neurons, providing: (1) experimental opportunities to dissociate the contributions of intrinsic activity and underlying pacemaker currents to pathogenesis; and (2) essential information for the design and interpretation of studies using zebrafish PD models.     

Preserving GABAergic interneurons in acute brain slices of mice using the N-methyl-<Emphasis Type="Italic">D</Emphasis>-glucamine-based artificial cerebrospinal fluid method

Defects in the function and development of GABAergic interneurons have been linked to psychiatric disorders, so preservation of these interneurons in brain slices is important for successful electrophysiological recording in various ex vivo methods. However, it is difficult to maintain the activity and morphology of neurons in slices from mice of >30 days old. Here we evaluated the N-methyl-D-glucamine(NMDG)-based artificial cerebrospinal fl uid(a CSF) method for the preservation of interneurons in slices from mice of up to ~6 months old and discussed the steps that may affect their quality during slicing. We found that the NMDG-a CSF method rescued more cells than sucrose-a CSF and successfully preserved different types of interneurons including parvalbumin- and somatostatin-positive interneurons. In addition, both the chemical and electrical synaptic signaling of interneurons were maintained. These results demonstrate that the NMDG-a CSF method is suitable for the preservation of interneurons, especially in studies of gap junctions.     

Implantable defibrillator event rates in patients with unexplained syncope and inducible sustained ventricular tachyarrhythmias: a comparison with patients known to have sustained ventricular tachycardia

OBJECTIVES

To assess the clinical significance of inducible ventricular tachyarrhythmias among patients with unexplained syncope.

BACKGROUND

Induction of sustained ventricular arrhythmias at electrophysiology study in patients with unexplained syncope and structural heart disease is usually assigned diagnostic significance. However, the true frequency of subsequent spontaneous ventricular tachyarrhythmias in the absence of antiarrhythmic medications is unknown.

METHODS

In a retrospective case-control study, the incidence of implantable cardiac defibrillator (ICD) therapies for sustained ventricular arrhythmias among patients with unexplained syncope or near syncope (syncope group, n = 22) was compared with that of a control group of patients (n = 32) with clinically documented sustained ventricular tachycardia (VT). Sustained ventricular arrhythmias were inducible in both groups and neither group received antiarrhythmic medications. All ICDs had stored electrograms or RR intervals. Clinical variables were similar between groups except that congestive cardiac failure was more common in the syncope group.

RESULTS

Kaplan-Meier analysis of the time to first appropriate ICD therapy for syncope and control groups produced overlapping curves (p = 0.9), with 57 ± 11% and 50 ± 9%, respectively, receiving ICD therapy by one year. In both groups, the induced arrhythmia was significantly faster than spontaneous arrhythmias, but the cycle lengths of induced and spontaneous arrhythmias were positively correlated (R = 0.6, p < 0.0001). During follow-up, three cardiac transplantations and seven deaths occurred in the syncope group, and two transplantations and five deaths occurred in the control group (36-month survival without transplant 52 ± 11% and 83 ± 7%, respectively, p = 0.03).

CONCLUSIONS

In patients with unexplained syncope, structural heart disease and inducible sustained ventricular arrhythmias, spontaneous sustained ventricular arrhythmias occur commonly and at a similar rate to patients with documented sustained VT. Thus, electrophysiologic testing in unexplained syncope can identify those at risk of potentially life-threatening tachyarrhythmias, and aggressive treatment of these patients is warranted.