Echocardiography in Patients With Constrictive Pericarditis Before and After Pericardiectomy

Fifteen patients with constrictive pericarditis were prospectively evaluated with echocardiography and Doppler recordings during respiratory monitoring. Eleven who agreed to surgery also underwent right heart catheterization and a repeat echocardiography with Doppler 10 days after pericardiectomy. Preoperatively, there was a significant inspiratory decrease in the mitral E wave (P < 0.05) and increase in the tricuspid E wave velocities (P < 0.05), which both normalized after pericardiectomy. The mitral deceleration times increased from 110 +/- 40 to 149 +/- 46 msec (P < 0.05) postoperatively. The preoperative hepatic vein velocities showed an accentuated systolic flow pattern. The systolic to diastolic ratio of the hepatic vein velocities was higher in patients who improved with surgery (1.42 +/- 0.31 vs 0.65 +/- 0.13) (P < 0.05). Postoperatively the diastolic flow became more pronounced. There was a 100% expiratory diastolic flow reversal in eight patients preoperatively, which normalized after pericardiectomy. Clinically these patients improved significantly postoperatively. Left atrial size, ejection fraction, and mitral and tricuspid filling velocities during respiratory monitoring could not predict surgical outcome. Pericardiectomy improved Doppler filling dynamics in all patients although this was not parallel to clinical improvement.     

Maintenance of Sinus Rhythm after Cardioversion of Atrial Fibrillation in Patients with Lone Atrial Fibrillation and Patients with Hypertension

Background: The success rate and prognosis of cardioversion of atrial fibrillation (AF) in patients with organic heart disease is well known. In contrast, little data exist about cardioversion success and maintenance of sinus rhythm (SR) in patients with lone AF and in patients with hypertension as the only underlying cardiovascular disease. Methods: In a prospective cardioversion registry 148 of 181 patients (81.8%) with lone AF (age 58 ± 13 years, duration of AF 7.6 ± 19 weeks) and 120 of 148 patients (81.1%) with hypertension (age 62 ± 10 years, duration of AF 6.6 ± 21 weeks) had successful cardioversion and were followed for 7.7 ± 1.9 months. Results: At follow-up, 120 patients (81.1%) with lone AF were in SR, and 18 of these patients had had repeated cardioversion during follow-up (AF total recurrence rate 31.1%). In stepwise regression analysis, the number of previous cardioversions was predictive of rhythm at follow-up (P = 0.0453). Rhythm at follow-up did not differ between patients who were or were not on antiarrhythmic drugs. At follow-up 96 patients (80%) with hypertension were in SR, and 9 of these had had repeated cardioversion during follow-up (AF total recurrence rate 27.5%). As in lone AF, the recurrence rate of AF did not differ between patients with or without antiarrhythmic drug treatment, and in multivariate regression analysis, the number of previous cardioversions was the only clinical predictor of rhythm at follow-up (P = 0.0284). Conclusions: Even in patients with such benign conditions as lone AF or hypertension as the only underlying disease, the prognosis of cardioversion in terms of maintenance of SR is poor. Future studies of rhythm control versus rate control need to include not only patients with organic heart disease but also patients with lone AF and patients with hypertension, since the long-term benefits of these two strategies remain unclear even in these subsets of patients.     

心包腔内注射尿激酶对实验性缩窄性心包炎的防治作用

将刺激合剂注入犬心包腔内使其形成实验性渗出性心包炎,然后分别将尿激酶(UK,4×10000U,治疗组,n=10)和生理盐水(对照组,n=11)注入犬心包腔内.结果,治疗组中UK能显著地降低心包渗出液中纤维蛋白原(Fib)含量(1.91±0.9vs2.6±1.11g/l,P<0.05).病理检查证实,对照组的11只犬全部形成了缩窄性心包炎,治疗组中仅有2只犬发生了心包粘连,两组粘连的发生率有非常显著的差异(20%vs100%、P<0.005).治疗组心包壁层的厚度显著地低于对照组(0.38±0.06vs0.66±0.10mm,P<0.001).用药期间血液中Fib水平(4.51±1.40vs3.85±0.78g/l)、白陶土部分凝血活酶时间(34.81±3.98vs36.40±5.10秒)和凝血酶时间(1.75±1.49vs16.31±1.10秒)均无显著变化(P>0.05).以上结果提示,UK可通过增强心包腔内局部的纤溶活性而防止心包粘连的形成.     

Constrictive Pericarditis with Cardiac Ascites Caused Spontaneous Bacterial Peritonitis

Patients with constrictive pericarditis (CP) typically present with symptoms related to right-sided heart failure, such as cardiac ascites. Spontaneous bacterial peritonitis (SBP) usually arises in association with ascites secondary to hepatic cirrhosis. We herein report a rare case of CP in which SBP developed due to cardiac ascites, even in the absence of cirrhosis. In this case, pericardiectomy improved both the hemodynamics and the ascites, while therapy with diuretics alone was insufficient. It is important to consider SBP in the differential diagnosis when any abdominal symptoms or an inflammatory response is found in patients with heart failure and cardiac ascites.     

Persistent Atrial Flutter in Patients Treated for Atrial Fibrillation with Amiodarone and Propafenone:

INTRODUCTION: Antiarrhythmic drugs have been reported to promote the conversion of atrial fibrillation to atrial flutter in patients with paroxysmal atrial fibrillation. However, information about the electrophysiologic mechanism and response to radiofrequency ablation of these drug-induced atrial flutters is limited. Furthermore, the determinants of the development of persistent atrial flutter in patients treated for atrial fibrillation with antiarrhythmic drugs are still unknown. METHODS AND RESULTS: Among the 136 patients treated for atrial fibrillation with amiodarone (n = 96) or propafenone (n = 40), 15 (11%, mean age 65.5 +/- 12.3 years) were identified to have subsequent development of persistent atrial flutter based on surface ECG characteristics during antiarrhythmic drug treatment. The mean interval between the beginning of drug treatment and the onset of atrial flutter was 5.0 +/- 5.5 months. Intracardiac mapping and entrainment studies revealed that 11 patients had counterclockwise typical atrial flutter, and 4 had clockwise typical atrial flutter. All 15 patients underwent successful ablation with creation of complete bidirectional isthmus conduction block. After a mean follow-up of 12.3 +/- 4.2 months, 14 (93%) of 15 patients who underwent successful ablation and continued taking antiarrhythmic drugs have remained in sinus rhythm. Univariate analysis of clinical variables demonstrated that only atrial enlargement was significantly related to the occurrence of persistent atrial flutter. CONCLUSION: In patients with atrial fibrillation, persistent typical atrial flutter might occur during antiarrhythmic drug treatment, and atrial enlargement was a risk factor for the development of such an arrhythmia. Radiofrequency ablation and continuation of pharmacologic therapy offered a safe and effective means of achieving and maintaining sinus rhythm.     

心房颤动患者的抗凝治疗

心房颤动是临床实践中最常见且危害严重的心律失常,是缺血性脑卒中的最主要危险因素之一。有效的抗凝治疗可显著降低心房颤动患者缺血性脑卒中的发生率,成为心房颤动患者治疗策略的重中之重。新型口服抗凝剂为心房颤动患者的抗凝治疗提供了更多选择。现结合近年发表的相关文献对心房颤动患者的抗凝治疗进行综述。     

超声心动图技术评价心房颤动患者左房功能的应用

左房功能对于维持左室功能有重要意义,超声心动图技术是评价心房颤动患者左房功能最常用的方法,现就近年来常用的关于评价左房功能的各种超声指标进行总结。     

Evaluation of Atrial Refractoriness and Atrial Fibrillation Inducibility Immediately after Internal Cardioversion in Patients with Chronic Persistent Atrial Fibrillation

Summary. Objective: To prospectively evaluate right atrial refractoriness and sustained atrial fibrillation (AF) inducibility at programmed electrical stimulation in two groups of patient: a series of patients with chronic persistent AF, studied immediately after successful low energy internal atrial cardioversion, and a group of control patients without history of supraventricular arrhythmias.Patients: Nineteen patients with chronic persistent AF (mean AF duration 11 ± 10 months, range 2–61 months) submitted to successful internal low energy atrial cardioversion in fully conscious state and 11 control patients without history of supraventricular arrhythmias.Methods: An electrophysiological evaluation was performed to measure atrial refractoriness and AF inducibility, by delivering single atrial extrastimuli in high right atrium, at decremental coupling, during spontaneous sinus rhythm and after 8 beats at 600, 500, 400 and 330 ms cycle length. If sustained AF was induced the protocol was terminated.Results: During programmed atrial stimulation sustained AF was induced in 8 out 19 (42%) of the AF patients but in none of the control group. Atrial effective refractory period was significantly shorter in AF patients compared to controls both at basic cycle length, at 600 ms, 500 ms and 400 ms cycle length, meanwhile no statistically significant differences were found at 330 ms cycle length. An altered relationship between atrial effective refractory period and cycle length was found in AF patients compared to controls: the slope of linear correlation slope was significantly lower in AF group than in controls (0.04 ± 0.07 vs 0.17 ± 0.10, p < 0.002).Conclusions: Marked abnormalities of atrial refractoriness and of its heart rate relationship are observed after internal cardioversion of chronic persistent AF in humans and these abnormalities are associated with an high vulnerability to AF. These observations may explain the high risk of AF recurrences in the early phases following successful cardioversion. In this scenario antiarrhythmic drug therapy seems to be mandatory for reducing arrhythmia relapses.     

D-二聚体在心房颤动病人血浆中含量变化及临床意义分析

目的观察心房颤动(房颤)病人血浆D-二聚体(D-dimer)水平的变化,并探讨其意义.方法应用免疫比浊法测定63例房颤病人(其中风心病22例,冠心病41例)和20例正常人血浆D-二聚体.结果房颤病人与正常人相比,房颤病人血浆D-dimer浓度为(252.2～456.6)mg/L,显著高于正常人(102.6～389.8)mg/L(P<0.01);风心病病人D-dimer浓度(262.0～446.5)mg/L与冠心病病人D-dimer浓度(252.2～456.6)mg/L比较,无统计学意义.结论房颤病人血浆D-dimer水平升高,与其高发血栓栓塞并发症有关,通过检测血中D-二聚体水平的改变,有助于了解房颤发生血栓栓塞的危险程度.     

心房颤动导管消融术后快速性房性心律失常的机制和治疗

随着心房颤动导管消融治疗的日益广泛开展,导管消融术后快速性房性心律失常（即继发性房性心律失常,包括房性心动过速和心房扑动）逐渐成为临床心律失常治疗的关注热点,其机制在不同患者中不尽相同,甚至同一患者亦可涉及多种机制,因此这种心律失常的处理可能较心房颤动本身更为棘手。现就心房颤动导管消融术后发生快速性房性心律失常的可能机制及其防治策略作一综述。     

Electrophysiologic Characteristics of Complex Fractionated Atrial Electrograms in Patients with Atrial Fibrillation

Introduction: The underlying mechanisms of complex fractionated atrial electrogram (CFAE) during radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) have not yet been clearly elucidated. We explored the relationships between CFAE and left atrial (LA) voltage, or conduction velocity (CV).
Methods and Results: In 50 patients with AF (23 paroxysmal AF [PAF], 41 males, mean age 55.76 ± 10.16 years), the CFAE (average index of fractionation of electrograms during AF by interval-analysis algorithm, cycle length [CL]≤ 120 ms) areas, voltage, and CV were measured at eight different quadrants in each patient's LA by analyzing a NavX-guided, color-coded CFAE CL map, a voltage map, and an isochronal map (500 ms pacing) generated by contact bipolar electrograms (70–100 points in the LA). The results were: (1) CFAE areas were predominantly located in the septum, roof, and LA appendage; (2) CFAE area had lower voltage than those in non-CFAE area and was surrounded by the areas of high voltage (P < 0.0001); (3) The CFAE areas had low CVs compared with non-CFAE areas (P < 0.001); and (4) The percentage of CFAE area was lower in patients with persistent atrial fibrillation (PeAF) compared with those with PAF (P < 0.05).
Conclusions: The CFAE area, which is primarily located at the septum, has a low voltage with a lower CV, and is surrounded by high-voltage areas. Underlying electroanatomical complexity is associated with clustering of CFAEs.     

Atrial Pacing Therapies for Prevention of Atrial Fibrillation in Patients with Implantable Defibrillators

Atrial fibrillation (AF), atrial flutter and atrial tachycardia (AT) occur frequently in patients following implantation of an implantable cardioverter defibrillator (ICD) for the treatment of ventricular tachyarrhythmias. Some new generation ICDs have incorporated atrial antitachycardia pacing therapy (ATP) and atrial pacing algorithms designed specifically for the prevention of AF. In the GEM III AT clinical evaluation, atrial ATP efficacy for termination of AF and AT was assessed. Overall ATP efficacy for AF/AT, based on device classification, was 40% when adjusted using the Generalized Estimating Equations to account for correlated data that arises from utilizing multiple episodes in some patients. However, many episodes of AF/AT were noted to terminate within 10 minutes of onset. Applying a more conservative definition of efficacy, termination within 20 sec of delivery of the last atrial ATP, efficacy for termination of AF/AT was 26%. 50 Hz burst pacing was shown to have minimal efficacy for termination of AF and modest incremental benefit following ramp or burst pacing therapies for AT. These observations provide a more realistic expectation of the value of atrial ATP in the ICD population with AF. Atrial ATP terminates some episodes of AT but previously reported efficacy rates of 40-50% are exaggerated and in part reflect spontaneous terminations of some AF/AT episodes.     

Radiofrequency Modification of the Atrioventricular Node in Patients with Chronic Atrial Fibrillation:

RF Modification of AVN in AF. Introduction : We compared, in a prospective and randomized fashion with a cross-over design, the anterior and posterior approaches to radiofrequency (RF) modification of the AV node in patients with chronic atrial fibrillation.
Methods and Results : Thirty-three patients were randomized to receive first an anterior (group I) or posterior (group II) approach for RF modification of AV nodal conduction. Patients who did not fill the endpoint ventricular rate (< 90 beats/min) were crossed over to the alternative approach. After the anterior approach in group I patients, mean ventricular rate was significantly lower than in group II patients after the posterior approach (79.6 ± 18.8 beats/min vs 110.8 ± 16.2 beats/min, P < 0.001). In group I, 14 (82%) of 17 patients fulfilled the endpoint, 1 (6%) had complete AV block, and 2 (12%) were crossed over to the posterior approach fulfilling the endpoint. In group II, 4 (25%) of 16 patients fulfilled the endpoint. No transient or permanent high-degree AV block was observed. Among the 12 patients who were crossed over to the anterior approach, 8 fulfilled the endpoint, whereas 4 had permanent high-degree AV block. RF ablation carried out only in the anterior region was safer than a stepwise approach (6% vs 33% incidence of AV block), even though the difference did not reach statistical significance (P = 0.09).
Conclusion : Posterior AV nodal modification is less effective but safer than anterior AV nodal modification. However, to reduce the incidence of AV block, the anterior approach is preferable to a stepwise approach from the posterior to the anterior zone.     

Electrophysiologic Characteristics of a Dilated Atrium in Patients with Paroxysmal Atrial Fibrillation and Atrial Flutter

This study investigated the difference of atrial electrophysiologic characteristics between a normal and dilated atrium and compared them among patients with paroxysmal atrial fibrillation and flutter. Twenty-seven patients with paroxysmal atrial fibrillation and 28 patients with paroxysmal atrial flutter were divided into four subgroups, according to the presence of a normal atrium or bilateral atrial enlargement. Thirty patients without atrial arrhythmia (20 patients with normal atrium and 10 patients with bilateral atrial enlargement) were included in control group. The atrial refractoriness in patients with a dilated atrium was longer than those with normal atrial size. In patients with paroxysmal atrial fibrillation and patients of control group, the P-wave duration and interatrial conduction velocity with or without atrial enlargement were similar. However, in patients with paroxysmal atrial flutter, P-A_PCS (86 ± 10 ms vs. 73 ± 9 ms, p < 0.05) and P-A_DCS (109 ± 9 ms vs. 95 ± 9 ms, p < 0.05) in patients with a dilated atrium were longer than in patients with a normal atrium. The patients with paroxysmal atrial fibrillation or atrial flutter all demonstrated longer P-wave duration and interatrial conduction time than control group. Among the groups with a normal atrium or a dilated atrium, atrial refractoriness in patients with paroxysmal atrial flutter was shorter than that in control group. Moreover, in the patients with a normal atrium, the potential minimal wavelength in control group (6.6 ± 1.7) was longer than that of paroxysmal atrial fibrillation (5.3 ± 1.1), or atrial flutter (5.0 ± 1.2). These findings suggest that atrial electrophysiologic characteristics of a dilated atrium were different from those of normal atrium, and these changes were different between paroxysmal atrial fibrillation and flutter. Multiple factors are considered to be related to the genesis of atrial tachyarrhythmias.     

心房重构的机制及临床意义

心房颤动时心房一方面发生电重构,主要表现为L型钙离子通道功能下降和心房的不应期缩短;另一方面出现组织结构重构,主要表现为细胞间质的纤维化、心房的淀粉样变性。针对心房重构的一些药物在临床应用并取得一定疗效,为心房颤动的治疗提供了新的思路。     

Constrictive pericarditis: Its history and current status

The diagnosis of constrictive pericarditis remains a challenge because it is often mimicked by restrictive cardiomyopathy. The last few years have seen numerous advances in our ability to differentiate between these two conditions which often have similar physical findings and hemodynamics. This review begins with a brief history of constrictive pericarditis; this is followed by an extensive discussion of newer etiologies, and then the classical clinical history and physical examination findings are described. Radiologic, electrocardiographic, and angiographic findings are discussed. The hemodynamics of constrictive pericarditis are reviewed. Recent results of echocardiographic and echo-Doppler investigations are presented. Emphasis is placed upon the limitations of M-mode echocardiography in the diagnosis of constrictive pericarditis. The value of echocardiographic Doppler studies of mitral and tricuspid flow velocity patterns, as well as of those in the pulmonary veins and hepatic veins, is described. Nuclear ventriculograms and angiocardiograms tend to show more rapid ventricular filling in constrictive pericarditis than in restrictive cardiomyopathy. Although only a small number of patients has been studied, these evaluations seem to have merit in separating restrictive cardiomyopathy from constrictive pericarditis. The role of computed tomography scanning and magnetic resonance imaging studies of pericardial thickness in confirming the presence of constrictive pericarditis is discussed. Abnormal pericardial thickening (> 3 mm) confirms the diagnosis of constrictive pericarditis, but only if the characteristic hemodynamic pattern is present. The usefulness of endomyocardial biopsy in recognizing specific varieties of restrictive cardiomyopathy is presented. The topic of occult constrictive pericardial disease is discussed briefly. A discussion of the timing of pericardial resection for the treatment of constrictive pericarditis ends the review.     

Localization of Left Atrial Ganglionated Plexi in Patients with Atrial Fibrillation

Background. The intrinsic cardiac autonomic nervous system (ICANS), which forms a neural network, has been shown to be a critical element responsible for the initiation and maintenance of atrial fibrillation (AF). We developed a technique to localize and ablate the ganglionated plexi (GP), which serves as the "integration centers" of the ICANS.
Method. The four major atrial GP are localized by delivering high frequency stimulation (HFS; 20 Hz, 10–150 V, 1–10 ms pulse width) to atrial tissue where GP are presumed to be located. Sites showing a parasympathetic response, which is arbitrarily defined as ≥50% increase in mean R-R interval during AF, was assigned as a GP site. Radiofrequency current is then applied to that site to eliminate the parasympathetic response. All patients received ablation of the four major atrial GP, followed by pulmonary vein antrum ablation.
Results. Our preliminary results showed that all the four major atrial GP can be identified in the vast majority of patients. The parasympathetic response can be eliminated by applying radiofrequency current. In the first 83 patients, the percent of patients free of symptomatic AF or atrial tachycardia after a single ablation procedure was 80% at 12 months and 86% at a mean follow-up of 22 months.
Conclusion. These results indicate additional benefits of GP ablation to PV antrum ablation and improvement with time, particularly ≥ 12 months after ablation. We postulate that this late benefit may result from destruction of the autonomic neurons in the GP that cannot regenerate.