Interventional device implantation, Part I: Basic techniques to avoid complications: A hands-on approach

A novel method combining gated SPECT and vectorcardiography to guide left ventricular lead placement to improve response to cardiac resynchronization therapy: A proof of concept study

BACKGROUND

The segment of the latest mechanical contraction (LMC) does not always overlap with the site of the latest electrical activation (LEA). By integrating both mechanical and electrical dyssynchrony, this proof-of-concept study aimed to propose a new method for recommending left ventricular (LV) lead placements, with the goal of enhancing response to cardiac resynchronization therapy (CRT).

METHODS

The LMC segment was determined by single-photon emission computed tomography myocardial perfusion imaging (SPECT MPI) phase analysis. The LEA site was detected by vectorcardiogram. The recommended segments for LV lead placement were as follows: (1) the LMC viable segments that overlapped with the LEA site; (2) the LMC viable segments adjacent to the LEA site; (3) If no segment met either of the above, the LV lateral wall was recommended. The response was defined as ≥15% reduction in left ventricular end-systolic volume (LVESV) 6-months after CRT. Patients with LV lead located in the recommended site were assigned to the recommended group, and those located in the non-recommended site were assigned to the non-recommended group.

RESULTS

The cohort comprised of 76 patients, including 54 (71.1%) in the recommended group and 22 (28.9%) in the non-recommended group. Among the recommended group, 74.1% of the patients responded to CRT, while 36.4% in the non-recommended group were responders (P = .002). Compared to pacing at the non-recommended segments, pacing at the recommended segments showed an independent association with an increased response by univariate and multivariable analysis (odds ratio 5.00, 95% confidence interval 1.73-14.44, P = .003; odds ratio 7.33, 95% confidence interval 1.53-35.14, P = .013). Kaplan-Meier curves showed that pacing at the recommended LV lead position demonstrated a better long-term prognosis.

CONCLUSION

Our findings indicate that pacing at the recommended segments, by integrating of mechanical and electrical dyssynchrony, is significantly associated with an improved CRT response and better long-term prognosis.

Is interventional technique better than the traditional over-the-wire method for left ventricular lead implantation in cardiac resynchronization therapy?

Background

Interventional cardiac resynchronization therapy (I-CRT) for left ventricular lead (LVL) placement works as a supplement to traditional (over-the-wire) cardiac resynchronization therapy (T-CRT). It has been argued that I-CRT is a time-consuming and complicated procedure.

Objective

The purpose of this study was to investigate differences in procedure-related, perioperative, postoperative, and clinical endpoints between I-CRT and T-CRT.

Methods

This single-center, retrospective, cohort study included all consecutive patients receiving a CRT-pacemaker/defibrillator between January 1, 2012, and August 31, 2018. Patients underwent T-CRT from January 1, 2012, to June 1, 2015, and I-CRT from January 1, 2016, to August 31, 2018. We obtained data from patient record files, fluoroscopic images, and the Danish Pacemaker and ICD Register. Data were analyzed using Wilcoxon rank-sum/linear regression for continuous variables and the Pearson χ2/Fisher exact for categorical variables.

Results

Optimal LVL placement was achieved in 82.7% of the I-CRT group and 76.8% of the T-CRT group (P = .015). In the I-CRT group, 99.0% of LVLs were quadripolar vs 55.3% in the T-CRT group (P <.001). Two or more leads were used during the procedure in 0.7% and 10.5% of all cases in the I-CRT and T-CRT groups, respectively (P <.001). Total implantation time was 81.0 minutes in the I-CRT group and 83.0 minutes in the T-CRT group (P = .41). Time with catheters in the coronary sinus was 45.0 minutes for the I-CRT group vs 37.0 minutes in the T-CRT group, respectively (P <.001).

Conclusion

I-CRT did not prolong total implantation time despite longer time with catheters in the coronary sinus. I-CRT allowed more optimal LVL placement, wider use of quadripolar leads, and use of fewer leads during the procedure.

Left bundle branch area pacing too far away from the tricuspid annulus may cause pacing induced cardiomyopathy

BACKGROUND

Physiologic pacing through left bundle branch area pacing (LBBAP) has recently been shown to be a very promising alternative for cardiac resynchronization therapy (CRT) and to avoid pacing induced cardiomyopathy. However, it is not clear whether the position of LABBP lead may affect the clinical outcomes.

CASE REPORT

We here report a case of likely LBBAP induced worsening heart failure and cardiomyopathy reversed by re-positioning of the pacing lead towards a more annular position. A 70-year-old male with a previous history of non-ischemic dilated cardiomyopathy (ejection fraction 40%) who developed intermittent complete heart block and required permanent ventricular pacing. LBBAP was performed with the lead positioned to a position relatively far away from the tricuspid annulus (3.7 cm), due to difficulty in fixating the lead deep into the septum at a more annular position. One month post procedure, the patient's heart failure symptoms worsened, and his EF decreased to 31% despite good heart failure management. He underwent CRT upgrade with successful revision of the originally implanted LBBAP lead to a more annular position, using a deflectable delivery sheath. This resulted in further narrowing of the paced QRS duration from 135 to 106 ms. Two months post procedure, his heart failure symptoms improved by one functional class, and EF improved to 41% by echocardiogram.

CONCLUSIONS

LBBAP may be harmful when the lead is placed too far away from the annulus and may cause paced induced cardiomyopathy.

The long-term safety and effectiveness of the loop technique in left ventricular lead dislocation

Objectives

Cardiac resynchronization therapy (CRT) is a well-established method that improves the clinical symptoms and long-term prognosis of specific heart failure (HF) patients by restoring systolic synchronicity and enhancing myocardial function. However, the high rate of intraoperative and postoperative left ventricular (LV) lead dislocation limits its application to a great extent. The aim of this study was to demonstrate the long-term safety and effectiveness of a new approach named the loop technique for patients who experience repeated intraoperative transvenous LV lead dislocations during CRT.

Methods

The current study was a single-centre, prospective, nonrandomized controlled trial. Forty-four HF patients who underwent CRT were included. All patients were followed to death or 3 years.

Results

Among 44 HF patients, 36 underwent the traditional operation, and 8 underwent the loop technique due to repeated intraoperative LV lead dislocations. Intergroup comparison revealed no significant differences between the two groups with respect to most preoperative indices, intraoperative pacing and sensing parameters. At the end of the 3-year follow-up, 4 (11.1%) patients in the traditional operation group and 2 (25.0%) patients in the loop technique group had died. There was no significant difference in the mortality rate (P = 0.30). No complications related to this new technique were observed, such as intracoronary thrombosis, infection or dislocation. Intergroup comparison showed no significant difference in the New York Heart Association (NYHA) class, echocardiography indices, N-terminal pro brain natriuretic peptide (NT-proBNP) level or pacemaker programming parameters.

Conclusions

The loop technique is a safe and effective alternative method for patients who experience repeated intraoperative transvenous LV lead dislocations during CRT.

Initial Experience in Transvenous Implantation of a Left Ventricular Lead With a Novel Venogram Balloon Catheter

Aim

The most challenging and time-consuming stage of cardiac resynchronization therapy (CRT) device implantation is coronary sinus (CS) cannulation and left ventricular epicardial electrode implantation. This paper reports the initial clinical experience of CS cannulation and left ventricular lead implantation guided by a novel venogram balloon catheter (Lee's venogram balloon catheter).

Methods and Results

Consecutive patients eligible for CRT were deemed suitable for this novel venogram balloon catheter. Parameters such as left ventricular lead implantation time, procedure time, and fluoroscopy time were recorded. CS cannulation with LV lead implantation guided by Lee's venogram balloon catheter was successful in all 5 patients, including 4 challenging cases. The total fluoroscopy and procedural durations were 5.0 ± 3.0 and 57.4 ± 12.5 min, respectively. No adverse catheter-related events occurred during the procedures.

Conclusion

This initial study of an innovative venogram balloon catheter demonstrated that it greatly facilitated CS cannulation and successful LV lead placement in all patients undergoing CRT system implantation. This significantly shortened the learning curve and showed a decrease in left ventricular lead implantation time, procedure time, and fluoroscopy time.

A Mild Dyssynchronous Contraction Pattern Detected by SPECT Myocardial Perfusion Imaging Predicts Super-Response to Cardiac Resynchronization Therapy

Background

Using single photon emission computed tomography myocardial perfusion imaging (SPECT MPI) with phase analysis (PA), we aimed to identify the predictive value of a new contraction pattern in cardiac resynchronization therapy (CRT) response.

Methods

Left ventricular mechanical dyssynchrony (LVMD) was evaluated using SPECT MPI with PA in non-ischemic dilated cardiomyopathy (DCM) patients with left bundle branch block (LBBB) indicated for CRT. CRT super-response was defined as LV ejection fraction (EF) ≥50% or an absolute increase of LVEF >15%. The LV contraction was categorized as the mild dyssynchronous pattern when the phase standard deviation (PSD) ≤ 40.3° and phase histogram bandwidth (PBW) ≤ 111.9°, otherwise it was defined as severe dyssynchronous pattern which was further characterized as U-shaped, heterogeneous or homogenous pattern.

Results

The final cohort comprised 74 patients, including 32 (43.2%) in mild dyssynchronous group, 17 (23%) in U-shaped group, 19 (25.7%) in heterogeneous group, and 6 (8.1%) in homogenous group. The mild dyssynchronous group had lower PSD and PBW than U-shaped, heterogeneous, and homogenous groups (P < 0.0001). Compared to patients with the heterogeneous pattern, the odds ratios (ORs) with 95% confidence intervals (CIs) for CRT super-response were 10.182(2.43–42.663), 12.8(2.545–64.372), and 2.667(0.327–21.773) for patients with mild dyssynchronous, U-shaped, and homogenous pattern, respectively. After multivariable adjustment, mild dyssynchronous group remained associated with increased CRT super-response (adjusted OR 5.709, 95% CI 1.152–28.293). Kaplan-Meier curves showed that mild dyssynchronous group demonstrated a better long-term prognosis.

Conclusions

The mild dyssynchronous pattern in patients with DCM is associated with an increased CRT super-response and better long-term prognosis.

Troubleshooting the difficult left ventricular lead placement in cardiac resynchronization therapy: current status and future perspectives

INTRODUCTION

Cardiac resynchronization therapy (CRT) is an important option in modern cardiac implantable electronic device (CIED) treatment. Techniques for left ventricular (LV) lead placement in the coronary sinus and its tributaries are neither well described nor studied systematically, despite attention regarding where to place the LV lead.

AREAS COVERED

This review presents specialized tools and techniques to overcome some of the most common problems encountered in LV lead placement in CRT. These tools and techniques are termed Interventional-CRT (I-CRT), as they share technology with other interventional procedures. The main principle in I-CRT, compared to the traditional Over-The-Wire technique, is to add better support for delivery of the LV lead through dedicated inner catheters that also allows more flexibility with use of more guidewires and better imaging with direct venography in the target vein.

EXPERT OPINION

Even though CRT is an established therapeutic option, there are still many challenges in the implementation of the therapy. The cornerstone should be an ease of delivering the CRT and specifically implantation of the LV lead. Therefore, knowledge of the principles in I-CRT, as I-CRT could make implantation simpler in general and easier to reach the optimal LV pacing site.

A case report of balloon-assisted tracking to overcome coronary sinus competent valve: a novel technique in left ventricular lead implantation

Background

Competent lateral and posterolateral valves showed proximal tortuosity that might hinder left ventricular (LV) lead implantation in cardiac resynchronization therapy (CRT).

Case summary

A 57-year-old woman was diagnosed as non-ischaemic cardiomyopathy, no other comorbidities, complaining of dyspnoea [New York Heart Association (NYHA) class III], and on optimal medical therapy. Electrocardiogram showed left bundle branch block with QRS duration 150 ms. The patient was candidate for CRT. However, during LV lead implantation, a competent posterolateral vein valve and proximal tortuosity hindered LV lead implantation that was overcome by balloon-assisted tracking technique. At 9 months of follow-up, the patient had NYHA class II, ejection fraction improved to 38%, and all implanted leads were still in place.

Discussion

Balloon-assisted tracking technique can be used to cross coronary sinus and smaller veins with competent valves and coronary veins tortuosity.

Optimization of cardiac resynchronization therapy based on a cardiac electromechanics-perfusion computational model

Cardiac resynchronization therapy (CRT) is an established treatment for left bundle branch block (LBBB) resulting in mechanical dyssynchrony. Approximately 1/3 of patients with CRT, however, are non-responders. To understand factors affecting CRT response, an electromechanics-perfusion computational model based on animal-specific left ventricular (LV) geometry and coronary vascular networks located in the septum and LV free wall is developed. The model considers contractility-flow and preload-activation time relationships, and is calibrated to simultaneously match the experimental measurements in terms of the LV pressure, volume waveforms and total coronary flow in the left anterior descending and left circumflex territories from 2 swine models under right atrium and right ventricular pacing. The model is then applied to investigate the responses of CRT indexed by peak LV pressure and (dP/dt)max at multiple pacing sites with different degrees of perfusion in the LV free wall. Without the presence of ischemia, the model predicts that basal-lateral endocardial region is the optimal pacing site that can best improve (dP/dt)max by 20%, and is associated with the shortest activation time. In the presence of ischemia, a non-ischemic region becomes the optimal pacing site when coronary flow in the ischemic region fell below 30% of its original value. Pacing at the ischemic region produces little response at that perfusion level. The optimal pacing site is associated with one that optimizes the LV activation time. These findings suggest that CRT response is affected by both pacing site and coronary perfusion, which may have clinical implication in improving CRT responder rates.

Azygous Vein Coil Implantation in Left Ventricular Assist Device Patients: A Hands-on Approach

Recently, there have been reports of left ventricular assist device (LVAD) patients presenting with multiple ineffective implantable cardioverter-defibrillator (ICD) shocks. In such patients, the placement of an azygous vein coil by providing an alternative anteroposterior trajectory of the electrical shock vector can enable successful defibrillation. This review discusses a hands-on approach to azygous vein coil implantation. Additionally, we compare our tools and technique to those that have been previously described by other operators. From 2018 to 2021, eight patients were identified who underwent azygous vein coil implantation at MedStar Washington Hospital Center using a specific technique and tools. Demographic and procedural data were obtained by a retrospective review of patient charts, procedure logs, fluoroscopy, and venography performed during coil implantation. The indication for azygous vein coil implantation was ineffective ICD shocks in seven patients. The presenting rhythm was ventricular fibrillation in six (75%) cases and sustained ventricular tachycardia in two (25%) cases. Using the approach described, we were able to successfully implant an azygous vein coil in all eight (100%) patients. There were no procedure-related complications. Postimplantation, defibrillation threshold (DFT) testing was successfully performed in six of eight (75%) patients. One patient failed DFT testing despite placement of an azygous vein coil. In another patient, DFT testing was not performed because the patient was in atrial fibrillation and was not systemically anticoagulated. In conclusion, the placement of an azygous vein coil in LVAD patients with failed ICD shocks using the tools and technique described in this report is safe and highly efficacious (successful in 100% of cases).

"Retained wire femoral lead removal and fibroplasty" for obtaining venous access in patients with refractory venous obstruction

BACKGROUND

Patients with wire and catheter refractory venous occlusion are traditionally referred for pectoral transvenous lead extraction (TLE) to obtain venous access. TLE causes 1-2 mm circumferential mechanical or laser destruction of tissue surrounding the lead(s). This not only exposes the patient to the risk of major complications but also can damage nontargeted leads. We present a series of patients where retained wire femoral lead removal and fibroplasty was used to obtain venous access in patients with refractory obstruction.

METHODS

Between 2008 and 2021, we identified 17 patients where retained wire lead removal followed by fibroplasty was used to retain venous access. Demographic and procedural data were obtained by retrospective review of patient charts.

RESULTS

We were able to successfully obtain venous access in all 17 patients in whom this technique was attempted. In two patients the target lead was less than or equal to 1 year old. In the remaining 15 patients, the average dwell time of the target lead(s) was 6 years. There were no procedure-related complications, and no changes in the parameters of other leads were noted.

CONCLUSION

Retained wire femoral lead removal and fibroplasty is safe and highly efficacious at obtaining venous access in patients with refractory venous occlusion. If the target lead(s) is less than or equal to 1 year old, this technique can help obtain venous access at the time of the initial surgery, hence avoiding the need for TLE. Furthermore, in patients referred for TLE to obtain venous access, this technique by avoiding the use of TLE tools spares the patient of the associated risks.

The combination of coronary sinus ostial atresia/abnormalities and a small persistent left superior vena cava-Opportunity for left ventricular lead implantation and unrecognized source of thromboembolic stroke

BACKGROUND

Coronary sinus (CS) ostial atresia/abnormalities prevent access to the CS from the right atrium (RA) for left ventricular (LV) lead implantation. Some patients with CS ostial abnormalities also have a small persistent left superior vena cava (sPLSVC).

OBJECTIVE

The purpose of this study was to describe CS ostial abnormalities and sPLSVC as an opportunity for LV lead implantation and unrecognized source of stroke.

METHODS

Twenty patients with CS ostial abnormalities and sPLSVC were identified. Clinical information, imaging methods, LV lead implantation techniques, and complications were summarized.

RESULTS

Forty percent had at least 1 previously unsuccessful LV lead placement. In 70%, sPLSVC was identified by catheter manipulation and contrast injection in the left brachiocephalic vein, and in 30% by levophase CS venography. In 30%, sPLSVC was associated with drainage from the CS into the left atrium (LA). When associated with CS ostial abnormalities, the sPLSVC diameter averaged 5.6 ± 3 mm. sPLSVC was used for successful LV lead implantation in 90% of cases. In 80%, the LV lead was implanted down sPLSVC, and in 20%, sPLSVC was used to access the CS from the RA. Presumably because of unrecognized drainage from the CS to the LA, 1 patient had a stroke during implantation via sPLSVC.

CONCLUSION

When CS ostial abnormalities prevent access to the CS from the RA, sPLSVC can be used to successfully implant LV leads. In some, the CS partially drains into the LA and stroke can occur spontaneously or during lead intervention. It is important to distinguish sPLSVC associated with CS ostial abnormalities from isolated PLSVC.

Interventional device implantation, Part I: Basic techniques to avoid complications: A hands-on approach

Introduction

The essence of cardiac resynchronization therapy (CRT) is biventricular (BiV) pacing, which involves implanting pacing leads in both the right ventricle (RV) and left ventricle (LV). Unlike traditional RV pacing, many hurdles lie ahead of successful LV lead implantation.

Methods and Results

In this review, we first highlight the importance of optimizing the patient and the tools. Next, we describe the CRT tools developed over several decades, to facilitate successful implantation. Thereafter, we provide a streamlined step‐by‐step summary of the basic BiV implantation procedure. Lastly, we discuss some commonly encountered challenges during implantation and the techniques to tackle them.

Conclusion

A systematic approach to every step of the implantation process can reduce procedure time, decrease patient exposure to radiation and contrast, and minimize complications. The use of right tools and techniques can enable all implanters to become more successful with BiV implantation.