A Method for Permanent Transvenous Left Ventricular Pacing

LV-based pacing has recently been reported to be of benefit in patients with severe cardiac failure and left bundle branch block. LV permanent pacing has been reported using epicardial leads but the surgical mortality is excessive. A transvenous approach is now favored. In this regard, cannulation of the coronary sinus and of one of its tributaries using only the permanent electrode is feasible but technically challenging. We describe a "long guiding sheath" method using catheterization, and a long radiopaque and peelable sheath. Once the coronaiy sinus is cannulated with the electrophysiological catheter, the long sheath is advanced to the mid-part of the coronary sinus. The permanent pacing electrode is then placed through the sheath and into a tributary of the coronary sinus. This method has been attempted in 10 patients and was successful in 8, with an average lead insertion time of 21 ± 5.5 minutes and an average fluoroscopic time of 11 ± 5.5 minutes. In conclusion, although transvenous left ventricular pacing remains a challenge, the "long guiding sheath" approach appears to facilitate this procedure with both a high success rate and an acceptable procedure time.     

Seven Years of Left Ventricular Pacing Due to Malposition of Pacing Electrode

The case report is presented of a patient in whom an uncomplicated left ventricular transvenous pacing produced right bundle branch block (RBBB). A diagnostic echocardiography, confirmed by cine cardiovascular computed tomography, showed that there was no rupture of the right ventricle and diagnosed a left ventricular pacing, due to malposition of the pacing electrode. The patient was treated with aspirin and dipyridamole during the last 6 years of follow-up, without any complications, including 1 year of pacing, prior to admission.     

Left Atrial Size and Wall Motion in Patients with Permanent Ventricular and Atrial Pacing

KUBICA, J., ET AL.: Left Atrial Size and Wall Motion in Patients with Permanent Ventricular and Atrial Pacing. It is well known that during permanent ventricular pacing atrial arrhythmias and embolic complications occur much more frequently in comparison to permanent atrial or sequential pacing. He-modynamic disturbances caused by ventriculoatrial conduction (VAC) are thought to be responsible for those complications. The aim of this study was to compare the left atrial size and its wall motion in three groups of patients with sick sinus syndrome. Group 1: 58 patients with VVI pacing and VAC observed (22 males, 36 females, aged 31–86, mean 62.3). Group 2: 43 patients with primary AAI pacing (13 males, 30 females, aged 27–74, mean 57.8). Group 3: 13 patients with AAI or DDD replacing the primary VVI mode due to pacemaker syndrome and/or heart failure, all with VAC present during VVI pacing (7 males, 6 females, aged 26–80, mean 59.8). Two-dimensional/M-mode echocardiography was performed in all these patients. In group 1 mean diastolic as well as mean systolic atrial diameters were significantly greater (p < 0.005) and wall motion significantly smaller (p < 0.005) in comparison to the other groups. Left atrial wall motion amounted to only 7.4% of the mean diastolic diameter in this group. Mean left atrial diastolic and systolic diameters and wall motion in patients with pacemakers preserving atrioventricular synchrony (group 2 and group 3) were almost identical and wall motion amounted to about 22% of the diastolic diameter in both these groups. We conclude that ventriculoatrial conduction leads to significant enlargement of left atrium and to the atrial wall-motion decrease. This predisposes to arrhythmias and embolic complications. Changes in atrial size and performance seem to be reversible with restoration of the physiological atrioventricular synchrony.     

Long-Term Experience with a Preshaped Left Ventricular Pacing Lead

OLLITRAULT, J., et al. : Long-Term Experience with a Preshaped Left Ventricular Pacing Lead. This study describes a long-term experience with a new LV pacing lead. The study population consisted of 62 patients (85% men,   71 ± 10   years old) with advanced dilated cardiomyopathy, in NYHA Class III or IV despite optimal drug therapy, and a QRS duration >150 ms. Patients in sinus rhythm were implanted with a triple chamber pacemaker to maintain atrioventricular synchrony. A dual chamber pacemaker was implanted in patients in atrial fibrillation for biventricular pacing only. A clinical evaluation and interrogation of the resynchronization pacemaker were performed at implant, at 1 week (W1), one (M1), four (M4), and seven (M7) months after implantation. A longer follow-up (2 years) is available for patients implanted at the authors institution. LV measurements were pacing threshold at 0.5-ms pulse duration and pacing impedance. R wave amplitude (mV) was measured at the time of implantation only. The system was successfully implanted in 86% of patients with the latest design of the lead. Mean R wave amplitude at implant was   15 ± 7 mV   and mean pacing impedance was   1054 ± 254 Ω   . Between implant   (n = 38)   and M7   (n = 15)   , pacing threshold rose from   0.73 ± 0.54   to   1.57 ± 0.60 V (P < 0.001)   . In conclusion, the situs lead was successfully implanted in a high percentage of patients. In addition, low pacing threshold and high impedance measured during follow-up are consistent with a low pacing current drain, ensuring a durable pulse generator longevity. (PACE 2003; 26[Pt. II]:185–188)     

Electrocardiographic Patterns during Left Ventricular Epicardial Pacing

Background: There is a paucity of data concerning the use of QRS morphology patterns for identifying pacing sites during left ventricle (LV)‐only epicardial pacing in patients with a biventricular device. The objective of this study was to identify QRS patterns during LV‐only pacing, and to establish their relationship with LV lead position. In addition, to validate the diagnostic performance of such electrocardiogram (ECG) patterns for predicting posterolateral versus anterior and apical versus nonapical LV pacing site. Methods: The study retrospectively analyzed data from 376 cardiac resynchronization therapy device patients. Data analyzed included ECGs registered during LV‐only VVI pacing, fluoroscopic projections, and lateral chest roentgenograms that documented postimplantation LV lead position. Phase one of the study involved categorization of the ECG patterns of the first 66 study cases. Phase two of the study examined the association between ECG pattern and different LV lead positions. Results: As the LV epicardial pacing site became more anteroapical, the LV‐only paced QRS complexes in the precordial leads became more negative. Three ECG patterns were identified (posterolateral, intermediate, and anteroapical), and their distribution was found to be associated with LV lead position (P < 0.001). The posterolateral ECG pattern was mostly observed in cases where the LV lead was in the posterolateral area (diagnostic accuracy of 89.1% for predicting a nonapical LV lead position). The anteroapical ECG pattern was associated with LV leads in anteroapical segments (specificity of 98.5%, accuracy of 89.1% for predicting an anteroapical pacing site). Conclusions: Posterolateral and anteroapical ECG patterns are highly predictive of LV lead position. (PACE 2012; 35:1361–1368)     

Left Ventricular Pressure Measurement During Noninvasive Transcutaneous Cardiac Pacing

In a pacemaker-dependent patient, the hemodynamic response during external transcutaneous and endocardial sequential pacing was evaluated by left ventricular pressure monitoring. A single ventricular pacing mode with hemodynamic effect of atrioventricular asynchrony was shown during external pacing.     

Inadvertent Left Ventricular Pacing through the Pericardium

Inadvertent placement of a pacemaker lead in the left ventricle (LV) is a rare complication of pacing. We describe a case of inadvertent LV pacing where the ventricular lead traversed the mediastinum and accessed the heart through the posterior wall of the left atrium. Both transesophageal echo and venography were useful in understanding the course of the misplaced lead, which was removed percutaneously without complication.     

Balloon‐Facilitated Delivery of a Left Ventricular Pacing Lead

While modern implant tools have contributed greatly to the success of cardiac resynchronization therapy, technical challenges remain. A common problem is the inability to advance left ventricular pacing leads into branch veins that are tortuous or arise at steep angles. In these cases, advancement of the lead causes it to buckle and prolapse into the coronary sinus or great cardiac vein. Lead prolapsed can be avoided by employing a balloon to temporarily obstruct the coronary sinus or great cardiac vein just upstream from the branch vein. The balloon redirects the force of advancement laterally into the branch vein, facilitating delivery. (PACE 2013; 36:e31–e34)     

Early Results of AV Sequential Pacing on Left Ventricular Outflow Obstruction after Senning Procedure

Dual chamber pacing was shown to decrease left ventricular outflow tract (LVOT) obstruction in patients with hypertrophic cardiomyopathy 30 years ago. We report early results of AV sequential pacing from the LV apex in a patient with transposition of the great arteries who is post-Senning procedure. LVOT obstruction resulted from septal deviation and systolic anterior motion of the mitral valve. Pacing was indicated for sinus node dysfunction. AV sequential pacing with a short optimal A V interval of 60 ms demonstrated a 45% reduction in the degree of LVOT obstruction. This article suggests that LVOT obstruction after the Senning procedure can be palliated by asynchronous septal contraction induced by A V sequential pacing, even if the activation is from LV apex, and avoid or postpone surgery in selected situations.     

Single Site Left Ventricular Pacing induced Dyssynchrony and Cardiomyopathy

Single site left ventricular (LV) pacing in the absence of intrinsic ventricular activity can be as detrimental to LV function as right ventricular apical pacing. This report describes a patient with complete heart block who developed significant dyssynchrony and cardiomyopathy secondary to single site lateral LV pacing. The process was reversed by placement of a second anterior LV lead. (PACE 2013; 36:e35–e37)     

Permanent Left Atrial Pacing with a Specifically Designed Coronary Sinus Lead

This article reports the original use of a specifically designed coronary sinus (CS) lead for permanent left atrial (LA) pacing. The device is characterized by its distal end shape featuring a double 45° angulation. which ensures very close contact with the CS upper wall. The device was successfully implanted in 39 out of 40 patients (97.5%). The tip electrode was eventually positioned in the distal CS in 9 patients, in the middle CS in 21 patients, and close to the ostium in the proximal CS in 9 patients. The mean acute pacing threshold voltage was 0.9 ± 0.5 V with a mean impedance of 578 ± 144 Ω as measured in unipolar distal configuration at 0.5 ms pulse width (PW). The mean A wave amplitude was 3.5 ± 2.1 mV. Early lead dislodgment occurred only once (3%) when the tip electrode was placed in the distal or middle CS, but more often (4/9 cases) when it was placed in the proximal CS. After a mean follow-up duration of 14 ± 8.5 months, 35 of the 39 successfully implanted leads (89.7%) were still functional in terms of LA pacing and sensing. The mean chronic pacing threshold voltage was 1.5 ± 0.8 V and the mean A wave amplitude was 2.7 ± 1.6 mV. There were no lead related complications. In conclusion, the device proved to be safe and highly effective for permanent LA pacing, provided the distal tip could be positioned in the distal or middle part of the CS.     

Abolition of Diaphragmatic Pacing by Nonsurgical Retraction of a Left Ventricular Lead

This report describes the nonsurgical elimination of intractable diaphragmatic stimulation by partial withdrawal of a left ventricular (LV) pacing lead (in the coronary venous system) with resultant preservation of LV pacing. The procedure entailed the use of a deflectable catheter in the right atrium for ensnaring the LV lead. At the 3-month follow-up, the absence of diaphragmatic stimulation was associated with a satisfactory LV pacing threshold and dramatic clinical improvement from effectual biventricular pacing.     

Transvenous Left Atrial and Left Ventricular Pacing in Ebstein's Anomaly with Severe Interatrial Conduction Block

The implantation of permanent pacemakers in patients with congenital heart disease can be challenging. This report describes the complexity of pacemaker implantation in a patient with Ebstein's disease, tricuspid valve replacement, and right atrial abnormalities like severe intra- and interatrial conduction block that prevented dual chamber pacing from conventional sites. This case illustrates the promising possibility to circumvent the interatrial conduction block with single left atrial pacing instead of biatrial pacing which was not suitable here.     

Long-term Stability of Endocardial Left Ventricular Pacing Leads Placed via the Coronary Sinus

Background: Left ventricular endocardial pacing leads placed via the coronary sinus (CS) are increasingly implanted to achieve cardiac resynchronization therapy (CRT); however, the long-term stability of these leads is unknown. We sought to determine the implant success and long-term stability of CS leads in our single center experience.
Methods: All consecutive patients who underwent CRT via implantation of the CS lead between January 1999 and December 2005 were included. Pacing thresholds at implant and during long-term follow-up were reviewed and the rate of acute (within 24 hours of implant) and chronic (>24 hours) lead failure was determined.
Results: A total of 512 patients (mean age 68 ± 12 years; 409 [80%] male) underwent CRT device implantation and were included. The CS lead implantation was successful on the initial implantation in 487 patients (95%) and subsequently successful in six patients (24%) in whom initial attempts were unsuccessful. Acute lead failure occurred in 25 patients (5.1%) and was most commonly due to persistent extra-cardiac stimulation. The rate of chronic lead failure was 4% in the first year and remained stable during long-term follow-up. The CS lead pacing thresholds remained stable with only minimal increase (1.42 ± 0.85 V/0.42 ± 0.25 ms vs 1.51 ± 1.05 V/0.47 ± 0.29 ms; P = 0.04).
Conclusions: Placement of a left ventricular pacing lead via the CS is feasible and safe in the vast majority of patients. Once placed, the CS leads remain stable with excellent pacing thresholds over the longer term.     

不同起搏方式对左心室重构的近远期影响

目的 评价不同起搏模式植入后对左心室重构的近远期影响。 方法 通过M型、二维及多普勒超声心动图检测了24例VVI型起搏器和32例DDD型起搏器患者术前、术后1年和5年时左房内径、左室舒张和收缩末期内径、左室射血分数、左室短轴缩短分数的改变,并以植入前后的差值来比较两者在左心室结构和功能重构上的差异。 结果 随访术后1和5年时,VVI型和DDD型起搏器除左房内径均增大外,其余结构指标均好转,而左心室收缩功能的指标以DDD型好于VVI型,且两者相比较差异有显著性。 结论 DDD型心脏起搏器比VVI型在术后近远期对左心室结构和功能重构上具有更好的效果。     

Inadvertent Left Ventricle Endocardial or Uncomplicated Right Ventricular Pacing: How to Differentiate in the Emergency Department

Background

Temporary transvenous pacemaker implantation is an important and critical procedure for emergency physicians. Traditionally, temporary pacemakers are inserted by electrocardiography (ECG) guidance in the emergency department because fluoroscopy at the bedside in an unstable patient can be limited by time and equipment availability. However, in the presence of atrial septal defect, ventricular septal defect, and patent foramen ovale, the pacemaker lead can be implanted inadvertently into the left ventricle or directly into the coronary sinus instead of right ventricle. Regular pacemaker rhythm can be achieved despite inadvertent implantation of the pacemaker lead into the left ventricle, leading to ignorance of the possibility of lead malposition.

Feasibility Of Temporary Biventricular Pacing In Patients With Reduced Left Ventricular Function After Coronary Artery Bypass Grafting

Background and Methods: Biventricular pacing improves hemodynamics after weaning from cardiopulmonary bypass in patients with severely reduced left ventricular (LV) function undergoing coronary artery bypass grafting (CABG). We examined the feasibility of temporary biventricular pacing for 96 hours postoperatively. Unipolar epicardial wires were placed on the roof of the right atrium (RA), the right ventricular (RV) outflow tract, and the LV free lateral wall and connected to an external pacing device in 51 patients (mean LV ejection fraction 35 ± 4%). Pacing and sensing thresholds, lead survival and incidence of pacemaker dysfunction were determined.
Results: Atrial and RV pacing thresholds increased significantly by the 4th postoperative day, from 1.6 ± 0.2 to 2.5 ± 0.3 V at 0.5 ms (P = 0.03) at the RA, 1.4 ± 0.3 V to 2.7 ± 0.4 mV (P = 0.01) at the RV, and 1.9 ± 0.6 V to 2.9 ± 0.7 mV (P = 0.3) at the LV, while sensing thresholds decreased from 2.0 ± 0.2 to 1.7 ± 0.2 mV (P = 0.18) at the RA, 7.2 ± 0.8 to 5.1 ± 0.7 mV (P = 0.05) at the RV, and 9.4 ± 1.3 to 5.5 ± 1.1 mV (P = 0.02) at the LV. The cumulative overall incidence of lead failure was 24% by the 4th postoperative day, and was similar at the RV and LV. We observed no ventricular proarrhythmia due to pacing or temporary pacemaker malfunction.
Conclusions: Biventricular pacing after CABG using a standard external pacing system was feasible and safe.     

Short-Term and Long-Term Changes of Left Ventricular Volumes During Rate-Adaptive and Single-Rate Pacing

To evaluate the adaptation of the heart to exercise during pacing, 15 patients with permanent endocardial pacemakers were studied; nine patients had atrioventricular universal (DDD) pacemakers (Symbios 7005) and six patients had activity detecting rate-responsive ventricular (VVIR) pacemakers (Activitrax 8403). Left ventricular function in each patient during rate variable pacing was compared to ventricular function during VVI single-rate pacing. End-systolic and end-diastolic volume changes during exercise were measured by radionuclide angiography and the amount of volume change was used to assess left ventricular function. Both short-term (within 4 hours) and long-term measurements (after at least 4 weeks) were made at rest and at 50% of the maximal exercise capacity in DDD or VVIR mode and were compared with VVI single-rate pacing. All patients, when changed from DDD or VVIR mode to VVI single-rate pacing showed a significant increase of the end-diastolic volume during exercise, which increased even more after long-term VVI pacing. During long-term rate variable pacing, there was no increase of the end-diastolic volume during exercise. DDD or VVIR pacing initially showed a substantial increase of the end-systolic volume during exercise combined with a decrease of left ventricular ejection fraction, suggesting a decrease of the left ventricular contractility. After 4 weeks, contractility improved both with DDD and VVIR pacing. We conclude that short-term DDD and VVIR pacing induces a temporary impairment of left ventricular function that improves after 4 weeks, whereas long-term VVI pacing is associated with left ventricular dilatation even at moderate levels of exercise.     

实时三维超声心动图评价右室不同部位起搏对左室收缩功能及收缩同步性的影响

目的:应用实时三维超声心动图评价右室不同部位起搏对左室收缩功能及收缩同步性的影响。方法:将行双腔起搏器植入术的20例房室传导阻滞患者按起搏部位的不同分为右室心尖部起搏组(RVA组)和右室流出道起搏组(RVOT组)。两组患者均于术前及术后3个月应用二维及三维超声心动图检查左室容积、射血分数、LV区域壁运动,并比较两组患者的左室收缩功能及收缩同步性指标。结果:术后两组16节段、12节段、6节段达到最小容积时间的最大差值和标准差(Tmsv-dif,Tmsv-dif%,Tmsv-sd,Tmsv-sd%),差异无统计学意义(P0.05),但RVOT组左室收缩同步性高于RVA组(P0.05);两组常规二维超声参数及左室整体收缩功能差异无统计学意义(P0.05)。结论:短期内,右室不同部位起搏不影响左室整体收缩功能和左室收缩同步性。