Left ventricular pacing through coronary sinus tributaries: initial experience.

BACKGROUND: Left ventricular pacing is increasingly being used as a part of biventricular pacing in congestive heart failure but data on safety, feasibility, reliability and lead maturation are sparse. METHODS AND RESULTS: Seventeen patients (13 males and 4 females) with persistent symptomatic degenerative complete heart block underwent temporary left ventricular pacing by a left subclavian puncture through the coronary sinus to its tributaries using a unipolar permanent pacing lead connected to an external pulse generator. The left ventricular pacing was done for two weeks. Permanent right ventricular apical pacing was also done at the same time through a right cephalic vein cut-down or subclavian puncture and the pacing rate was kept below that of the initial left ventricular pacing rate. Pacing parameters of the left and right ventricles were assessed at the time of implantation and at two weeks. Out of 17 patients, left ventricular pacing was successful in 11 (67.7%) patients. The time taken for the total procedure was 56+/-18.1 min. Lead displacement was noted in one patient without loss of pacing. At the time of implant and after two weeks, left ventricular pacing threshold, impedance, R wave height and slew rate were not different as compared to right ventricular pacing. Holter recording for 24 hours revealed regular left ventricular pacing at the end of two weeks in all patients. CONCLUSIONS: The present study shows that left ventricular pacing through coronary sinus tributaries is feasible and reliable. Acute and subacute maturation of left ventricular pacing are similar to right ventricular apical pacing.     

117例双心室再同步起搏器植入术并发症分析

目的　双心室同步起搏已经被证明可有效改善充血性心力衰竭患者的心功能。进行双心室再同步治疗 (cardiacresynchronizationtherapy ,CRT)的技术关键是植入左心室导线。植入左心室导线技术难度大 ,操作复杂 ,有一定的并发症发生率 ,本文分析了 117例双心室起搏器植入术并发症。方法　充血性心力衰竭伴心室内阻滞患者 117例 ,其中男性 86例 ,女性 31例 ,平均年龄 (5 3 0 0±8 2 5 )岁。患者在进行逆行冠状静脉窦造影后 ,经冠状静脉窦插入导线至心脏静脉 (主要为心脏后静脉和侧后静脉 )进行左心室起搏。然后植入右心房和右心室电极导线。结果　 117例患者中 111例成功植入双心室起搏系统 ,成功率为 95 %。主要植入术的相关并发症包括 :冠状静脉窦夹层 4例(3 4 % % ) ,膈肌刺激需要重新植入 2例 (1 7% ) ;电极导线脱位 2例 (1 7% ) ,结论　双心室再同步治疗 (cardiacresynchronizationtherapywithbiventricularpacing)起搏器植入术有一定的术中并发症和一定的风险 ,术前应掌握好适应证并作好充分的准备 ,术中必须规范操作 ,严密观察 ,以减少并发症     

双心室起搏治疗心力衰竭的初步经验

目的 介绍双心室起搏治疗心力衰竭衰竭的初步经验。方法 ６例充血性心力衰竭患者,男性４例,女性２例,平均年龄５８岁;心功能ＮＹＨＡ分级：Ⅲ～Ⅳ级：均伴有心室内阻滞。患者均植入了三腔双心室起搏器,左心室导线通过冠状静脉窦插入心脏静脉侧分支或侧后分支。结果 所有患者植入起搏器后临床症状改善,超声心动图检查显示左心室收缩功能和同步性改善,舒张期充盈改善,二尖瓣返流减少,此外,双心定起搏后,所有病例ＱＲＳ时     

心室再同步化起搏的心电图表现及随访

目的探讨不同心室起搏部位体表十二导联心电图的变化及在双心室再同步起搏(CRT)随访中的应用。方法22例资料完整的充血性心力衰竭患者进行双心室再同步起搏治疗,其中21例经静脉置入左室导线,1例因冠状静脉窦畸形经胸左室外膜导线置入;右室导线均放置在心尖部。22例分别记录无起搏、右室起搏、左室起搏及双心室同步起搏四种不同状态下的十二导联心电图。结果22例术前心电图显示完全性左束支传导阻滞(CLBBB)16例,完全性心室内传导阻滞6例,行右室心尖部起搏时胸前导联(V1)均呈CLBBB型,肢体导联额面电轴左偏,Ⅰ导联呈r、R型占100%,左室起搏时胸前导联(V1)均呈右束支传导阻滞(CRBBB)型,额面电轴右偏,Ⅰ导联呈q、Q、QS型20例,占91%;双心室同步起搏后胸前导联(V1)呈CLBBB型13例,呈CRBBB型9例,额面电轴均右偏,Ⅰ导联呈q、Q、QS型占86.5%。结论不同部位心室起搏具有不同的心电图表现,双心室同步起搏具有特征性的心电图形态,CRT随访时通过对心电图形态和时限的观察有助于判断是否实现真正有效的双心室再同步起搏。     

Six year experience of transvenous left ventricular lead implantation for permanent biventricular pacing in patients with advanced heart failure: technical aspects

BACKGROUND—Biventricular pacing has been proposed as an adjuvant to optimal medical treatment in patients with drug refractory heart failure caused by chronic left ventricular systolic dysfunction and intraventricular conduction delay.OBJECTIVE—To assess the technical feasibility and long term results (over six years) of transverse left ventricular pacing with the lead inserted into a tributary vein of the coronary sinus.SUBJECTS—From August 1994 to February 2000, left ventricular lead implantation was attempted in 116 patients who were eligible for biventricular pacing (mean (SD) age 67 (9) years, New York Heart Association (NYHA) functional class III/IV, left ventricular ejection fraction 22 (6)%, QRS duration 185 (26) ms).RESULTS—The overall implantation success rate was 88% (n = 102). A learning curve was indicated by a progressive increase in success from 61% early on to 98% in the last year. The mean pacing threshold was 1.1 (0.7) V/0.5 ms at the time of implantation and increased slightly up to 1.9 (0.9) V/0.5 ms at the end of the follow up period (15 (13) months). The rate of acute and delayed left ventricular lead dislodgement decreased from 30% in the early years to 11% after 1999. During follow up, 19 patients required reoperation for delayed lead dislodgement or increase in left ventricular pacing threshold (n = 15), phrenic nerve stimulation (n = 3), or infection (n = 3).CONCLUSIONS—Transverse left ventricular pacing through the coronary sinus is feasible and safe. The rate of implantation failure and of lead related problems has decreased greatly with increasing experience and with improvements in the equipment.     

双心室起搏的初步临床经验

目的 探讨缺血性或扩张型心肌病合并充血性心力衰竭行永久性双心室起搏治疗的临床效果。方法 对５例缺血性或扩张型心肌病合并难治性心力衰竭和左束支阻滞患者常规植入右心室起搏导线的同时植入冠状静脉窦导线于心大静脉或心中静脉，分别行右心室心尖部起搏及双心室起搏，应用Ｓｗａｎ－Ｇａｎｚ导管或超声心动图测定不同起搏地心功能的影响。结果 在充血性心力衰竭合并左束支阻滞患者植入冠状静脉窦导经至心大静脉或心中静脉行以     

Easy surgical approach for completion of biventricular pacing

Placement of a pacing lead into a branch of the coronary sinus for biventricular pacing sometimes is difficult or impossible. Surgical completion typically has included immediate or subsequent thoracotomy lead placement with hookup to the device at the time of chest surgery. We describe an alternative procedure of complete device-lead hookup and permanent pocket closure in the electrophysiology laboratory. The left ventricular lead is an epicardial type. The lead is tunneled to a position where the surgeon subsequently can recover it using the thoracotomy incision and implant the lead on the epicardium using device-based testing.     

Heart failure. The pacing therapy

Several medical therapies, including digoxin, angiotensin-converting enzyme inhibitors, and beta-blockers, have reduced the number of re-hospitalizations and slowed the progression of congestive heart failure (CHF) improving survival. Despite these benefits, medical therapy frequently fails to improve quality of life. Since 1990, there has been a growing interest in using cardiac pacing as additional treatment in severe CHF. Biventricular pacing is used in CHF patients with left bundle branch block (LBBB) to improve ventricular activation sequence which may lead to a more coordinated and efficient ventricular contraction. Since its introduction in CHF in 1994, biventricular pacing has been widely applied with many clinical trials and the development of new specific technology. With the development of new technology, the left ventricular catheterization via a coronary sinus vein, increased from 56% to over 95% during the last 2 years with an acceptable number of complications. Despite encouraging acute and short-term results, pacing strategies for CHF are still limited and currently regarded as investigational. It is clear that while some patients respond remarkably, this is high variable. Clinical trials are currently underway to assess the impact of cardiac resynchronization therapy on morbi-mortality and to assess the association with ventricular defibrillation. The whole validation process of cardiac resynchronization therapy should be completed on 2004-2005. Another novel mode of pacing therapy, which may be clinically appropriate for a broader range of CHF patients irrespective of the presence of LBBB, is contractility modulation, which involves sub-threshold pacing to increase intracellular calcium and enhance inotropy.     

Cardiac resynchronization pacing therapy

Approximately one third of patients with congestive heart failure and systolic dysfunction have an intraventricular conduction delay that is manifested as a QRS duration >120 ms. An intraventricular conduction delay adversely affects ventricular performance by causing dyssynchrony in ventricular activation. When ventricular dyssynchrony is present, simultaneous left and right ventricular pacing or cardiac resynchronization therapy can improve ventricular synchrony. This can lead to an improvement in hemodynamics, ventricular remodeling, mitral regurgitation, exercise capacity and quality of life. Candidates for cardiac resynchronization therapy include patients with advanced congestive heart failure that is refractory to medical therapy, a QRS duration >130 ms, left ventricular ejection fraction <0.35 and sinus rhythm. Because patients who are candidates for biventricular pacing are at high risk of sudden death, they should be considered for implantation of a biventricular pacing device that also provides defibrillation therapy. This paper reviews biventricular pacing for congestive heart failure, including results of acute hemodynamic studies and randomized clinical trials, patient and device selection, and procedural issues.     

Assessment of regional wall motion using strain Doppler imaging during right ventricular bifocal pacing in a patient with severe congestive heart failure: a case report

A 79-year-old man presented with dilated cardiomyopathy and chronic atrial fibrillation. A DDD pacemaker was implanted due to sick sinus syndrome. His left ventricular ejection fraction was 23%. He was repeatedly admitted with congestive heart failure. Although cardiac resynchronization therapy was attempted, insertion of a pacing lead into the coronary sinus failed. Right ventricular bifocal pacing was done. The QRS width was shortened to 155 msec during bifocal pacing and 157 msec during right ventricular outflow pacing from 221 msec during right ventricular apical pacing. Heart failure was improved from New York Heart Association class III to II. Regional wall motion was assessed by strain of the myocardium. Bifocal pacing increased stroke volume due to improvement of longitudinal dyssynchrony of the septal and lateral walls. Bifocal pacing is effective for patients with severe congestive heart failure in whom biventricular pacing therapy has failed. Strain Doppler imaging is useful for the assessment of regional wall motion during cardiac pacing.     

Adverse events with transvenous left ventricular pacing in patients with severe heart failure: early experience from a single centre.

AIMS: Assessment of complications following implantation of transvenous ventricular electrodes to pace the left ventricle. METHODS AND RESULTS: Twenty-eight patients with severe cardiac failure and left bundle branch block were prospectively followed for adverse effects of implantation of a left ventricular transvenous pacing system. Immediate follow-up was associated with loss of left ventricular pacing in nine patients (32%). This was due to lead dislodgement in four cases (corrected by re-operation in three of these cases), and due to increased threshold in five cases (corrected by programming a higher pacing amplitude in all five cases, but with intermittent diaphragmatic contraction in one case). After 1 month, one patient died, one patient with severe coronary heart disease suffered a myocardial infarction, and left ventricular pacing was lost in two patients. Pericardial effusion, new significant ventricular arrhythmias or other adverse effects were not observed. After a mean follow-up of 16 +/- 9.2 months, pacing leads remained stable and no late complications related to the transvenous left ventricular epicardial pacing were observed. CONCLUSION: Placement of a permanent lead in a tributary of the coronary sinus is feasible without serious adverse effects during the first month. The only frequent adverse event was lead dislodgement; a finding which emphasizes the need for development of specially designed leads for this application.     

Erfahrungen mit einer neuen transvenösen Sonde zur linksventrikulären Stimulation

BACKGROUND: Left ventricular and biventricular pacing has recently been introduced as a new therapy for chronic heart failure in selected patients. We report our initial experience with a new electrode for transvenous left epicardial pacing via tributaries of the coronary sinus. PATIENTS AND METHOD: Inclusion criteria were: chronic heart failure NYHA > or = II, QRS-duration > 120 ms, left ventricular ejection fraction < 35%. Dual chamber pacemakers (CPI Contak TR) or defibrillators (CPI Contak CD) designed for atrial triggered biventricular stimulation were implanted in conjunction with the CPI Easytrak-lead for left ventricular pacing in a coronary vein. Lead placement was achieved via a subclavian vein access and a preformed guiding catheter for coronary sinus insertion. RESULTS: In 13 of 16 patients (81%) the left ventricular lead was implanted successfully in a mid to distal posterior or anterolateral vein. Lead insertion could not be achieved in 2 patients with significant cardiomegaly and right atrial enlargement (12.5%), while 1 patient with a history of myocardial infarction and small anterior ventricular aneurysm had inacceptable high left ventricular pacing thresholds intraoperatively. The implantation was well tolerated by all patients without complications. There was no case of lead dysfunction (mean follow-up time: 142 +/- 126 days). Intraoperative electrode measurements and chronic parameters (> or = 3 months, n = 8) are given in Table 1. CONCLUSION: In the past left ventricular pacing has mainly been achieved by epicardially placed electrodes after thoracotomy with conventional electrodes. This new approach for chronic left ventricular pacing uses the familiar transvenous over-the-wire technique in combination with a newly developed guiding catheter and electrode for pacing in left epicardial veins. Lead placement was shown to be safe and success rate was higher than in previous reports with standard electrodes. We conclude that left epicardial lead placement with the over-the-wire technique and a preformed guiding catheter for coronary sinus access presents as a safe and maybe more efficient method for left ventricular pacing.     

双心室起搏的临床疗效观察

目的　探讨缺血性或扩张型心肌病合并充血性心力衰竭行永久性双心室起搏治疗的临床效果。方法　对 1 0例缺血性或扩张型心肌病合并难治性心力衰竭和左束支阻滞患者 ,常规植入右心室起搏导线的同时植入冠状静脉窦电极导线于左室侧静脉、心大或心中静脉 ,行双心室同步起搏 (其中 2例为四腔起搏 )。通过临床观察、超声心动图测定及 6分钟平地行走评定对心功能的影响。结果　在充血性心力衰竭合并左束支阻滞患者植入冠状静脉窦电极导线行双心室起搏 ,产生较窄 QRS波 ,临床心功能从 ～ 级提高至 ～ 级 ( NYHA) ,同时使二尖瓣返流减少 ,射血分数提高 ,左室舒张末期内径缩小 ,6分钟平地行走距离比术前明显提高。结论　双心室起搏对难治性心力衰竭可能有辅助治疗作用。     

2187导线在左心室起搏中的应用价值

目的寻找左心室电极导线的导入途经和技术要点及其在双心室起搏中的临床实用价值.方法 9例病人,男性8例,均为药物治疗无效合并CLBBB的顽固性心力衰竭.CS造影7例采用逆行法,2例采用顺行法显示CS.选择可剥脱CS导引导管和左室电极导线(Medtronic,2187),采用左锁骨下静脉穿刺法,经CS将电极导线置于CS左心室属支,起搏左心室.结果无论是逆行还是顺行冠状动脉造影,均清晰显示CS及其属支静脉.6例病人经导引导管将2187导线成功导入靶静脉,3例病人直接导入2187导线.电极导线尖端1例插进心大静脉远端,2例位于左室侧缘静脉,2例放在左室后静脉, 4例导入左室后侧静脉.导线到位后测量的各起搏参数均符合起搏要求,长期随访未见导线脱位和起搏功能的变化.结论 CS顺行和逆行造影均可清晰显示CS及其属支;直接或经导引导管皆可将2187电极导线导入靶静脉;应用2187型LV电极导线经CS左心室心外膜起搏技术可行、安全可靠,可广泛临床应用.     

双心室起搏对慢性心力衰竭患者心肺功能和生活质量的影响

目的:观察双心室起搏对慢性心力衰竭患者心肺功能和生活质量的影响。方法:慢性心力衰竭伴室内传导阻滞患者9例,植入三腔双心室起搏器,比较双心室起搏前、后患者超声心动图检查、心肺功能和生活质量的变化。结果:双心室同步起搏后.患者左室射血分数(%)由术前(21.6±6.7)%增加到(27.3±5.2)%(术后3月,P< 0.05)。(29.5±5.4)%(术后6月,P<0.05);6 min步行距离,由术前(320±97)m增加到(384±103)m(术后3月.P<0.01).(413±110)m(术后6月.P<0.01);峰值氧耗量、氧通气当量(VE/VO2)、二氧化碳通气当量(VE/VCO2)较术前均有显著增加(P<0.05～<0.01);生活质量评分分别改善30%(术后3月,P<0.01),28% (术后6月,P<0.01)。结论:双心室起搏能有效改善慢性心衰患者心肺功能,增加运动贮量,提高生活质量。     

Patient selection for biventricular pacing

In heart failure patients with a large QRS width, biventricular pacing has been shown to improve the fonctional status as well as hemodynamic parameters. However, there are non-responders despite of wide QRS complexes (between 15 and 35%). Patients selection might not rely only on electrical parameters. From an electrophysiological concept, clinicians moved toward a more electromechanical analysis, by using non-invasive tools such as Tissue Doppler imaging. Thereby, more than the QRS width, identification of intra-left ventricular asynchrony appears to be a crucial criterion for selecting responders to biventricular pacing. From this fact, several studies have demonstrated the efficacy of biventricular pacing to improve heart failure patients with narrow QRS but with intra-left ventricular asynchrony. Another parameter has been thought to be predominant, i.e. the left ventricular pacing site. If the pacing lead is located within a "slow conduction" area (at this time very difficult to identify during the implant procedure), biventricular pacing will generate a new asynchrony counteracting the beneficial expected. Thus, biventricular pacing appears to be more an electromechanical concept than exclusively electrical for selecting responders. Still, the optimal location of the left ventricular pacing lead remains to be determined.     

Short and long-term single-centre experience with an S-shaped unipolar lead for left ventricular pacing.

Left ventricular-based pacing is an established method for treatment of congestive heart failure in patients with ventricular dyssynchrony. The transvenous epicardial approach is the method of choice to pace the left ventricle. AIMS: To evaluate short and long-term stability and pacing and sensing performance of an S-shaped non-steroid unipolar lead. METHODS: Forty-eight procedures were performed in 43 consecutive patients (mean age: 70+/-8 years, 32 males) with severe congestive heart failure. The left ventricular lead was placed into a coronary sinus tributary. Pacing and sensing thresholds and pacing impedance were measured at implant, 1 and 6 months. RESULTS: The mean procedure time was 90.0+/-35.5 min. Pacing thresholds at implant, 1 and 6 months were 1.1+/-0.8 V, 1.9+/-1.3 V and 1.9+/-1.5 V respectively. In 7 patients, lead implantation was unsuccessful. One of them had a successful second attempt. Lead revision was performed in 5 patients for loss of capture. CONCLUSION: The S-shaped unipolar lead evaluated in this study provides stable long-term position and pacing thresholds. Recent improvement of this S-shaped lead model will hopefully reduce the rate of implantation failures and acute dislodgements.     

Persistent left-sided superior vena cava--a pacing challenge

A left sided superior vena cava (LSVC) occurs in 0.3% of the population. LSVC normally drains into the right atrium through a dilated coronary sinus. We illustrate two cases of dual chamber permanent pacemaker implantation by using (1) left subclavian vein in a 35-year-old woman with symptomatic Mobitz type II atrioventricular block; and (2) right subclavian vein in a 64-year-old man who was hospitalized with bradycardia, complete heart block, and alternating bundle branch block. After accessing the subclavian vein, the pacing leads were advanced into the LSVC, which was situated to the left of the vertebral column in the mediastinum. The leads followed the course of the LSVC medially before entering into the right atrium. Once inside the right atrium, the ventricular lead made a U-turn towards the tricuspid valve and into the right ventricle by shaping the stylet, and it was helped by right atrial contraction. An active fixation atrial lead was used in both cases to secure a satisfactory location within the right atrium. A small volume of contrast can be injected into the pacing sheath to visualize the coronary sinus opening into the right atrium, and the right ventricle. Fluoroscopy in oblique views can be helpful in guiding the atrial lead into the anteriorly positioned atrial appendage. In emergency transvenous ventricular temporary pacing where the subclavian or internal jugular vein is used, it is important to recognize the presence of a LSVC. The lead should first be directed into the right atrium and then looped back into the right ventricle. Excessive force must be avoided to prevent cardiac perforation and tamponade. If this is not successful, access through a femoral vein should be attempted.     

The response to overdrive pacing of triggered atrial and ventricular arrhythmias in the canine heart

Although triggered activity has been identified in isolated atrial tissue with the use of cellular electrophysiologic techniques, there has been no identification of triggered atrial arrhythmias in situ. Moreover, it is unclear whether triggered rhythms of different causes and sites of origin in the heart exhibit uniform responses to pacing that might aid in their identification. We therefore studied arrhythmias induced by overdrive pacing in three canine preparations, and based the analysis of our results on guidelines derived from microelectrode studies. We studied ventricular tachycardias induced by ouabain or by anterior wall myocardial infarction and atrial (coronary sinus) arrhythmias induced by the infusion of epinephrine into the great cardiac vein. In the ouabain and postinfarction preparations, right ventricular epicardial pacing induced ventricular premature beats or tachycardias whose recovery intervals after cessation of pacing shortened and showed overdrive acceleration as pacing rate increased. The first postpacing beat displayed progressive fusion with the paced beats but transient entrainment could not be induced. In the coronary sinus, the recovery intervals of impulses induced by epinephrine and pacing decreased as the drive rate increased, and inducibility of the paced rhythms increased at faster drive rates. Thus, the recovery intervals of triggered activity induced in the coronary sinus are phenomenologically similar to those of infarct- and digitalis-induced triggered rhythms. This is the first demonstration of consistent behavior in response to pacing of diverse types of triggered activity. Considered in light of the failure to induce transient entrainment, the results emphasize the potential utility of pacing in clinical identification of triggered rhythms and their differentiation from reentry.     

Coronary sinus spasm during left ventricular lead implantation for biventricular pacing.

The authors present a case of coronary sinus spasm during left ventricular lead implantation for biventricular pacing relieved by direct infusion of nitroglycerin.