Ventricular arrhythmia suppression with ivabradine in a patient with catecholaminergic polymorphic ventricular tachycardia refractory to nadolol,flecainide, and sympathectomy

Conventional treatment strategies for catecholaminergic polymorphic ventricular tachycardia (CPVT) include avoidance of strenuous exercise and competitive sports, drugs such as ß-blockers and flecainide and, cervical sympathectomy. An implantable cardioverter-defibrillator (ICD) has been utilized if the response to these strategies is inadequate; however, ICD use in CPVT patients, in addition to usual complications, is associated with an increased risk of life-threatening electrical storm. Ivabradine is a selective inhibitor of hyperpolarization-activated cyclic nucleotide-gated potassium channel 4 generated funny current (I_f), which has been shown to be efficacious in suppression of inappropriate sinus tachycardia, junctional tachycardia, atrial tachycardia, and ventricular ectopy in humans. We report an 18-year-old male with a severe CPVT phenotype refractory to flecainide, nadolol, and sympathectomy who exhibited suppression of ventricular arrhythmias after initiation of ivabradine. These findings are of importance as ivabradine could be an important add-on therapy in CPVT patients who are drug refractory or are unable to continue conventional therapies at the recommended doses.     

抗阻力及倾斜训练在血管迷走性晕厥患儿中的应用

目的探讨抗阻力及倾斜训练在血管迷走性晕厥患儿中的应用。方法选取我院2018年7月至2019年7月收治的92例血管迷走性晕厥患儿作为研究对象,随机将其分为对照组40例和观察组52例,对照组给予常规训练;观察组给予行抗阻力以及倾斜训练,比较两组患儿主、客观疗效以及再晕厥率。结果研究组患儿主、客观疗效均高于对照组,再晕厥率低于对照组,差异有统计学意义(P<0.05)。结论给予血管迷走性晕厥患儿抗阻力及倾斜训练,可降低再晕厥率,主、客观疗效较好,值得临床推广应用。     

α-Adrenoceptor agonists for the treatment of vasovagal syncope: a meta-analysis of worldwide published data

Aim:  The present study was aimed at evaluating present randomized controlled trials (RCTs) regarding the effect of α-adrenoceptor agonists on vasovagal syncope (VVS).
Methods:  According to inclusion and exclusion criteria, articles were selected from medical electronic databases. RCTs were then assessed based on the Juni assessment, and meta-analysis was completed using the Review Manager 4.2 software. Indication to further evaluate effects was the recurrence of syncope during follow-up treatment or a response in the head-up tilt test (HUT) after treatment. The results were stated as odd ratio (OR), with a 95% confidence interval (CI) and a
p <  0.05 significant level.
Results:  In total, six RCTs were selected. Funnel plot analysis showed possible publication bias. Meta-analysis of the six RCTs, including all 165 patients in the treatment group and 164 patients in the control group, indicated that α-adrenoceptor agonists were more effective than placebos in treating VVS (OR = 0.21, 95% CI: 0.06–0.77, p = 0.02). The further, weighted independent t- test disclosed that the weighted mean percentage of responders for midodrine (76.3%± 7.7%) was significantly higher than that for etilefrine (65.5%± 15.4%) ( t = 5.863, p  <  0.001).
Conclusion:  The currently published RCTs support that α-adrenoceptor agonists might be effective for VVS. Midodrine can be regarded as a better choice compared with etilefrine.     

Left Axillary Implantation of Loop Recorder

Background: We compared the clinical course of 10 patients who received an implantable loop recorder (ILR) at a traditional site with 11 patients whose ILRs were implanted via a subpectoral site via a left axillary approach without complications. Methods and Results: R‐wave amplitude was determined at implantation and during follow‐up. Each patient was followed after 7 days to optimize device setting and then at 1 and 3 months. The R‐wave amplitude obtained with the new technique was significantly higher and more stable than that obtained with the standard procedure. Our preliminary experience suggests that axillary access for ILR implantation is feasible, safe, well tolerated, and reliable in terms of sensing function and device performance. Moreover, it is superior aesthetically to the standard approach and carries the potential of minimizing permanent scarring after ILR extraction. (PACE 2010; 999–1002)     

Interventions to reduce vasovagal reactions in blood donors: a systematic review and meta‐analysis

Vasovagal reactions (VVRs) in blood donors have significant implications for the welfare of donors, donor retention and the management of donor sessions. We present a systematic review of interventions designed to prevent or reduce VVRs in blood donors. Electronic databases were searched for eligible randomised trials to March 2015. Data on study design and outcomes were extracted and pooled using random effects meta‐analyses. Sixteen trials met the inclusion criteria: five trials (12 042 participants) of pre‐donation water, eight trials (3500 participants) of applied muscle tension (AMT) and one trial each of AMT combined with water, caffeine, audio‐visual distraction and/or social support. In donors receiving pre‐donation water, the relative risk (RR) compared with controls for VVRs was 0·79 [95% confidence interval (CI) 0·70–0·89, P < 0·0001] and the mean difference (MD) in severity of VVRs measured with the Blood Donation Reactions Inventory (BDRI) score was ?0·32 (95% CI ?0·51 to ?0·12, P < 0·0001). Excluding trials with a high risk of selection bias, the RR for VVRs was 0·70 (95% CI 0·45–1·11, P = 0·13). In donors who received AMT, there was no difference in the risk of chair recline in response to donor distress from controls (RR 0·76, 95% CI 0·53–1·10, P = 0·15), although the MD in BDRI score was ?0·07 (95% CI ?0·11 to ?0·03, P = 0·0005). There was insufficient data to perform meta‐analysis for other interventions. Current evidence on interventions to prevent or reduce VVRs in blood donors is indeed limited and does not provide strong support for the administration of pre‐donation water or AMT during donation. Further large trials are required to reliably evaluate the effect of these and other interventions in the prevention of VVRs.     

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??Vasovagal syncope??VVS?? and postural orthostatic tachycardia syndrome??POTS?? are the two common types of neurally mediated syncope in children. It is sometimes hard to identify the VVS from POTS merely depending on the symptoms. Studies of translational medicine recently have shown that the circulating biomarkers?? hydrogen sulfide??H2S?? and serum iron both have predict value in assessing the therapeutic efficacy and differentiating between VVS and POTS.     

Basic Management of Medical Emergencies: Recognizing a Patient's Distress

Background and OverviewMedical emergencies can happen in the dental office, possibly threatening a patient's life and hindering the delivery of dental care. Early recognition of medical emergencies begins at the first sign of symptoms. The basic algorithm for management of all medical emergencies is this: position (P), airway (A), breathing (B), circulation (C) and definitive treatment, differential diagnosis, drugs, defibrillation (D). The dentist places an unconscious patient in a supine position and comfortably positions a conscious patient. The dentist then assesses airway, breathing and circulation and, when necessary, supports the patient's vital functions. Drug therapy always is secondary to basic life support (that is, PABCD).Conclusions and Clinical ImplicationsPrompt recognition and efficient management of medical emergencies by a well-prepared dental team can increase the likelihood of a satisfactory outcome. The basic algorithm for managing medical emergencies is designed to ensure that the patient's brain receives a constant supply of blood containing oxygen.     

直立性T波改变与血管迷走性晕厥的相关研究

目的探讨无晕厥病史患者出现的直立性T波改变的发生机理及其与血管迷走性晕厥的相关性;方法利用活动平板运动试验初筛出直立性T波改变预检患者,经基础倾斜试验进一步确证,再行硝酸甘油倾斜试验。第2天,阳性患者经随机分组,双盲对照服用安慰剂(=22)或30mg普荼各尔(=21)60min后重复基础倾斜试验、硝酸甘油倾斜试验。结果100例直立性T波改变患者在基础倾斜试验中无1例阳性反应,在随后的NTTT中有43例出现阳性结果。第2天,安慰剂组直立性T波改变及NTTT阳性有比率明显高于普荼各尔组(依次为86.4%∶23.8%,P<0.01,72.7%∶28.6%,P<0.01)。结论直立性T波改变是人体由卧位到立位引起神经-体液变化所致的心室肌复极异常,它是血管迷走性晕厥形成过程中某一阶段出现的一种伴随现象,与血管迷走性晕厥有一定的相关性,心得安等β-受体阻滞剂作为首选药物来治疗直立性T波改变和伴随有直立性T波改变的血管迷走性晕厥患者,收到肯定的临床疗效。