Effects of metoprolol on heart rate in patients with digitalis treated chronic atrial fibrillation

Adequate control of ventricular rate in patients with chronic atrial fibrillation (AF) may not be achieved with digitalis alone. In the present study the additional effect of two different doses (50 mg and 50 + 50 mg) of oral metoprolol, a new selective β-blocking agent, on ventricular rate in patients with longstanding AF has been studied. A decrease in the mean ventricular rate during rest and during exercise at various work loads was observed after both doses. The effect was more pronounced at the highest work load of 80 W, both after 50 mg (p < 0.002) and after 50 + 50 mg (p < 0.01) of the drug. A high initial heart rate at rest or during exercise was reduced more by the drug than a lower one. Exercise tolerance was reduced in 2 patients. These results suggest that patients with AF in whom satisfactory control of heart rate cannot be achieved with digitalis alone may benefit from addition of individualized metoprolol therapy.     

慢性心房颤动伴晕厥患者心电图回顾性分析

目的 回顾性分析19例慢性心房颤动（房颤）伴晕厥患者的心电图及动态心电图资料，探讨心电图特点，以及与临床转归的重要关系。方法 分析两年来入组患者的心电资料及晕厥发作时的相关心电图。结果 全组19例患者，16例晕厥系房颤伴缓慢心室率引起，平时就有房颤伴二度房室阻滞的心电图表现；2例晕厥为突发室颤所致；1例晕厥原因不明。心率缓慢组脑梗死的发生率明显增多。结论 本文资料显示，房颤伴心室率缓慢的患者有较高的晕厥及脑梗死的发生危险，房颤是室颤发生的重要原因之一，提示房颤不是一种良性心律失常。     

以动态心电图心室率参数指导心房颤动伴长R-R间距者活动时心室率的控制

目的探讨心房颤动(Af)伴长R-R间距活动时的心室率控制情况。方法回顾分析92例住院者的动态心电图(DCG)检查结果,其中:①Af伴长R-R间距62例(A组);②窦性心律、偶发房性早搏及室性早搏30例(B组)。观察两组的心室率分布情况。将A组患者在强心、利尿、抗凝的药物治疗基础上随机分为:常规组(A1组)30例,倍他乐克25毫克2/日;非常规组(A2组)32例,倍他乐克50毫克1/日。采用最高、最低、平均心室率、24h总心室率、每小时平均心率等参数,分析Af伴长R-R间距的心室率控制情况。结果 A组最高心率、平均心率、24h总心率均快于B组,差别有统计学意义(P<0.05,P<0.001)。A组最低心率慢于B组最低心率,差别有统计学意义(P<0.001)。通过适当增加晨起给药量倍他乐克50毫克1/日能达到更好的运动时心室率的控制。患者的最高心率、平均心率、24h总心率均慢于A1组,差别有统计学意义(P<0.05,P<0.001)。其最低心率与B组差别无统计学意义(P>0.05)。结论采用24h DCG对心室率等各项参数进行观察,为临床治疗和疗效的判断提供依据。提示在心室率高峰前用药,即合理增加晨起给药量,可达...     

普罗帕酮与洋地黄转复慢性心房颤动的比较

目的 比较普罗帕酮与洋地黄转复慢性房颤的作用。方法 房颤发作时间大于3周的患者随机分为普罗帕酮组和洋地黄组,普罗帕酮组先静脉推注普罗帕酮2mg/kg,再以5mg/kg维持24小时,后改口服每天450mg治疗4周。洋地黄组先静脉推注毛花甙C 0.4mg,然后每6小时静脉推注0．2mg,24小时后改口服地高辛每日0．25mg。结果 普罗帕酮组17例（48．6％）转复为窦性心律,洋地黄组仅2例转复成功。普罗帕酮组转复成功者与未转复者相比,左房内径明显较小（P＜0．001）,房颤持续时间显著较短（P＜0．001）。结论 普罗帕酮可有效地用于慢性房颤的转复,洋地黄转复慢性房颤疗效不佳;左房内径、房颤持续时间是影响转复成功的重要因素。     

动态心电图对阵发性心房颤动心电触发机制的分析

目的探讨阵发性心房颤动(PAf)心电触发因素及其部位,并评价其临床意义。方法对45例PAf患者的动态心电图人工回放,记录心房颤动(Af)发作次数、发作时间、发作前三个心房周期、联律间期,并根据触发Af的房性期前收缩的P波形态确定房性期前收缩部位。结果45例PAf患者共248次Af发作,心电触发因素中房性期前收缩占84.97%,窦性心动过缓占7.73%,心房扑动占2.14%,房性心动过速占2.57%;房性期前收缩来源于左心房上部占69.96%,左心房下部占12.02%,右心房上部占9.87%,右心房下部占3.86%;触发Af的房性期前收缩比未触发Af的房性期前收缩的联律间期缩短25ms以上;PAf发作存在23:00~1:00及9:00~11:00两个高峰,13:00~15:00一个低谷;PAf大多在短-长-短周期后发作,占62.23%,长-长-短周期后发作占21.89%。结论左心房上部房性期前收缩是PAf主要的触发因素,长-短周期现象是PAf发作的重要启动机制,自主神经失衡在PAf发作中起协同作用。动态心电图能对PAf治疗提供很大帮助。     

洋地黄治疗心力衰竭伴心房颤动时出现长R—R间期的临床意义

46例慢性心衰房颤患者,使用洋地黄治疗时心电图上R-R间期达1.5秒以上或见1秒以上的等长R-R。其中30例继续用维持量地高辛口服,28例并未发生洋地黄中毒的表现。提示上述心电图改变多数不是停用洋地黄的指征。     

立体心电图分析阵发性房颤患者心房的电生理特性

目的应用立体心电图(three-dimensional electrocardiogram,3D-ECG)分析阵发性房颤患者心房传导时间、心房除极角度和振幅的变化。方法入选在住院的阵发性房颤患者13例,对照组患者15例。分别应用立体心电图仪记录窦律下的立体心电图,分析后比较两组患者心房传导时间,P波除极振幅及角度。同时记录患者入院时超声心动图中左心房内径数值进行比较。结果两组患者比较左心房内径无显著差异。阵发性房颤组与对照组心房传导时间分别为123.75±11.67msvs.111.39±13.52ms,两组比较有显著性差异(p<0.05)。而在心房除极角度、振幅上,两组无显著差异。与对照组比较,阵发性房颤组患者P环初始部的运行方向与泪点疏密程度无明显变化,但在P环中间至终末部分,P环运行方向及泪点疏密出现明显变化,并且可看到明显的曲折、弯曲。但在除极末20ms的振幅,房颤患者较对照组明显降低(0.05±0.013mvvs.0.036±0.014mv,p<0.05),除极末30ms、40ms处两组振幅无显著差异。结论阵发性房颤患者可以出现心房传导时间延长、心房除极末振幅的改变和立体三维P环运行方向及泪点疏密程...     

Value of the atrial signal-averaged electrocardiogram in identifying patients with paroxysmal atrial fibrillation

Atrial signal-averaged electrocardiogram was compared between 25 patients with paroxysmal atrial fibrillation and 20 healthy persons without atrial arrythmias (control). The duration time of the high frequency (50–250 Hz) P wave was significantly (P < 0.01) prolonged in the groups of patients with paroxysmal atrial fibrillation compared with the control group (116 ± 16.4 versus 92 ± 8.1 msec). The diagnostic value of the duration of the high frequency P wave for identifying patients with paroxysmal atrial fibrillation was 104 msec. Using this criterion, a sensitivity of 76% and a specificity of 90% were achieved. Our observation has shown that the atrial signal-averaged electrocardiogram is a useful technique for identifying patients with paroxysmal atrial fibrillation.     

心房颤动患者心房活动特征的提取与分析

目的构造一种新的盲源分离方法，从心房颤动（简称房颤）患者心电图中有效提取心房活动信号，在此基础上分析心房活动的特征指标。方法采用小波变换来实现心电信号的稀疏表示，证明了独立分量分析（ICA）的3个基本条件在小波域依然满足，建立了小波域心电信号的独立分量分析的数学模型。结果应用小波域独立分量分析模型可以有效提取心房活动信号。讨论了与房颤相关的P波离散度、频谱、房颤周长等几个预测指标的具体实现，比较了不同房颤的具体特征。结论该算法可以有效提取房颤特征信号，对房颤机制的深入研究以及临床治疗具有很好的借鉴意义。     

心房颤动患者心房活动特征的提取与分析

目的构造一种新的盲源分离方法,从心房颤动(简称房颤)患者心电图中有效提取心房活动信号,在此基础上分析心房活动的特征指标。方法采用小波变换来实现心电信号的稀疏表示,证明了独立分量分析(ICA)的3个基本条件在小波域依然满足,建立了小波域心电信号的独立分量分析的数学模型。结果应用小波域独立分量分析模型可以有效提取心房活动信号。讨论了与房颤相关的P波离散度、频谱、房颤周长等几个预测指标的具体实现,比较了不同房颤的具体特征。结论该算法可以有效提取房颤特征信号,对房颤机制的深入研究以及临床治疗具有很好的借鉴意义。     

阵发性心房颤动的动态心电图分析

目的探讨动态心电图对阵发性心房颤动诊断和疗效判断的意义。方法分析78例阵发性心房颤动患者和80例对照组的24h动态心电图。统计单个期前收缩总数、心房颤动的频率和持续时间、心房颤动相关的偶联间期、非心房颤动患者房性期前收缩的偶联间期及24h房性期前收缩总数。结果心房颤动组:共发作33314阵心房颤动,其中36例11173阵发生在8∶00至22∶00,74例22141阵发生在22∶00至8∶00。平均24h房性期前收缩8242±1245个,心房颤动456±122阵。诱发心房颤动的,17例为单一房性期前收缩的偶联间期,33例为两种房性期前收缩的偶联间期,28例为两种以上房性期前收缩的偶联间期。发作前与发作相关的房性期前收缩偶联间期为0.429±0.089s,54例房性期前收缩伴心室内差异性传导,平均心率175±41次/min,64例6284阵心房颤动时伴有心悸、胸闷等症状,而69例27026阵发作时前无明显症状。对照组无心房颤动发生,35例有短阵房性心动过速,24例有频发房性期前收缩,56例有偶发房性期前收缩,房性期前收缩偶联间期0.633±0.014s,明显长于心房颤动组发作前与心房颤动相关的房性期前收缩及未下传的房性期前收缩偶联间期(P<0.01)。结论动态心电图监测是阵发性心房颤动诊断和疗效评价方面可靠、高效、重复性好的检查手段。     

An electrocardiogram marker to detect paroxysmal atrial fibrillation

An electrocardiogram marker to detect patients who have paroxysmal atrial fibrillation (PAF) is reported. The data set of ECG records made available by PhysioNet for Cardiology Challenge 2001 was used. The method uses a filtered time series with a frequency range between 3 and 9 Hz obtained from the electrocardiogram record. Typically, frequencies observed when a patient is in atrial fibrillation and atrial flutter is within this frequency range. Filtering was done using wavelets. Thereafter, the temporal properties of this filtered time series are studied. The temporal properties studied are the standard deviation, standard deviation of successive differences, and the length of the ellipse in the Poincare plot. The results indicate that these temporal properties of patients with PAF are depressed compared to the healthy group. A marker based on these temporal properties shows promise in detecting PAF when patients are in normal sinus rhythm. Results also show that the values for these temporal properties for a patient with PAF show little variation with time, and its measure is not dependent on the time of occurrence of a PAF episode.     

Right atrial appendage function in patients with chronic nonvalvular atrial fibrillation

To assess right atrial appendage (RAA) flow and its possible relationship to left atrial appendage (LAA) flow in chronic nonvalvular atrial fibrillation (AF), transesophageal echocardiography (TEE) was performed in 26 patients with chronic nonvalvular AF (group I). For the purpose of comparison, an additional group of 27 patients with chronic valvular AF due to mitral stenosis (group II) was analyzed. The clinically estimated duration of AF in group I was significantly longer than that of group II (8.7+/-3.4 versus 2.7+/-1.1 years). Although right atrial size and RAA maximal area were larger in group I than those in group II, left atrial size was larger in group II than that in group I. Group II had larger LAA maximal areas than group I, but this difference did not reach statistical significance. The two groups were not different with respect to the RAA or LAA emptying velocities. Significant correlations were observed between echocardiographic parameters of the two atria in patients with nonvalvular AF (r range, 0.4 to 0.7). In contrast, in patients with valvular AF, no correlation was observed between the echocardiographic parameters of the two atria (appendage emptying velocity, r = 0.38, p = 0.051; atrial size, r = -0.03, p = 0.89; maximal appendage area, r = 0.07, p = 0.75, respectively). There were no significant differences in the presence of right and left atrial spontaneous echo contrast and thrombus between the groups. All of the right and left atrial thrombi were confined to their respective appendages and were found in the atria with spontaneous echo contrast. Both RAA and LAA thrombi were present in one patient. In conclusion, our findings suggest that AF could affect both atria equally in nonvalvular AF, in contrast to valvular AF. Therefore, the assessment of RAA function as well as LAA may be important in patients with chronic nonvalvular AF.     

动态心电图评价房性早搏诱发阵发性心房颤动的研究

目的用24h动态心电图观察房性早搏所诱发的房颤,探讨其发生的机制及与长短周期现象的关系。方法对100例常规心电图检查发现有房性早搏的患者进行动态心电图监测,观察房性早搏诱发房颤时的长短周期时间及特点。结果100例房性早搏患者动态心电图监测出现阵发性房颤21例(21.0%)、短阵房速26例(26.0%),动态心电图监测发现阵发性房颤100%由房性早搏诱发。结论通过动态心电图监测发现房性早搏患者房颤发生率较高,加强对房性早搏的认识,减少房颤的发生。     

Alterations in atrial electrophysiology associated with chronic atrial fibrillation in man.

BACKGROUND: The purpose of this study was to determine the changes in atrial electrophysiology associated with chronic persistent atrial fibrillation in man. METHODS AND RESULTS: Atrial monophasic action potential duration at 90% repolarization and the effective refractory period were measured in 13 patients with chronic persistent atrial fibrillation after low-energy endocardial cardioversion, and compared to eight controls without a history of atrial fibrillation. Measurements were made at the right atrial appendage and midlateral right atrial wall at basic, 600 ms and 400 ms drive cycle lengths. In control patients, the effective refractory periods were significantly longer at the atrial appendage than the lateral wall at 600 ms (right atrial appendage 265 ms, midlateral right atrial wall 228 ms, P<0.05), and 400 ms cycle lengths (right atrial appendage 270 ms, midlateral right atrial wall 218 ms, P<0.05), but this was not evident in patients with atrial fibrillation. The monophasic action potentials and effective refractory periods at both atrial sites were shorter in the atrial fibrillation patients compared to controls; however, only the effective refractory periods at atrial appendage at 600 ms (atrial fibrillation 210 ms, controls 265 ms, P<0.001), and 400 ms cycle lengths (atrial fibrillation 200 ms, controls 270 ms, P>0.001) reached statistical significance. Effective refractory period dispersion was significantly greater in controls than in patients with atrial fibrillation (cycle length 600 ms: controls 36, atrial fibrillation 13, P=0.01; cycle length 400 ms: controls 54, atrial fibrillation 18, P<0.01). CONCLUSIONS: In patients without a history of atrial fibrillation, the refractory period at the right atrial appendage is significantly longer than at the midlateral right atrial wall. This 'normal' pattern of atrial refractory dispersion is lost in patients with chronic persistent atrial fibrillation, with marked shortening of the effective refractory period at the right atrial appendage. This may explain the high risk of recurrence of atrial fibrillation following successful electrical cardioversion.