Surgery for Ventricular Tachycardia

The treatment of drug-refractory chronic ventricular tachycardia (VT) has undergone a revolution over the last 50 years. We now have automatic implantable cardioverter defibrillator therapy with pace-terminating capabilities, and catheter ablation of VT has refined mapping and improved methods of lesion generation. Between 1980 and 1993, Houston Methodist Hospital became a leader in the diagnosis and surgical ablation of VT and other arrhythmias. This is a brief account of that period and some of the experiences and lessons that have led to significant advances used today.     

Meta‐Analysis of P‐Wave Dispersion Values in Healthy Individuals: The Influence of Clinical Characteristics

Background: P‐wave dispersion (Pd) is an appealing marker for predicting the risk of developing atrial fibrillation. At present, no definitive cutoff value has been determined as to the diagnosis of high‐risk patients. Our aims were to evaluate P‐wave parameters of healthy subjects published in the literature, determine normal range and weighted means of Pd and P‐wave parameters, and investigate the influences of gender, age, and BMI on the weighted results. Methods: A systematic search of studies published in PubMed was conducted. Only studies which included control groups of healthy individuals were included. Results: Of the 657 studies initially identified, 80 were eligible for inclusion. The total number of participants was 6,827. The highest reported Pd values were 58.56 ± 16.24  ms; the lowest were 7 ± 2.7  ms. The weighted mean was 33.46 ± 9.65  ms; weighted median was 32.2  ms. Gender and age were not found to be associated with significant influences on P‐wave parameter values. High‐normal BMI was not found to be associated with increased P‐wave parameter values. Conclusions: Pd, Pmax, and Pmin span a wide range of values in healthy individuals. Seemingly, abnormal values were often reported in healthy adults. The high variability of P‐wave parameters in healthy individuals, and overlapping of the results with those reported for patients with increased risk for atrial fibrillation, might suggest that this technique has limited sensitivity and specificity. The variability between studies may stem from methodological issues and, therefore, there is a definite need for methodological standardization of Pd measurements. Ann Noninvasive Electrocardiol 2012;17(1):28–35     

镁离子在治疗心律失常中的研究进展

Mg^2＋是人体内重要的电解质离子，是人体细胞内含量第二丰富的阳离子，具有复杂的调节机制，对维持机体新陈代谢及其他生理功能具有极其重要的作用。目前已发现人体内超过300种酶的作用离不开其参与，其中包括Mg^2＋-K^＋-ATP酶、Ca^2＋-ATP酶等。临床上利用Mg^2＋调节这些酶的活性等特点，将Mg^2＋作为一种预防和治疗心律失常的药物在很多方面运用，但其规范化运用仍有待进一步明确。现将Mg^2＋在心律失常中的运用综述如下。     

心律平与胺碘酮治疗心律失常疗效比较的Meta分析

目的 评价文献中运用心律平与胺碘酮治疗心律失常的疗效.方法 运用计算机检索Pubmed、EMbase、Cochrane图书馆、中国生物医学文献数据库中关于心律平和胺碘酮在治疗心律失常疗效的随机对照试验,将检索时限定为2000年1月～2014年7月.对检索到的论文进行客观质量评价,应用Cochrane协作网提供的Rev Man 5.3软件进行Meta分析.结果 通过药物静脉注射给药,2组心律失常总有效率差异有统计学意义(OR=1.68,95％ CI:1.25 ～2.26,P＜0.0001);药物口服给药,2组心律失常总有效率差异有统计学意义(OR=1.49,95％ CI:1.09 ～ 2.03,P=0.010);2组不良反应发生率比较差异无统计学意义(OR=0.85,95％ CI:0.62 ～ 1.16,P＞0.05).结论 胺碘酮组治疗心率失常的疗效优于心律平,但对于药物的不良反应率并不增加.     

Bufalin,a bufanolide steroid from the parotoid glands of the Chinese toad,suppresses hERG K+ currents expressed in HEK293 cells

In this study, we investigated the effect of bufalin on the human ether‐à‐go‐go‐related gene (hERG) K⁺ channels using the perforated patch recording technique. We measured a half‐maximal inhibitory concentration (IC₅₀) of 24.83 μM and maximal inhibitory effect of 39.45 ± 1.14% with bufalin. These findings suggest that bufalin is a potent hERG K⁺ channel blocker and may provide a new way for understanding Chan Su‐induced arrhythmia.     

Fathering across contexts: The moderating role of respiratory sinus arrhythmia in predicting toddler emotion regulation

Caregivers play an integral role in promoting children's emotion regulation, while children's individual physiology affects how they respond to the caregiving environment. Relatively little is known about how fathering influences toddler emotion regulation, particularly within African American and low-income communities, where risk related to the development of emotion regulation is higher. This study investigated relations among fathering, toddler parasympathetic regulation, and toddler emotion regulation in a sample of 92 families. Fathering was assessed during two interactions: engagement following a stressor during a triadic task and a dyadic play task. Respiratory sinus arrhythmia (resting and reactivity) was obtained as an index of toddler parasympathetic arousal. Findings demonstrated an association between fathers’ engagement poststressor and toddler emotion regulation. Toddler RSA moderated this association: toddlers with elevated levels of resting RSA benefitted from parenting engagement following a stressor. Fathering during play did not relate to toddler emotion regulation. The importance of fathering and physiologic contexts in early regulatory development is discussed.