基于相空间形状分析预测房颤终止

识别和描述房颤有可能自发终止还是持续,不仅可以更好地了解心律不齐发作和终止的机制,还可以更有效地治疗持续房颤。本文从非线性角度提取房颤信号特征并预测其能否自发终止。先重建心电信号的相空间,获取相空间中指定庞加莱截面上的点,然后基于形状分析提取刻画庞加莱面上相似点对相对数量的参数ρ,最后基于ρ来分类非终止房颤和可终止房颤。实验研究了一个由Holter心电信号组成的包括训练集和测试集的房颤数据库,结果表明:本文提出的特征参数ρ可正确分类90%的测试集。可见,该方法能从Holter心电信号有效地预测房颤的自发终止。     

老年房颤不同病因的超声心动图分析

目的了解老年房颤的不同病因,发生机制及房颤对心功能,血流动力学的影响。方法分析153例确诊为房颤患者,男88例,女65例:非房颤患者150例,男79例,女71例,年龄均在50～80岁,应用经胸超声心动图及彩色多谱勒观察其心脏结构,各瓣膜病变情况,室壁厚度,左室功能及各瓣口血流情况。结果 1.引起老年房颤病因以退化睦瓣膜钙化占首位,其次高心,慢性风心病,冠心病,心肌病,肺心病。2.房颤组左房扩大,左室射血分数<60%,二尖瓣膜钙化,二尖瓣返流,三尖瓣返流,肺动脉瓣返流,肺高压多见并与对照组均有显著差异(P<0.05)。结论老年房颤病因以退化性瓣膜钙化占首位,绝大多数伴左房扩大,同时房颤使血流动力学发生变化,心功能进一步减退。     

非瓣膜病性心房颤伴缺血性卒中生存与复发因素分析

目的探讨非瓣膜病性房颤伴缺血性卒中患者的生存及复发影响因素。方法回顾性分析1992年～2002年在我院住院的非瓣膜病性房颤伴缺血性卒中患者386例,随访收集患者的有关临床资料,对患者进行生存分析,并研究其复发的有关因素。结果非瓣膜病性房颤伴缺血性卒中患者的10年累计死亡率为51%,复发率为34%,Cox回归单因素发现,高血压,糖尿病,短暂性脑缺血作(TIA),高脂血症,附壁血栓是非瓣膜病性房颤伴缺血性卒中患者复发的危险因素;而阿斯匹林治疗,华法令治疗与血压控制对复发有保护作用。Cox回归多因素分析发现高血压病、TIA发作史与附壁血栓为非瓣膜病性房颤合并缺血性卒中复发的独立危险因素;而阿斯匹林与华法令治疗对非瓣膜病性房颤合并缺血性卒中复发有保护作用。结论高血压病、TIA发作史与附壁血栓为非瓣膜病性房颤合并缺血性卒中复发的独立危险因素;而阿斯匹林与华法令治疗对非瓣膜病性房颤合并缺血性卒中复发有保护作用。     

The difference-sign runs length distribution in testing for serial independence

We investigate the sequence of difference-sign runs length of a time series in the context of non-parametric tests for serial independence. This sequence is, under suitable conditioning, a stationary sequence and we prove that the normalized correlation of two consecutive runs length is small (≈0.0427). We use this result in a test based on the relative entropy of the empirical distribution of the runs length. We investigate the performance of the test in simulated series and test serial independence of cardiac data series in atrial fibrillation.     

Older age and a higher EHRA score allow higher levels of frailty syndrome to be predicted in patients with atrial fibrillation

Background: There is no research that evaluates the relationship between the severity of the symptoms of atrial fibrillation (AF), the presence of frailty syndrome and acceptance of the illness.

Methods: The study included 132 patients aged 72.7?±?6.73 with diagnosed AF. The severity of the symptoms of AF was determined according to European Heart Rhythm Association (EHRA) guidelines, frailty syndrome was assessed using the Tilburg frailty indicator (TFI) and the acceptance of the illness was assessed using the acceptance of illness scale (AIS). A standard statistical comparison and multiple regression analysis using the stepwise method were performed.

Results: In patients with AF, frailty was 5.31?±?2.69 (TFI). Frailty syndrome was diagnosed in 59.8% of the AF patients who had a score of 7.17?±?1.72. A higher level of EHRA score was connected with a smaller degree of the acceptance of the illness p?=?0.0000. The multiple regression model indicated that age (p?=?0.0009) and the severity of the symptoms (p?=?0.0001) are important predictors of frailty syndrome.

Conclusions: There is a relationship between the presence of frailty syndrome and the intensity of the symptoms and the acceptance of AF. Age and the EHRA score permitted higher levels of frailty syndrome to be predicted.