The alternation between atrial flutter and atrial fibrillation.

Atrial fibrillation and atrial flutter share a common reentrant mechanism. However, the relationship between these arrhythmias has not been systemically studied to date. To evaluate the degree to which these arrhythmias may alternate, consecutive Holter monitor recordings which showed fibrillation or flutter in 96 patients were reviewed. One half of the patients were studied after open-heart surgery and the other half for varying indications. One quarter of the patients had atrial flutter in addition to fibrillation, and this alternation with flutter was significantly associated with the use of a type 1A antiarrhythmic drug (p = 0.007), but not with the use of digoxin or beta blockers (p = NS for both). Furthermore, this alternation with flutter was more common in the postoperative group (p = 0.01). A history of embolization was less common in patients who were in the postoperative group (p = 0.003) and patients who had flutter in addition to fibrillation (p = 0.05).     

心房颤动合并冠心病的抗栓治疗

心房颤动(房颤)和冠状动脉性心脏病(冠心病)均为常见的心血管疾病,有着某些共同的危险因素,如糖尿病和原发性高血压.另外,冠心病中的某些临床情况,如心肌梗死和心力衰竭,亦是房颤的危险因素.……     

Coronary artery diseases in Japanese patients with nonvalvular atrial fibrillation

BackgroundBoth the prevalence of atrial fibrillation and coronary artery disease (CAD) is increasing in aged societies. However, limited data are available regarding the prevalence of CAD and the incidence of coronary events in Japanese patients with nonvalvular atrial fibrillation (NVAF).Methods and resultsThe data in this study were derived from Shinken Database 2004–2010, which includes 15,227 new patient visitors to the Cardiovascular Institute between June 2004 and March 2011. In the database, 1835 patients were diagnosed with NVAF (mean age 63 years, mean CHADS2 score 1.1 ± 1.1, and 75% were men). The prevalence of CAD at the initial visit was 118 patients (6.4%). They were older age and had a greater prevalence of men, more history of congestive heart failure and more history of cardiovascular risk factors rather than those without. During the follow-up period of 532 ± 599 days, coronary events (myocardial infarction, unstable angina, and stable angina) occurred in 51 patients (1.9%/year). Multivariate analysis showed that a history of CAD (p < 0.001) and older age (p = 0.024) were independent predictors of the incidence of future coronary events.ConclusionsIn Japanese patients with NVAF, both the presence of CAD and the occurrence of coronary events are not uncommon. History of CAD and older age are strongly associated with the incidence of coronary events.     

病毒性心肌炎心肌颗粒酶B表达的实验研究

目的 探讨颗粒酶B在柯萨奇病毒B组病毒介导的病毒性心肌炎心肌病变及发病机制中的作用.方法 将36只5周～6周龄雄性BALB/c小鼠随机分成两组:正常组10只,模型组26只.模型组以病毒液0.1 mL腹腔注射建立模型,正常组予0.1 mL不含病毒的Eagle's基本必需培养基液腹腔注射.于第11 d处死小鼠取出心脏,分别在肉眼下、光镜下和电镜下观察心肌的病变并计分;以半定量逆转录酶聚合酶链反应和免疫组化方法 检测心肌颗粒酶B的表达.结果 模型组心肌大体病变计分显著高于正常组,差异有统计学意义[(3.2±1.6)分 vs. (0.2±0.1)分,P<0.01].光镜下模型组心肌病理计分显著高于正常组,差异有统计学意义[(8.4±4.5)分vs. (0.3±0.1)分,P<0.01].电镜下模型组心肌细胞超微结构损害严重,正常组心肌细胞超微结构均正常.免疫组化显示模型组每高倍视野颗粒酶B阳性细胞数显著高于正常组,差异有统计学意义[(2.7±1.1)个 vs.(0.0±0.0)个,P<0.01].直线相关与回归分析表明,模型组小鼠心肌浸润细胞颗粒酶B阳性细胞数与心肌病理计分呈显著正相关(r=0.859,P<0.01).逆转录酶聚合酶链反应产物电泳条带的半定量分析表明,模型组心肌颗粒酶B扩增产物产量高,而正常组无颗粒酶B表达.结论 心肌浸润细胞中颗粒酶B的表达在病毒性心肌炎心肌损伤中起一定作用,其表达水平与心肌病理损害严重程度一致.     

Premature atrial beat eliciting atrial fibrillation after coronary artery bypass grafting

Of patients undergoing coronary artery bypass grafting 30% develop atrial fibrillation (AF) or flutter. To determine if AF is initiated from the right or left atrium, atrial electrograms were continuously recorded in patients undergoing this procedure. In addition, to study whether the prematurity index of premature atrial contractions (PACs) eliciting AF differs from PACs not provoking AF, the distribution of prematurity indices was evaluated from R-R interval analysis. The right and left atrial recording electrodes were first activated by the ectopic beat provoking AF in six and eight patients, respectively. The prematurity index of the PAC eliciting AF was located in the middle (in half of the patients) or to the left of the median distribution of prematurity indices. The variability in activation of the atrial electrodes suggests that the PAC provoking AF can have its origin in the right, the septal, or the left region of the atrium. The initiation of AF depends on the prematurity index of the PAC.     

Chronic atrial fibrillation and coronary artery disease.

Retrospective study of the incidence of atrial fibrillation (AF) in 841 consecutive patients who had selective coronary arteriography and left ventricular catheterization from January 1, 1966 to December 31, 1976 was undertaken. There were 496 patients with coronary artery disease (CAD), 138 with valvular disease or cardiomyopathy, and 207 were normal. Chronic atrial fibrillation was present in 45 patients, of whom 35 has valvular disease or cardiomyopathy. One had coronary artery disease and 9 were normal. Chronic atrial fibrillation in coronary artery disease was rarely found.     

Predictors of atrial fibrillation recurrence in patients with long-lasting atrial fibrillation

BACKGROUND:

Limited data are available on the predictors of atrial fibrillation (AF) recurrence in patients with chronic AF.

OBJECTIVES:

To evaluate potential clinical, echocardiographic and electrophysiological predictors of AF recurrence after internal cardioversion for long-lasting AF.

METHODS:

A total of 99 consecutive patients (63 men and 36 women, mean age 63.33±9.27 years) with long-standing AF (52.42±72.02 months) underwent internal cardioversion with a catheter that consisted of two defibrillating coils. Shocks were delivered according to a step-up protocol. Clinical follow-up and electrocardiographic recordings were performed on a monthly basis for a 12-month period or whenever patients experienced symptoms suggestive of recurrent AF.

RESULTS:

Ninety-three patients (93.94%) underwent a successful uncomplicated cardioversion, with a mean atrial defibrillation threshold of 10.69±6.76 J. Immediate reinitiation of AF was observed in 15 patients (15.78%) of whom a repeated cardioversion restored sinus rhythm in 13 cases. Early recurrence of AF (within one week) was observed in 12 of 93 patients (12.90%). At the end of the 12-month follow-up period, during which seven patients were lost, 42 of the 86 remaining patients (48.84%) were still in sinus rhythm. Multivariate regression analysis showed that left atrial diameter (OR 1.126, 95% CI 1.015 to 1.249; P=0.025) and mitral A wave velocity (OR 0.972, 95% CI 0.945 to 0.999; P=0.044) were significant and independent predictors of AF recurrence, whereas age, left ventricular ejection fraction and AF cycle length were not predictive of arrhythmia recurrence.

CONCLUSION:

The present study showed that the left atrial diameter and mitral A wave velocity are the only variables associated with AF recurrence after successful cardioversion.     

心房颤动合并冠心病患者的抗血栓治疗进展

心房颤动常与冠心病并存,需要联合抗凝和抗血小板治疗以减少卒中和心血管事件风险,但联合抗栓治疗增加出血风险,需权衡抗栓治疗的利弊。目前,尚缺乏大规模临床证据。本文对相关临床证据和国内外指南推荐进行综述。     

Acute myocardial infarction due to coronary artery embolus associated with atrial fibrillation

Abstract

Coronary artery embolus is a rare and potentially under- recognised cause of acute myocardial infarction. We describe the case of an 80-year-old woman presenting with an acute coronary syndrome secondary to coronary artery embolus associated with atrial fibrillation, which was successfully treated with the use of a thrombectomy aspiration catheter.     

Predictors of atrial fibrillation after coronary artery bypass surgery

OBJECTIVE: Atrial fibrillation is one of the most common arrhythmias associated with not only increased morbidity after coronary artery bypass grafting but also increased healthcare costs. Many factors are associated with atrial fibrillation onset after coronary artery bypass grafting. We prospectively examined which factors could predict atrial fibrillation after coronary artery bypass grafting. METHODS: Fifty-seven consecutive patients (37 men, mean age=60.2+/-12 years) with sinus rhythm before coronary artery bypass grafting are included the study. Clinical, demographic, laboratory and echocardiographic characteristics are all evaluated prospectively. The maximum and minimum P-wave duration (P(max) and P(min)) were measured from the 12-lead surface electrocardiogram. The difference between the P(max) and the P(min) was calculated and defined as P-wave dispersion. Preoperative venous blood samples were taken for N-terminal proBrain natriuretic peptide level analysis. RESULTS: Ten (17%) patients had postoperative atrial fibrillation. Patients with postoperative atrial fibrillation were older (69.4+/-6 versus 58.2+/-12 years, P=0.01), had lower ejection fraction (44.1+/-8.9% versus 54.3+/-9; P=0.002), higher proBrain natriuretic peptide levels (538+/-136 pg/ml versus 293+/-359 pg/ml; P=0.03), longer P(max) (142.2+/-13.7 ms versus 120.8+/-21.2 ms; P=0.006) and longer P-wave dispersion (55.0+/-8.2 ms versus 41.3+/-14.3 ms; P=0.008) compared with the patients without atrial fibrillation. Univariate analysis showed that increased age (P=0.01), lower ejection fraction (P=0.02), enlargement of left atrium (P=0.02), increased P(max) (P=0.006) and increased P-wave dispersion (P=0.008) and increased level of preoperative proBrain natriuretic peptide (P=0.03) were associated with postoperative atrial fibrillation. Positive correlation was seen between the age and level of proBrain natriuretic peptide (r=0.322 and P=0.015). In multivariate analysis, age (P=0.05), lower ejection fraction (P=0.03), left atrial enlargement (P=0.05), longer P(max) (P=0.01) and P-wave dispersion (P=0.01) were found to be independent predictors of postoperative atrial fibrillation. CONCLUSION: Age, poor left ventricular functions, P(max) and P-wave dispersion are found to be independent predictors of atrial fibrillation after coronary artery bypass grafting.     

Prediction of atrial fibrillation via atrial electromechanical interval after coronary artery bypass grafting

Objectives: We sought to analyze the value of measuring atrial electromechanical interval (AEMI) in predicting post coronary artery bypass grafting (CABG) atrial fibrillation (AF).Background: Atrial fibrillation is the most common arrhythmia after CABG with as many as 10–40%. Several predictors are associated with the development of AF after cardiac surgery.Methods: At least 30 patients; 18 males and 12 females (mean age 53 + 12 years) with ischemic heart disease diagnosed by coronary angiography and underwent CABG enrolled in the study. Pre-operative data were collected including laboratory, 12-lead ECG to measure P wave duration and P wave dispersion, trans-thoracic echocardiography to measure LV dimensions, ejection fraction, and LA volume. Pre-operative tissue Doppler imaging (TDI) was used to measure atrial electromechanical interval (AEMI) in milliseconds from the onset of P wave on the surface electrogram till the onset of atrial systole (Am).Results: Our patients were classified into two groups, group I with documented post CABG AF and group II with no AF. It was found that the mean value of AEMI in group I patients was significantly longer; 136 + 5.6 vs 93.7 + 19 ms in group II patients (P < 0.001). Using receiver operator characteristic (ROC) analysis, it was found that the cutoff value of AEMI as a predictor of post CABG AF was 120 ms which achieves 100% sensitivity and 99% specificity. It was found also significantly increased P wave duration and dispersion in group I patients compared to group II (97.7 ± 3 vs 94 ± 3.9 ms; P = 0.02 and 26 ± 4.7 vs 23 ± 4.7; P = 0.04, respectively).Conclusion: using AEMI as a predictor of post CABG AF is a valuable marker which carries high sensitivity and specificity.     

左心房容积与冠状动脉旁路移植术后心房颤动相关性的研究

目的:评价冠状动脉旁路移植术(CABG)前,二维超声心动图估测左心房容积指数(LAVI)与术后心房颤动发生的相关性。方法:入选北京同仁医院2010年1月至2012年6月期间,入院实施CABG术的冠心病患者106例进行前瞻性分析。将患者分为术后心房颤动组和术后未发生心房颤动组。采用多因素Logistic回归分析,评价术前通过二维超声心动图估测的LAVI值与术后心心房颤动动发生的相关性。结果:CABG术后发生心房颤动患者19例,术后心房颤动发生率为17.9%。术后心房颤动组的LAVI值显著高于术后未发生心房颤动组[(22.1±4.1)vs.(18.1±5.1)m L/m2,P=0.018]。多元logistic回归分析显示,年龄(OR=1.015,95%CI:1.017~1.0323,P=0.026)、高血压病史(OR=1.053,95%CI:1.019~1.087,P=0.009)、既往心房颤动病史(OR=2.273,95%CI:1.207~3.340,P=0.010)、LAV值(OR=1.784,95%CI:1.181~2.487,P=0.003)是CABG后心房颤动发生的独立危险因素。结论:CABG术前通过二维超声心动图估测的LAVI值是冠心病患者CABG术后心房颤动发生的独立危险因素,对于预测CABG术后心房颤动发生并进行危险分层具有一定参考价值。     

心房颤动总是"引发"心房颤动吗?

心房颤动(AF)是临床上常见的心律失常,心房重构和AF"引发"AF概念的提出是对AF病理生理机制研究的重大进展,但临床上有关AF的诸多问题并不能都用AF"引发"AF和单纯的心房电重构来解释,本文就AF"引发"AF这一问题结合有关文献作一综述.     

老年心房颤动患者的冠状动脉病变分析

目的观察老年患者心房颤动(房颤)的发生与冠心病的关系。方法根据我院1990年以来的尸检资料,选择75岁以上生前有房颤发作记录的76例患者作为房颤组,平均年龄(86.9±6.9)岁,临床均诊断有冠心病;选择与房颤组年龄相近、临床无房颤记录、经尸检病理证实为冠心病的85例患者作为冠心病组,比较两组患者冠状动脉的病变情况。结果房颤组中38例患者经病理证实有冠心病,心肌梗死发生率为39.5%,冠心病组心肌梗死发生率为62.4%,两组比较有统计学差异(P<0.01);房颤组与冠心病组心脏重量、左心室壁厚度分别为[(437.5±80.6)%(434.6±90.3)g,P>0.05;(1.42±0.33)%(1.42±0.38)cm,P>0.05];房颤组冠状动脉达Ⅲ级病变和Ⅳ级病变的血管数量(40 vs.99、27 vs.52,P<0.001)明显少于冠心病组。结论老年患者心房颤动的发生与冠心病之间不存在明确的因果关系。