Fractal character of the electrocardiogram: Distinguishing heart-failure and normal patients

Statistical analysis of the sequence of heartbeats can provide information about the state of health of the heart. We used a variety of statistical measures to identify the form of the point process that describes the human heartbeat. These measures are based on both intervent intervals and counts, and include the intervent-interval histogram, interval-based periodogram, rescaled range analysis, the event-number histogram, Fano-factor, Allan Factor, and generalized-rate-based periodogram. All of these measures have been applied to data from both normal and heart-failure patients, and various surrogate versions thereof. The results show that almost all of the interevent-interval and the long-term counting statistics differ in statistically significant ways for the two classes of data. Several measures reveal 1/f-type fluctuations (long-duration power-law correlation). The analysis that we have conducted suggests the use of a conveniently calculated, quantitative index, based on the Allan factor, that indicates whether a particular patient does or does not suffer from heart failure. The Allan factor turns out to be particularly useful because it is easily calculated and is jointly responsive to both short-term and long-term characteristics of the heartbeat time series. A phase-space reconstruction based on the generalized heart rate is used to obtain a putative attractor's capacity dimension. Though the dependence of this dimension on the embedding dimension is consistent with that of a low-dimensional dynamical system (with a larger apparent dimension for normal subjects), surrogate-data analysis shows that identical behavior emerges from temporal correlation in a stochastic process. We present simulated results for a purely stochastic integrate-and-fire model, comprising a fractal-Gaussian-noise kernel, in which the sequence of heartbeats is determined by level crossings of fractional Brownian motion. This model characterizes the statistical behavior of the human electrocardiogram remarkably well, properly accounting for the behavior of all of the measures studied, over all time scales.     

千年桐抗心肌缺血的药理

实验结果表明，千年桐叶水提醇沉液能降低小鼠机体耗氧量，延长夹闭气管小鼠心电消失时间，对抗垂体后叶素致家兔心电图改变和结扎冠脉致大鼠心电图Ｓ－Ｔ段抬高。促癌试验表明千年桐无促癌作用。急性毒性试验表明千年桐叶毒性很小。     

扩张型心肌病和缺血性心肌病的区域性QT间期差比较及临床意义探讨

目的　探讨区域性QT间期差值 (QTrd)能否作为鉴别扩张型心肌病和缺血性心肌病引起的ST -T改变的一项指标。方法　将 6 4例因体表心电图出现ST段异常改变 ,经冠状动脉造影确诊为缺血性心肌病或扩张型心肌病的患者分为缺血性心肌病组和扩张型心肌病组 ,把体表心电十二导联的心电图分为Ⅰ、AVL ,Ⅱ、Ⅲ、AVF ,V2～ 4,V5～ 6四个区域测量QTrd并进行分析比较。结果　在Ⅰ、AVL区域 ,各组都有部份QTrd≥ 4 0ms;Ⅱ、Ⅲ、AVF ,V2～ 4,V5～ 6三个区域 ,有一个区域的QTrd≥ 4 0ms的百分比 ,在扩张型心肌病组为81% ,缺血性心肌病组无一例大于 4 0ms。结论　扩张型心肌病时 ,如心电图出现ST异常改变 ,在Ⅱ、Ⅲ、AVF ,V2～ 4,V5～ 6这三个区域中 ,有一区域的QTrd >4 0ms ,则心肌扩张引起缺血的可能性大 ,如这三个区域中的QTrd都小于 4 0ms ,可能为冠状动脉病变引起心肌缺血的表现。     

思瑞康对心电图的影响

目的：研究思瑞康引起心电图改变的特征及其与服药时间、剂量之间的关系，并与氯氮平引起心电图改变作比较。方法：对符合CCMD－3诊断标准的精神分裂症患，在服药前、服药后4周、6周分别作心电图检查，记录服药剂量与心电图改变的规律，并在思瑞康组与氯氮平组之间作显性检验。结果：思瑞康引起的心电图改变主要为窦性心动过速、呈有T波变化，但发生率低于氯氮平，一般不影响治疗，并且与服天数、剂量大小无关。结论：思瑞康可引起心电图改变，其程度发生率低于氯氮平。     

Three-dimensional distribution of myocardial fibrosis in the new J-2-N cardiomyopathic hamster: Comparison with electrocardiographic findings

Summary Using the new J-2-N strain of cardiomyopathic hamster obtained by cross-breeding Bio 14.6 and Golden hamsters, we investigated the threedimensional distribution of ventricular myocardal fibrosis and compared it with electrocardiographic (ECG) changes. Twelve-lead ECG recordings were made by our own method. The hearts were cut into serial sections and subjected to light microscopic examination. The distribution, density, and volume of myocardial interstitial fibrosis and replacement fibrosis due to myocardial degeneration (F%) were visualized three-dimensionally using the TRI system (TRI; Three-Dimensional Reconstruction Image; Ratoc System Engineering, Tokyo, Japan). Thirty-two J-2-N hamsters were divided into two groups; one group comprised 17 animals with normal hearts and normal ECG findings similar to those of Golden hamsters, and the other group of 15 hamsters had dilated hearts and abnormal ECG findings. In the normal hearts, the F% values for the right ventricle, left ventricle, and ventricular septum were 6.4 ± 0.94, 6.5 ± 0.95, and 6.5 ± 0.98 (mean ± SD), respectively. The dilated hearts showed marked fibrosis, which was distributed mainly in the middle layer of the left ventricle and the ventricular septum. The corresponding F% values for the hamsters with cardiac enlargement were 19 ± 2.6, 19 ± 1.8, and 22 ± 3.2 (mean ± SD), respectively. Replacement of myocytes by fibrosis seemed to correspond to abnormal Q waves in the anterior chest leads and left axis deviation of the QRS complex.     

从流行病学看全国肺心病心电图诊断标准

为评价我国肺心病心电图诊断标准在流行病学调查中的实用性,对流行病学调查查出的1847例慢性阻塞性肺病患者心电图按我国与世界卫生组织肺心病心电图诊断标准作比较分析.结果按我国标准肺心病的检出率为23.66%;而按世界卫生组织标准确诊和可疑者共8.61%.如将标准定为P_I≥0.25mV和QRS电轴≥ 100°为阳性,除V_1呈qR或qr可1项定性,其余指标需2项以上阳性始可诊断,则肺心病检出率为6.06%;而全部指标皆1项阳性即可诊断者为20.19%.认为我国现行肺心病心电图诊断标准可能偏松.     

小儿慢性房性心动过速心电图及临床分析(附31例报告)

总结了３１例小儿慢性房性心动过速的心电图及临床特点。首次发病年龄２个月～１１．５岁，病程持续３３天～３年零２０天。心力衰竭１３例，２９例无器质性心脏病。心电图可见异位Ｐ波，房率１１５～２５０次／分，昼夜变化差４６～１３２次／分。伴房室传导阻滞１９例。药物治疗９３次，转复９例。对房率快、心功能减低的小婴儿应适当用药     

Genetic-algorithm cancellation of sinusoidal powerline interference in electrocardiograms

The paper describes a method, based on a genetic algorithm, to remove sinusoidal powerline interference in electrocardiograms. There is a report on the use of the genetic algorithm to remove powerline interference for two different types of interference, powerline interference with frequency drift, and interference with frequency drift as well as third- harmonic distortion. The studies are conducted on electrocardiograms with simulated interference and also on actual noisy electrocardiogram records. The results obtained using the genetic algorithm in these cases of interference are presented.     

头针"额旁1线"对心律失常大鼠心电图的影响

目的：观察头针“额旁1线”对氯化钡所致的实验性心律失常大鼠的作用。方法：在氯化钡所致的实验性心律失常模型上，针刺大鼠头部双侧“额旁1线”区域，并给予电针刺激，记录各组大鼠心电图，观察不同时刻心率和心律失常恢复时间。结果：头针“额旁1线”对大鼠心律失常具有明显的改善作用，头针可有效调整大鼠率，缩短心律失常持续时间，结论：头针有显的抗实验性心律失常作用。说明“额旁1线”作为头部胸腔放射区域，与心脏功能活动有着密切关系。     

传染性非典型肺炎的心脏表现

目的:探讨传染性非典型肺炎(非典)患者的心脏改变及可能的影响因素。方法:普通型非典组91例,重型非典组23例,入院后第1日检测心肌酶和心电图,部分病人动态观察心肌酶和心电图变化。结果:重型非典组心肌酶异常发生率为78%,明显高于普通型非典组的47%,两组肌酸激酶值比较差异无统计学意义,但重型非典组的乳酸脱氢酶显著升高。普通型非典组心肌酶绝大多数在4周内恢复正常,而重型非典组尤其是死亡病例心肌酶进行性升高。心电图异常率23%、43%(P>0.05),但重型非典组心电图异常表现复杂,病情严重。结论:非典患者发生心脏损害的机会较大,程度较轻,可能与疾病本身有关,重型非典病人尤其是死亡病人的心脏损害程度加重,并可能与年龄和基础疾病有关。