Significance of prolonged electrocardiographic pauses in sinoatrial disease: sick sinus syndrome

Eighty-four patients (2.6%) were found to have prolonged (≥ 2.0 seconds) sinoatrial pauses in a review of 3,259 consecutive patients who had 24-hour Holter electrocardiographic studies. Pauses averaged 2.6 ± 1.5 seconds (± standard deviation) (range 2.0–15.2). In 17 (20%), no underlying heart disease was found and in 8 (10%), prolonged pauses appeared to be drug-induced. No relation was found between length of pauses and presence of symptoms or risk of death. Twenty patients received a pacemaker. Pacemaker recipients were older and more likely to be male and to have symptoms, although 7 were asymptomatic. Patients who received a permanent pacemaker were not different from nonrecipients with respect to average longest pause, mechanisms of pause, underlying heart condition or average time of follow-up. However, the survival rate was not improved by permanent pacemaker implantation. Of the 17 patients who died, only 3 died of cardiac causes; none had a recognizable bradycardic cause. Thirteen who initially had syncope did not receive a pacemaker; 2 died of noncardiac causes and none had a subsequent syncopal episode. Ten patients with a syncopal episode received a permanent pacemaker; 3 subsequently died and 3 survivors continued to complain of dizziness. Of the 37 patients who did not have any symptoms on initial examination, only one subsequently had a syncopal episode. Thus, length of sinoatrial pauses correlates poorly with symptoms and does not predict sudden death. Unless prolonged sinoatrial pauses are shown to cause symptoms, such pauses per se are not an indication for permanent pacemaker implantation.     

Ventricular arrhythmia in X-linked Emery-Dreifuss muscular dystrophy: a lesson from an autopsy case

Emery-Dreifuss muscular dystrophy (EDMD) is a distinctive form of muscular dystrophy which is often associated with cardiac abnormalities. Conduction disturbances are frequently observed, and may necessitate pacemaker implantation to prevent sudden death. In this case report, we present an autopsy of a 31-year-old man with X-linked EDMD who developed only minimal skeletal muscle symptoms, and who died from ventricular arrhythmia despite undergoing a previous pacemaker implantation. Ventricular arrhythmias in X-linked EDMD patients are also discussed.     

Significance of asymptomatic bradycardia for subsequent pacemaker implantation and mortality in patients >60 years of age

Sinus bradycardia may be more significant in older patients than in a younger group because it could signal important or advanced conduction system and/or cardiac disease potentially modifiable with pacemaker implantation. We evaluated the clinical need for subsequent pacemaker implantation and mortality rate in outpatients >60 years of age with relatively asymptomatic bradycardia (heart rate <55 beats/min without a subsequent pacemaker implantation within 2 weeks) or not (heart rate 60 to 70 beats/min). The 2 groups were matched against pacemaker implantation and death records but without data on indication or cause. Kaplan-Meier survival curves and univariate and multivariable models examined pacemaker implantation and all-cause mortality. The cohort consisted of 470 patients with and 2,090 without asymptomatic bradycardia. Mean follow-up period was 7.2 ± 2.9 years during which 137 patients (5.4%) underwent pacemaker implantation and 748 (29.2%) died. Incidence of pacemaker placement was higher in the bradycardia cohort (9% vs 5%, p <0.001). The higher incidence of pacemaker implantation did not appear in the first 4 years. Univariate analysis showed no increase in mortality in the bradycardia group (hazard ratio 0.87, 95% confidence interval 0.72 to 1.04, p = 0.130), whereas multivariable analysis showed protection (hazard ratio 0.78, 95% confidence interval 0.65 to 0.94, p = 0.010). In conclusion, older patients with asymptomatic bradycardia have a very low rate of pacemaker implantation, annualized to <1% per year. Their higher rate of pacemaker implantation compared to outpatients without bradycardia shows a latency period of approximately 4 years. It has no adverse impact on all-cause mortality and may even be protective.     

292例永久心脏起搏器置入术患者的长期随访分析

目的 分析永久性人工心脏起搏器置入术后患者长期随访的的临床结果.方法 回顾性分析我院292例置入永久性起搏器后患者术后随访及程控资料,随访时间1～10年,随访内容包括患者的临床症状、心功能情况、生存率、起搏器故障发生情况,行多导联心电图、胸部X线及超声心动图检查,根据需要对部分患者行起搏方式及起搏参数调整.结果 292例患者中,术前主诉的心动过缓相关症状,包括头昏、黑矇、胸闷、心悸、气短等症状均消失或减轻;患者的心功能有所改善,平均LVEF值由术前的0.43±0.07提高到术后的0.57±0.06（P＜0.05）,运动耐量提高,生活质量改善.随访期间,12例患者死亡,其中4例患者因脑血管意外死亡,5例患者因心功能衰竭死亡,3例患者因恶性肿瘤死亡.共发现各种并发症39例,包括起搏器囊袋破溃、起搏电极脱位、起搏或感知不良、心律失常、膈肌刺激、起搏器综合征等,均及时以不同的方法处理.结论 基层医院对置入永久人工心脏起搏器后的患者进行定期随访非常重要,可及时发现和处理与起搏器相关的并发症及排除起搏故障.     

Initial United Kingdom experience with the use of permanent, biventricular pacemakers: implantation procedure and technical considerations.

AIMS: To describe the institution of a biventricular pacing programme with particular reference to the implantation procedure and new technological considerations. METHODS AND RESULTS: Analysis of outcomes of a consecutive series of 54 patients undergoing attempted biventricular pacemaker implantation between February 1998 and April 1999. Successful implantation was achieved in 49 of the 54 patients (91%). Five patients required lead repositioning after initial successful implantation. Left ventricular lead pacing thresholds were found to be satisfactory and stable in the long term, with pacing thresholds of 1.3 V, 1.9 V and 1.6 V at implantation, 1 and 3 months, respectively. Left-sided lead function was not dependent on lead position within the tributaries of the coronary sinus. The implantation procedure was found to be safe, although one patient died during long-term follow-up. CONCLUSION: With appropriate previous experience in complex and coronary sinus pacing and with access to up-to-date pacemaker and lead technology, a biventricular pacemaker implantation service can be instituted with good medium-term results.     

Complete heart block in acute myocardial infarction: drug therapy

A prospective investigation of medication in the treatment of complete heart block in acute myocardial infarction (AMI) was undertaken in the Coronary Care Unit of the Municipal Hospital, Copenhagen, during the period Nov. 24, 1967, to August 31, 1970.The material comprises 32 consecutive cases, corresponding to 8 per cent of all patients with verified acute myocardial infarction treated in the Unit during the same period. Treatment consisted in atropine, isoprenaline, and occasionally corticosteroids.Twelve patients died. In five the medication was without sufficient effect, and transvenous intracardial demand pacemakers were therefore employed. Three of these patients died. In the remaining nine fatal cases, sinus rhythm had been achieved in seven before death. The causes of death in these cases were: cardiac collapse, pulmonary embolism, or myocardial rupture. Two patients died after ventricular fibrillation.The mortality rate among the patients admitted in a state of cardiogenic shock was high, but with these exceptions it was not possible to predict the prognosis from the condition on admission.Eight out of 15 patients with infarctions of the anterior wall and 3 out of 16 patients with infarctions of the posterior wall died. The highest mortality rate was encountered in the combination of anterior wall infarction and a widened QRS complex.It cannot be ruled out that the chronotropic treatment may have resulted in an increased tendency to ectopic ventricular dysrhythmias, but this did not influence the mortality rate.The results obtained correspond to those observed in comparable materials using prophylactic pacemaker technique.It is concluded that by medication it is as a rule possible to achieve results similar to those of pacemaker therapy in complete heart block in acute myocardial infarction. However, pacemaker implantation may be life-saving in some cases and is indicated under all circumstances in Stokes-Adams attacks, persistent bradycardia with reduced cardiac output, and in repeated ventricular tachycardia during medication. In addition, prophylactic pacemaker implantation should be considered in anterior wall infarction with widened QRS complex, as this type of patient may frequently and suddenly develop complete heart block directly from sinus rhythm.     

永久起搏器和埋藏式心脏复律除颤器（ICD）在遗传性长QT综合征患者中的应用

目的总结合并窦性心动过缓的遗传性长QT综合征（以下简称遗传性LQTS）患者植入永久起搏器和埋藏式心脏复律除颤器（以下简称ICD）的治疗效果,对比分析这两种治疗在预防患者猝死中的差异。方法对我院从2003年6月到2013年6月出院诊断为遗传性LQTS合并窦性心动过缓、植入了永久起搏器或ICD的全部21例患者,结合门诊、电话和程控随访了解患者的生存状况、手术并发症以及晕厥、室性恶性心律失常的发作情况。结果起搏器组男性2例,女性9例,年龄39.3±14.3岁,随访时间50.6±26.3个月,1例患者猝死,2例患者再发晕厥前兆,其中1例最终更换为ICD。ICD组男性2例,女性8例,年龄34.5±11.9岁,随访时间61.4±43.5个月,3例患者接受了ICD的适当治疗,另2例患者接受了ICD的不适当治疗,1例患者术后出现囊袋感染,1例患者更换为永久起搏器。治疗有效率在起搏器组及ICD组分别为72.7%（8/11）和100.0%（10/10）,未达到统计学差异（p=0.21）。不良事件发生率在起搏器组及ICD组分别为27.3%（3/11）和30.0%（3/10）,也未达到统计学差异（p=0.63）。结论对于不能植入ICD的合并窦性心动过缓的遗传性LQTS患者,植入永久起搏器可能是一个较好的替代方法,但对于QTc≥539ms的患者,只有植入ICD才能预防猝死。植入ICD后长期无心脏事件发生的患者,根据患者意愿,可考虑更换为永久起搏器。     

Sudden death after radiofrequency ablation of the atrioventricular node in patients with atrial fibrillation

OBJECTIVES: We evaluated the incidence and predictors of sudden death after atrioventricular (AV) node ablation and pacemaker implantation. BACKGROUND: Sudden death may occur after radiofrequency catheter ablation of the AV node and pacemaker implantation in patients with atrial fibrillation (AF). Whether it is related to the procedure or to pre-existing heart disease remains unclear. METHODS: All patients who had radiofrequency catheter ablation of the AV node and pacemaker implantation for rate control of medically refractory AF were identified retrospectively and observed prospectively. All patients with sudden death after ablation were identified. The relationship between the procedure and sudden death was defined on the basis of the time between the two as "likely," "possibly" or "unlikely." RESULTS: Of 334 consecutive patients with AF who underwent AV node ablation, nine had sudden death after the ablation. Four patients (1.2%) had sudden death likely related to the procedure: in 3 patients, arrest occurred within 48 h after the procedure; in one patient, arrest occurred four days after the procedure. In three other patients (0.9%), sudden death was possibly related to the procedure because the event occurred within three months afterward. The remaining two deaths were unrelated to the procedure. Diabetes, New York Heart Association functional class (>or=II), preprocedure ventricular arrhythmia, mitral or aortic stenosis, aortic regurgitation and chronic obstructive pulmonary disease were independent predictors for sudden death. CONCLUSIONS: Sudden death likely or possibly related to catheter ablation occurred in 7 of 334 patients (2.1%). Risk of sudden death is highest within two days after the procedure.     

Large right atrial thrombosis. Rare complication during permanent transvenous endocardial pacing.

Right atrial thrombosis is a rare complication of permanent endocardial pacing. We report two cases with large right atrial thrombi which occurred during permanent endocardial electrical stimulation. Both patients were women, aged 83 and 89 years, who died suddenly, respectively, one month and 24 days after pacemaker implantation. At the time of death the two patients were in severe persistent refractory congestive heart failure despite appropriate medical treatment. At necropsy large mobile right atrial thrombi were found in both cases.     

Permanent cardiac pacing in patients on chronic renal dialysis

We reviewed the need for permanent pacemaker implantation in patients with chronic renal failure who were undergoing dialysis. During a 10-year span, there were seven patients undergoing dialysis in whom a permanent pacemaker was indicated; this was an incidence of 0.68%. During that same period, the general patient population of this hospital had an incidence of permanent pacemaker implantation of about 0.29%. The need for hemodialysis in the same hospital population was 0.51%. Of the seven patients, four had universal pacemakers. Cardiac function was evaluated via radionuclide angiography. Three of the four patients showed improvement with dual-chambered pacing over ventricular pacing. Permanent pacemaker implantation was often needed after initiation of dialysis from 6 to 51 months with a mean of 21 months. During the follow-up period, three patients died from 7 months to 6 years after the institution of permanent pacing; their deaths were secondary to renal disease.     

Cardiologic evaluation in a family with Emery-Dreifuss muscular dystrophy

Emery-Dreifuss muscular dystrophy is an X-linked recessive condition characterized by mild muscular weakness predominantly in a humero-peroneal distribution with variable facial involvement. Onset is in childhood with slow progression of weakness. The disease is often associated with cardiac involvement, mainly with bradyarrhythmias which might be responsible for sudden death. The most striking finding derived from the literature is the high incidence of sudden death; in the 7 large families described, out of the 79 reported patients 32 died suddenly at a young age (between 25 and 56 years). We performed a cardiologic evaluation of 11 subjects of a large italian family with affected males in four generations: 5 affected males (3 adults and 2 boys), 3 carriers and 3 healthy relatives (2 females and 1 male). Supraventricular arrhythmias were documented either in the dystrophic males or in the carriers. There was no correlation between the severity of cardiac rhythm abnormality and the severity of muscular weakness in the affected males, 3 of whom required pacemaker insertion. All the carriers were free of muscular involvement, but showed arrhythmias of variable degree, in one case requiring pacemaker insertion. In conclusion our data indicate an extremely high incidence of bradyarrhythmias, sometimes serious, in patients with Emery-Dreifuss muscular dystrophy. Holter monitoring is therefore mandatory and electrophysiological study is sometime necessary. Because of the high risk of sudden death in adult patients, we recommend permanent pacemaker implantation even in asymptomatic subjects, as soon as bradyarrhythmias are detected.     

房室结消融加永久起搏器植入治疗难治性房扑房颤

目的评价房室结消融加永久起搏器植入治疗难治性房扑房颤的安全性和有效性。方法在临时起搏器保护下，对一例阵发性房扑房颤患者实施射频消融房室结并植入永久起搏器；观察其术中、术后及随访情况。结果该患者手术成功，未发生与射频相关性猝死；术后生活质量改善。结论房室结消融加永久起搏器植入可作为多种治疗无效的房扑房颤患者控制心室率的适当方法，该方法简单有效。     

永久心脏起搏治疗对儿童患者长期预后的影响

目的 了解儿童患者接受永久心脏起搏治疗的安全性及有效性,并评价其长期预后.方法 收集1977年4月1日至2011年4月1日在阜外心血管病医院接受永久心脏起搏治疗的所有患儿（≤14周岁）的临床资料.了解儿童起搏患者的基础心脏疾病、起搏器植入适应证、并发症情况以及长期预后.结果 85例患儿（男52例,女33例）接受永久心脏起搏治疗,年龄2个月～14岁,平均（8.1＆#177;4.2）岁;最常见的基础心脏疾病为先天性心脏病50例（58.8％）,其次为病毒性心肌炎8例（9.4％）,4例（4.7％）患儿合并其他基础心脏疾病（长QT综合征,室性心动过速和肥厚型心肌病）,23例（27.1％）患者无伴发疾病.起搏治疗适应证分别为房室阻滞（67例,78.8％）、病态窦房结综合征（16例,18.8％）、长QT综合征（2例,2.4％）,房室阻滞的患儿绝大多数（43例,64.2％）为外科修补术后.患儿随访1～291（73＆#177;62）个月,18例患儿失随访,随访率为78.8％.随访期间,20例（29.9％）患儿因电池耗竭更换起搏器.并发症的发生率为11.9％（13例次/109次手术）,包括导线移位（5例,4.6％）、囊袋内感染（5例,4.6％）、血肿（2例）和导线断裂（1例）.3例患儿死亡,基础心脏病均为结构性心脏病.结论 儿童患者植入永久心脏起搏器治疗是安全、有效的.应根据患者的年龄、基础心脏病等情况选择合适的导线植入途径和起搏方式.儿童患者接受起搏治疗的长期预后主要与基础心脏疾病相关.     

Prevalence, circumstances, mechanisms, and risk stratification of sudden cardiac death in unipolar single-chamber ventricular pacing.

BACKGROUND. Permanent cardiac pacing is well established for the improvement of prognosis and quality of life in patients with severe bradycardia. However, sudden cardiac death still remains an unresolved problem, as it occurs in approximately 20-30% of paced patients. This 2-year follow-up study was directed at prospectively assessing prevalence, circumstances, and mechanisms of sudden death in 2,021 permanently paced patients. METHODS AND RESULTS. During the observation period, 220 patients (11%) died (mean pacing interval, 50.5 +/- 7 months). Lethal cerebrovascular events in 66 of 220 patients (30%) and sudden death in 49 of 220 patients (23%) were the two most frequently reported modes of death. Nonsudden (first year, 20%; subsequent years, 6.9%; p less than 0.01) and sudden death mortality rate (4% versus 1.8%, p less than 0.05) were highest during the first year. Mortality was unrelated to the patient's activity status at the time of death. Sudden cardiac death occurred more often in male patients (increased risk, 1.7 versus female patients; p less than 0.001) and patients younger than 60 years of age (5.2 versus patients older than 60 years, p less than 0.001). Patients with severe bradycardia (sudden death rate, 28%), severe atrioventricular block (25%), or atrial fibrillation with low ventricular rate (25%) before pacemaker implantation were more likely to suffer from sudden cardiac death than patients with previous syncopal attacks (sudden death rate, 15%) or sick sinus syndrome (17%). The highest incidence of sudden death was observed in patients with bifascicular and trifascicular bundle branch block. In this group, 35% of patients died suddenly during the follow-up period compared with 18% of patients without bundle branch block. In a subsequent study in 90 consecutive patients with various types of bundle branch block, undersensing of up to 13% of ectopic ventricular beats occurred in patients with bifascicular block. Pacing-induced tachyarrhythmias and ventricular fibrillation were documented in 10% of undersensed ectopic ventricular beats as well as in the setting of atrial fibrillation associated with ventricular arrhythmias. CONCLUSIONS. Young age, male sex, and a severely diseased heart indicated by the presence of bifascicular and trifascicular bundle branch block are the strongest predictive clinical parameters for sudden cardiac death, especially in the first year after pacemaker implantation.     

Cardiac pacing in West Africa: feasibility, problems, and perspectives

BACKGROUND: The frequency of conductive trouble is not know in West-Africa where the evacuation to Europe and the cardiology institute of Abidjan has been for long time the only possibility to implant stimulators. We analyse our experience, the problems ant the perspectives. METHODS: Over a three year period 92 patients (47 men, 45 women) were implanted using new (47%) or a recycled pacemaker. The technique used was essentially endoveinous (sub-clavicular puncture) except 2 children. The medium length of treatment was 24 months. RESULTS: Syncope was noticed at the entrance in most 50% of cases. The degenerative etiology was dominant in 85%. Most cases (87%) used the VVI mode. Complications comprised 3 leads deplacements, 5 infections, 1 pacemaker syndrome and 1 death by mesenteria ischemia. Seven patients died later without any relation of cardiac pacing. CONCLUSION: Despite an intrinsically high cost, pacemaker implantation is feasible and useful in selected indications in developing countries.     

Seasonal distribution of pacemaker implantation for symptomatic bradycardia

Permanent cardiac-pacemaker therapy is widely recognized as beneficial in the treatment of various types of symptomatic bradycardia. However, the seasonal distribution of pacemaker implantation has never been discussed. The purpose of this study was to investigate the seasonal distribution of pacemaker implantation in a large population of patients with symptomatic bradycardia. The study population consisted of 904 patients who underwent implantation of a new permanent pacemaker between January 1999 and December 2001 and were registered in the database of CPI Company in Taiwan. The number of pacemaker implantations in each month was analyzed to investigate the seasonal distribution of pacemaker implantations in a year. The number of patients who underwent pacemaker implantation between October and December was significantly higher than that of other seasons (P < 0.007). The results indicate that there is a tendency for bradyarrhythmic patients to have symptoms between October and December.     

Permanent and temporary pacemaker implantation after orthotopic heart transplantation

PURPOSE:To determine the indication for and incidence and evolution of temporary and permanent pacemaker implantation in cardiac transplant recipients. METHODS: A retrospective review of 114 patients who underwent orthotopic heart transplantation InCor (Heart Institute USP BR) between March 1985 and May 1993. We studied the incidence of and indication for temporary pacing, the relationship between pacing and rejection, the need for pemanent pacing and the clinical follow-up. RESULTS: Fourteen of 114 (12%)heart transplant recipients required temporary pacing and 4 of 114 (3.5%) patients required permanent pacing. The indication for temporary pacing was sinus node dysfunction in 11 patients (78.5%) and atrioventricular (AV) block in 3 patients (21.4%). The indication for permanent pacemaker implantation was sinus node dysfunction in 3 patients (75%) and atrioventricular (AV) block in 1 patient (25%). We observed rejection in 3 patients (21.4%) who required temporary pacing and in 2 patients (50%) who required permanent pacing. The previous use of amiodarone was observed in 10 patients (71.4%) with temporary pacing. Seven of the 14 patients (50%) died during follow-up. CONCLUSION: Sinus node dysfunction was the principal indication for temporary and permanent pacemaker implantation in cardiac transplant recipients. The need for pacing was related to worse prognosis after cardiac transplantation.     

埋藏式心脏起搏25例死因探讨

本文报道我院1981年至1991年使用埋藏式心脏起搏器345例次(274例),经平均59个月随访,死亡25例,死亡率9.1%。死因依次为进行性心力衰竭、猝死、肾功衰竭、并发恶性肿瘤、脑出血、肝硬化大呕血等。提出严格掌握适应证、选用合适的起搏系统、加强对高危患者的随访和处理有助于降低死亡率。     

单根电极导线心室起搏双腔感知双反应方式起搏器远期效果分析

目的　探讨单根电极导线心室起搏双腔感知双反应方式起搏器 (VDD起搏器 )的远期临床使用效果。方法　 1993- 0 3～ 2 0 0 2 - 0 5共植入单根电极导线的VDD起搏器 16例 ,其中男性 12例 ,女性 4例 ,年龄 4 9～ 75岁 ,平均年龄 ( 6 4 4± 7 8)岁。均为窦性心律正常伴完全性房室传导阻滞或高度房室传导阻滞者。常规采用穿刺锁骨下静脉方法植入电极导线 ,起搏器植入电极导线插入的同侧。结果　随访时间 112～ 1个月 ,平均 ( 6 8 8±6 3)个月。全部患者植入后 ,心功能提高 ,临床症状消失 ,长期随访生活质量明显改善 ,无心房感知不良者。 1例因冠心病合并心衰于随访 4 2个月死亡外 ,其余均健在 ,无失访者。结论　只要适应证选择合适 ,使用VDD起搏器手术简单易于操作 ,又可减轻病人负担并能取得最佳的治疗效果 ,心内科同道应重视这类起搏器的选用 ,特别是对于经济不发达地区更为重要     

家族性电紊乱性心脏病未植入心律转复除颤器患者的长期随访研究

目的 研究家族性电紊乱性心脏病高危患者,未植入心律转复除颤器(ICD)的长期预后.方法 13例患者中11例长QT综合征(LQTS)、2例Brugada综合征,均有心脏性晕厥.男性4例,女性9例,平均年龄(44±19)岁.6例(46%)因心跳骤停住院治疗.4例LQTS植入起搏器,平均随访(7±4)年.结果 11例(85%)患者仍然发作晕厥,1例心脏骤停首次入院,5例(39%)心脏骤停再入院,2例LQTS死亡,其中1例(0.8%)猝死.结论 LQTS和Brugada综合征患者一旦出现晕厥,以后会反复发作,如果没有条件接受ICD治疗,其他的药物治疗、医生的密切监控随访、指导患者避免触发因素和针对家属的心肺复苏训练同样非常重要.