A case of Lamin C gene-mutation with preserved systolic function and ventricular dysrrhythmia

Lamin A/C gene-related cardiomyopathy is associated with progressive heart failure and malignant arrhythmias. Current guidelines advise the use of implantable defibrillators to prevent arrhythmogenic sudden cardiac death only in situations where there is evidence of severe left ventricular dysfunction. We describe a case of a woman with genetically confirmed Lamin C deficiency with preserved left ventricular function in whom an implantable defibrillator was inserted and within a month of implantation was used to terminate symptomatic ventricular tachycardia.     

Adverse reactions during treatment with amiodarone hydrochloride

Amiodarone was administered to 80 patients with recurrent cardiac tachyarrhythmias previously resistant to drug treatment. Forty nine patients were treated for ventricular tachycardia or fibrillation and 31 for supra-ventricular arrhythmias. The mean (range six days to 51 months), permitting a total of 100 patient years of observation. Adverse reactions were observed in 69 patients. Severe side effects were encountered in 13: four patients developed interstitial pneumonitis, four patients developed incessant ventricular tachycardia, three patients taking amiodarone and digoxin sustained sinus node arrest with depression of escape foci, one patient developed hepatitis, and one patient developed hypercalcaemia with renal failure. Furthermore, a rise in the serum concentration of digoxin and potentiation of warfarin anticoagulation occurred in cases in which these agents were combined with amiodarone. Amiodarone was stopped in 14 patients because of side effects. Although amiodarone is effective in suppressing arrhythmias in most patients in whom extensive use of antiarrhythmic drugs has been unsuccessful, it is associated with diverse and serious toxicity. These observations suggest that at present the use of amiodarone should be reserved for patients with life threatening or seriously disabling arrhythmias in whom longer established drugs have been ineffective or are contraindicated.     

Tp-e间期，Tp-e/QT与ICD一级预防患者发生恶性室性心律失常的关系

目的：探讨心电图T波峰末间期（Tp-e）及T波峰末间期与QT间期的比值（Tp-e/QT）与ICD一级预防患者发生恶性室性心律失常的关系。方法分析我院2011年3月~2014年2月因严重慢性心功能不全（左室射血分数≤35%,纽约心功能分级为Ⅱ/Ⅲ级,且既往从未发生过室速或室颤等恶性心律失常）接受ICD（植入式心脏复律除颤器）一级预防的患者68例,对所有的患者随访18~38个月（平均26个月）。在随访过程中,患者根据是否发生终点事件分为高危组及低危组;本研究以SCD或室颤、室速作为终点事件。术前对所有的患者进行12导联心电图、心脏彩超、24 h动态心电图等检查,并分析Tpeak-Tend间期及（Tpeak-Tend）/QT。结果随访过程中,因ICD识别持续性室速或室颤而引发恰当放电的患者共11例,由ICD发现非持续性室速而不需治疗的患者共7例,故高危组患者共18例。从未发生室速或室颤者共50例为低危组。高危组患者的（Tp-e）105±15 ms明显高于低危组90±17 ms（P=0.003）;（Tpeak-Tend）/QT比值在高危组与低危早组相比有明显的统计学差异（0.27±0.04 vs 0.22±0.05,P=0.002）. TpTe/QT≥0.255预测ICD一级预防患者发生恶性室性心律失常风险的敏感性和特异性分别为72.2%和65.9%;TpTe≥103 ms预测ICD一级预防患者发生恶性室性心律失常风险的敏感性和特异性分别为66.7%和67.9%。结论 Tp-e间期、Tp-e/QT比值与ICD一级预防患者发生恶性室性心律失常的关系密切,Tpeak-Tend间期及Tp-e/QT比值越大,ICD一级预防患者发生恶性室性心律失常如室速、室颤的可能性越大。     

39例急性百草枯中毒心律失常分析

  目的 探讨急性百草枯中毒时心律失常发生类型及不同类型与死亡率的关系。方法 分析39例急性百草枯中毒患者的入院心律失常心电图,其中男15例,女24例,年龄20-~49岁。结果 25例次发生窦性心动过速;22例次室性早搏（7例室性早搏二、三联律）,3例次室性心动过速（其中1例转为室性扑动及心室颤动）和1例心室停博;8例次ST-T异常及T波、U波改变。发生室性心律失常的中毒患者死亡率高于其它类型心律失常患者发生室性心律失常的中毒患者死亡率高于其他类型心律失常患者。结论 急性百草枯中毒可出现多种心律失常,发生室性心律失常患者伴有较差预后。     

Electrophysiologic studies: recent experience at the Charleston Area Medical Center

Electrophysiologic studies (EPS) were performed in 122 patients for evaluation of supraventricular tachycardia (16 patients), syncope (30 patients), ventricular tachycardia (48 patients), sudden cardiac death (7 patients), and other reasons (21 patients). Sixty patients had an induced sustained supraventricular and/or ventricular arrhythmia. Therapy was rendered to all 60 patients based on the results of the EPS. The evaluation and treatment of supraventricular and ventricular arrhythmias is assisted by EPS. The capability of inducing the clinical arrhythmia, determination of the arrhythmia mechanism, and evaluation of the response to various pharmacologic agents improves therapeutic choices. Patient morbidity from cardiac arrhythmias is thereby reduced.     

肥厚性心肌病心源性猝死的危险因素分析

目的:分析肥厚性心肌病心源性猝死的危险因素。方法:收集发生心源性猝死的肥厚性心肌病患者32例,所有患者均经临床表现、实验室检查、心电图及超声心动图检查确诊,回顾性分析患者的临床资料。结果:单因素分析显示心脏骤停(心室颤动),自发性持续性室速,猝死家族史(≤40岁的一级亲属),晕厥(≥2次/年),左室厚度≥30mm,负荷或运动后收缩压反应异常(无变化或降低>10mmHg或升高<25mmHg),非持续性室速,左室流出道梗阻(压力差>30mmHg)等因素为肥厚性心肌病患者发生心源性猝死的危险因素(P<0.01)。多因素logistic分析显示心脏骤停(心室颤动),自发性持续性室速,猝死家族史及晕厥≥2次/年是肥厚性心肌病心源性猝死重要的危险因素。结论:多种危险因素与肥厚性心肌病心源性猝死密切相关,临床工作中应该积极应对。     

Life-threatening ventricular tachycardia and fibrillation induced by painless myocardial ischemia during exercise testing

The clinical importance of myocardial ischemia without associated symptoms in patients with atherosclerotic coronary disease has not been clarified. We present three patients in whom painless cardiac ischemia was associated with the induction of cardiac arrest and/or ventricular tachycardia/fibrillation. In the two surviving patients, programmed ventricular stimulation did not induce ventricular arrhythmias. In one patient, successful coronary bypass surgery resulted in the elimination of exercise-induced painless myocardial ischemia and associated ventricular fibrillation; the other patient suffered a myocardial infarction after which ischemia and ventricular tachyarrhythmias could not be reproduced with exercise testing. We conclude that painless myocardial ischemia can cause life-threatening arrhythmias and is, therefore, a potentially lethal phenomenon.     

Ventricular arrhythmias in patients undergoing noncardiac surgery. The Study of Perioperative Ischemia Research Group.

OBJECTIVE--To determine the incidence, clinical predictors and prognostic importance of perioperative ventricular arrhythmias. DESIGN--Prospective cohort study (Study of Perioperative Ischemia). SETTING--University-affiliated Department of Veterans Affairs Medical Center, San Francisco, Calif. SUBJECTS--A consecutive sample of 230 male patients, with known coronary artery disease (46%) or at high risk of coronary artery disease (54%), undergoing major noncardiac surgical procedures. MEASUREMENTS--We recorded cardiac rhythm throughout the preoperative (mean = 21 hours), intraoperative (mean = 6 hours), and postoperative (mean = 38 hours) periods using continuous ambulatory electrocardiographic monitoring. Adverse cardiac outcomes were noted by physicians blinded to information about arrhythmias. MAIN RESULTS--Frequent or major ventricular arrhythmias (greater than 30 ventricular ectopic beats per hour, ventricular tachycardia) occurred in 44% of our patients: 21% preoperatively, 16% intraoperatively, and 36% postoperatively. Compared with the preoperative baseline, the severity of arrhythmia increased in only 2% of patients intraoperatively but in 10% postoperatively. Preoperative ventricular arrhythmias were more common in smokers (odds ratio [OR], 4.1; 95% confidence interval [CI], 1.2 to 15.0), those with a history of congestive heart failure (OR, 4.1; 95% CI, 1.9 to 9.0), and those with electrocardiographic evidence of myocardial ischemia (OR, 2.2; 95% CI, 1.1 to 4.7). Preoperative arrhythmias were associated with the occurrence of intraoperative and postoperative arrhythmias (OR, 7.3; 95% CI, 3.3 to 16.0, and OR, 6.4; 95% CI, 2.7 to 15.0, respectively). Nonfatal myocardial infarction or cardiac death occurred in nine men; these outcomes were not significantly more frequent in those with prior perioperative arrhythmias, albeit with wide CIs (OR, 1.6; 95% CI, 0.4 to 6.2). CONCLUSION--Almost half of all high-risk patients undergoing noncardiac surgery have frequent ventricular ectopic beats or nonsustained ventricular tachycardia. Our results suggest that these arrhythmias, when they occur without other signs or symptoms of myocardial infarction, may not require aggressive monitoring or treatment during the perioperative period.     

心律转复除颤器植入术中避免常规 除颤阈值测试的随访观察

目的：探讨心律转复除颤器（ICD）和心室再同步心脏转复除颤器（CRT-D）植入术中未进行除颤阈值测试的患者,治疗恶性室性心律失常的有效性和安全性。方法：收集1999年10月至2008年8月间ICD植入术中未进行除颤阈值测试的21例ICD/CRT-D患者临床资料,应用体外程控仪获取存取信息并结合随访资料进行分析。结果：17例室性心动过速（室速）或心室颤动（室颤）患者植入ICD,4例心肌病合并严重心力衰竭患者植入CRT-D,术中均未进行除颤阈值测试。8例术后1周进行除颤阈值测试,其中3例（37.5%）未诱发出室速/室颤。程控随访1~7(4.2±1.9)年,21例未进行除颤阈值测试的患者中16例记录到室速或室颤事件,ICD成功除颤89阵（成功率100%）,抗心动过速起搏（ATP）终止室速120阵次（成功率51.1%）,低能量同步转复22阵次（成功率59.2%）。术后大多数患者联合应用抗心律失常药物,无恶性室性心律失常相关死亡病例。结论：ICD/CRT-D植入术中不常规进行除颤阈值测试可避免相关并发症发生,术后随访可有效治疗恶性室性心律失常,预防心脏性猝死。     

原发性高血压患者血压晨峰与心律失常及心肌缺血的关系

目的 探讨原发性高血压患者血压晨峰对心脏重构以及心血管事件的影响。方法2006年2月至2009年1月在本院就诊的高血压病患者中,按就诊顺序连续入选386例高血压患者,根据动态血压检测结果,分为晨峰组（146例）和非晨峰组（240例）,均同步记录24h动态血压和动态心电图,观察24h动态血压参数,24h动态心电图检出的房性、室性心律失常及ST段偏移;行超声心动图检测左室质量指数（LVMI）、左房内径等指标。结果晨峰组与非晨峰组LVMI分别为（119±21）g／m^2和（93±12）g／m^2（P〈0．01）;左房内径分别为（46±11）mm与（38±10）mm（P〈0．05）;房性早搏检出率分别为98．6％与84．2％（P〈0．05）;房性心动过速检出率分别为54．1％与20．8％（P〈0．01）;心房颤动检出率分别为24．0％与0（P〈0．01）;室性早搏和室性心动过速的检出率分别为79．5％与57．9％（P〈0．05）和6．8％与2．5％（P〈0．05）;检出ST段水平型压低率分别为33．6％与13．8％（P〈0．01）。两组左室肥厚的检出率分别为67．1％与30．4％（P〈0．01）。53．2％的心律失常和57．6％的ST段压低发作出现在清晨6：00～8：00。相关分析表明,清晨血压和血压晨峰升高与对应时域ST段压低呈正相关。结论与无血压晨峰的高血压病患者相比,具有血压晨峰的高血压患者左心室肥厚更显著,心律失常和心肌缺血更常见,且多出现在清晨。     

Survey of physician practices in managing patients with chronic ventricular arrhythmias

To better understand how physicians manage patients with chronic ventricular arrhythmias, questionnaires were mailed in July, 1989, to 680 internists, family physicians and cardiologists in West Virginia. Responses were returned by 35 per cent; those from 33 physicians who seldom prescribed drugs to treat arrhythmias were excluded from analysis. Quinidine and procainamide were the preferred first-line antiarrhythmics for 53.3 per cent and 24.3 per cent of physicians, respectively. Control of symptoms was listed as the usual indication for therapy by 32.2 per cent, and improvement in prognosis by 20.1 per cent. Physicians perceived a high prognostic benefit to antiarrhythmic treatment in patients with sustained ventricular tachycardia or history of cardiac arrest, and a generally low prognostic benefit in those with mitral valve prolapse. Opinion was divided on the prognostic benefit in other patient groups including those with frequent ventricular premature beats following myocardial infarction. These results help quantify current physician practices in managing patients with chronic ventricular arrhythmias.     

Automatic external defibrillators used by emergency medical technicians. A controlled clinical trial

In a randomized controlled clinical trial, the effectiveness of emergency medical technician (EMT) use of automatic external defibrillators (AEDs) was compared with EMT use of standard defibrillators for patients in cardiac arrest. A total of 321 cardiac arrest patients were treated during the study: 116 were treated by EMTs using the AED (AUTO group), 158 were treated by EMTs using the standard defibrillators (standard group), and 47 were treated by EMTs using the standard defibrillator when they were assigned to use the AED. There was no significant differences in hospital admission or discharge rates between the AUTO group (54% admitted, 28% discharged) and the standard group (52% admitted, 23% discharged) for patients in ventricular fibrillation (VF), for patients in non-VF rhythms, or for all patients combined. The only significant difference observed was in the time from power ON to first shock: 1.1 minutes average AUTO group and 2.0 minutes average standard group. The treatment groups did not differ significantly in sensitivity for VF (78% AED, 76% standard), specificity for non-VF rhythms (100% AED, 95% standard), or rates of defibrillation to a non-VF rhythm (62% AED, 57% standard). We conclude that in clinical outcomes and device performance, AEDs are comparable with standard defibrillators and should be considered an acceptable alternative. Automatic external defibrillators appear to have advantages over standard defibrillators in training, skill retention, and faster operation. Such devices can make early defibrillation available for a much larger portion of the population. They are a major innovation for the prehospital care of cardiac arrest patients.     

Cardiac arrhythmias during rewarming of patients with accidental hypothermia

Accidental hypothermia has a high mortality and is associated with cardiac arrhythmias. To determine the incidence of arrhythmias and their importance 22 patients with accidental hypothermia (core temperature less than 35 degrees C) were studied by 12 lead electrocardiography and continuous recording of cardiac rhythm. Although 14 of the patients died (64%), only six died while hypothermic. Prolongation of the Q-T interval and the presence of J waves were related to the severity of the hypothermia. Supraventricular arrhythmias, including atrial fibrillation, were common (nine cases) and benign. Ventricular extrasystoles were also common (10 cases), but ventricular tachycardia or fibrillation did not occur during rewarming. In eight patients who died while being monitored the terminal rhythm was asystole. There was no correlation between the severity of hypothermia or the rate of rewarming and the clinical outcome. In the absence of malignant arrhythmias there is no indication for using prophylactic antiarrhythmic treatment in patients with accidental hypothermia. The presence or absence of severe underlying disease is the main determinant of prognosis.     

Current treatment of patients surviving out-of-hospital cardiac arrest

Most out-of-hospital cardiac arrests result from the sudden onset of a sustained ventricular arrhythmia in the absence of a new myocardial infarction. Individuals who survive cardiac arrest are at high risk for recurrent arrhythmias and sudden unexpected death. To prevent recurrent cardiac arrest, effective treatment must be provided during hospitalization after the initial episode. Caring for the survivor of cardiac arrest requires a detailed clinical investigation to define the underlying cardiac anatomy and left ventricular function and to elucidate the mechanism and characteristics of the patient's arrhythmia. Appropriate antiarrhythmic therapy, such as drugs or a nonpharmacological intervention (eg, implantable cardioverter-defibrillator), is then selected based on these considerations. In addition, ischemia is treated aggressively with beta-adrenergic blocking agents and, when appropriate, with surgical coronary artery revascularization.     

Catheter and surgical treatment of cardiac arrhythmias

Over the past decade, numerous impressive advances have been made using nonpharmacologic methods for control of cardiac arrhythmias. These methods include surgical or catheter ablation of abnormal foci. Current techniques involve catheter ablation of the atrioventricular junction to control supraventricular arrhythmias. In addition, surgical techniques have proved to be remarkably safe and effective for treatment of patients with accessory pathways and those with atrioventricular nodal reentrant tachycardia. Patients with drug-refractory ventricular tachycardia may benefit from surgical resection of the ventricular tachycardia focus. The use of these interventional methodologies has radically altered the approach to management of patients with drug-refractory cardiac arrhythmias.     

Caffeine and ventricular arrhythmias. An electrophysiological approach

Little information is known regarding caffeine's effect on the substrate supporting sustained ventricular arrhythmias. This prospective study evaluated the effect of coffee (275 mg of caffeine) on this substrate with programmed ventricular stimulation in 22 patients with a history of symptomatic nonsustained ventricular tachycardia, ventricular tachycardia, or ventricular fibrillation. Patients underwent electrophysiological testing before and 1 hour after coffee ingestion. Mean (+/- SEM) plasma caffeine level achieved after coffee consumption was 6.2 +/- 0.5 mg/L. Mean plasma catecholamine and potassium values were not altered significantly 1 hour following caffeine ingestion. The number of extrastimuli required to induce an arrhythmia was unchanged in 10 patients (46%), increased in six (27%), and decreased in six (27%). Rhythm severity was unchanged in 17 patients (77%), more severe in two (9%), and less severe in three (14%). In those patients with clinical ventricular arrhythmias, caffeine did not significantly alter inducibility or severity of arrhythmias, suggesting little effect on the substrate supporting ventricular arrhythmias.     

丙戊酸钠治疗心律失常103例临床初步观察

本文报道口服丙戊酸钠治疗103例各型心律失常,显效47例(45.6%),好转33例(32.1%),总有效率为77.7%,其中室性早搏有效率为78%;房性早搏75%,室上性心动过速80%。本品的起效时间,在显效病例中,3天内、1周和2周完全复律者分别为17.0%,46.8%和78.7%。不良反应有恶心、呕吐、上腹部不适、嗜睡、眩晕、头昏和脱发等。     

心肌梗塞患者心室晚电位的临床和随访分析

目的：研究心室晚电位（ＬＰ）与梗塞部位、恶性室性心律失常和心功能的关系，以及ＬＰ对心肌梗塞（ＭＩ）后发生室性心动过速／心室颤动（ＶＴ／ＶＦ）和猝死的预测作用。方法：用晚电位记录仪对１６８例ＭＩ患者进行检测和随访分析。结果：本组ＭＩ患者中ＬＰ的阳性检出率为２７％，多壁ＭＩ组ＬＰ阳性率明显高于前（间）壁ＭＩ组（Ｐ＜００５），ＶＴ／ＶＦ和猝死患者的ＬＰ阳性率明显高于无ＶＴ／ＶＦ患者（Ｐ＜００１），ＭＩ伴心功能不全者ＬＰ阳性率明显高于有ＭＩ但心功能Ⅰ级者（Ｐ＜００１）。结论：ＬＰ与ＭＩ范围的大小、心脏的功能状态以及ＶＴ／ＶＦ或猝死有密切关系，但陈旧性ＭＩ发生猝死可能与ＬＰ关系不大     

Arrhythmias in dilated cardiomyopathy

Sixty-five patients with dilated cardiomyopathy underwent 24 hour electrocardiographic monitoring: 62 (95.4%) showed ventricular arrhythmias and 52 (80%) complex ventricular arrhythmias (multiform ventricular extrasystoles, paired ventricular extrasystoles and ventricular tachycardia). Complex ventricular arrhythmias correlated significantly with some haemodynamic indices of ventricular dysfunction: patients with multiform and paired ventricular extrasystoles and with ventricular tachycardia had lower values of ejection fraction (31.9 +/- 11.8%, P = 0.002) and of cardiac index (2.9 +/- 0.7 litres/min/m2, P = 0.029) than the others (41.1 11.1% and 3.5 +/- 0.9 litres/min/m2 respectively). Patients were followed for a period of 30 +/- 18 months (20 days to 64 months). During follow-up 19 died and mortality was higher among patients with multiform and paired ventricular extrasystoles and/or ventricular tachycardia. Complex ventricular arrhythmias are frequent in dilated cardiomyopathy: ventricular tachycardia and multiform and paired ventricular extrasystoles seem to be related to a more depressed ventricular function and to a poor prognosis. The importance of antiarrhythmic treatment in these patients has still to be evaluated.     

Prognostic factors affecting the all-cause death and sudden cardiac death rates of post myocardial infarction patients with low left ventricular ejection fraction

Background Post myocardial infarction （post-MI） patients with low left ventricular ejection fraction （LVEF） have been candidates for an implantable cardioverter-defibrillator （ICD） since the Multicenter Automatic Defibrillator Implantation Trail Ⅱ （MADIT Ⅱ）. However, due to the high costs of ICDs, widespread usage has not been accepted. Therefore, further risk stratification for post-MI patients with low LVEF may aid in the selection of patients that will benefit most from ICD treatment.
Methods Four hundred and seventeen post-MI patients with low LVEF （≤35%） were enrolled in the study. All the patients received standard examination and proper treatment and were followed up to observe the all-cause death rate and sudden cardiac death （SCD） rate. Then COX proportional-hazards regression model was used to investigate the clinical factors which affect the all-cause death rate and SCD rate.
Results Of 55 patients who died during （32±24） months of follow-up, 37 （67%） died suddenly. After adjusting for baseline clinical characteristics, multivariate COX proportional-hazards regression model identified the following variables associated with death from all causes： New York Heart Association （NYHA） heart failure class ≥Ⅲ （Hazard ratio： 2.361）, LVEF ≤20% （Hazard ratio： 2.514）, sustained ventricular tachycardia （Hazard ratio： 6.453）, and age 〉70 years （Hazard ratio： 3.116）. The presence of sustained ventricular tachycardia （Hazard ratio： 6.491） and age ≥70 years （Hazard ratio： 2.694） were specifically associated with SCD. Conclusions In the post-MI patients with low LVEF, factors as LVEF ≤20%, age ≥70 years, presence of ventricular tachycardia, and NYHA heart failure class ≥111 predict an adverse outcome. The presence of sustained ventricular tachycardia and age ≥70 years was associated with occurrence of SCD in these patients.