Permanent pacemaker implantation in Ebstein anomaly with metallic tricuspid valve

Right ventricular endocardial pacing is partially contraindicated in the presence of mechanical tricuspid valve. Occurrences of atrioventricular block are commonly associated in postoperative period in Ebstein anomaly repaired with mechanical tricuspid valve. Coronary sinus (CS) pacing is the preferred site in this scenario. However, the anatomical variations in Ebstein anomaly leads to difficulties in hooking the CS. With the help of real time left coronary injection enabled in understanding the anatomical orientation of CS ostium take off, leading to successful CS lead implantation.

Technical feasibility of leadless left bundle branch area pacing for cardiac resynchronisation: a case series

Background Left bundle branch area pacing (LBBAP) is a novel form of conduction system pacing which can reverse left bundle branch block and deliver cardiac resynchronisation therapy (CRT). The WiSE-CRT system delivers leadless endocardial pacing with symptomatic and left ventricular (LV) remodelling improvements following intervention. We report the technical feasibility of delivering leadless LBBAP using the WiSE-CRT system. Case Summary In case 1, a 57-year-old male with ischaemic cardiomyopathy and complete heart block underwent implantation of the WiSE-CRT system, using a retrograde trans-aortic approach, after failed conventional CRT. Temporary left bundle stimulation from the LV septum achieved superior electrical resynchronisation and equivalent haemodynamic response compared to endocardial pacing at the lateral LV wall. In case 2, an 82-year-old gentleman with tachyarrhythmia-induced cardiomyopathy underwent WiSE-CRT implantation via a trans-septal intra-atrial approach, with the endocardial electrode successfully deployed in the LV septum. Discussion Here we report the first case of deployment of the WiSE-CRT endocardial electrode in the LV septum, and demonstrate the technical feasibility of leadless LBBAP. Entirely leadless CRT is an attractive option for patients with venous access issues or recurrent lead complications and has previously been successful using the WiSE-CRT system and a leadless pacemaker in the right ventricle. Further studies are required to assess long-term efficacy and safety of leadless LBBAP.

Optimal CRT Implantation—Where and How To Place the Left-Ventricular Lead?

Purpose of Review Cardiac resynchronization therapy (CRT) represents a well-established and effective non-pharmaceutical heart failure (HF) treatment in selected patients. Still, a significant number of patients remain CRT non-responders. An optimal placement of the left ventricular (LV) lead appears crucial for the intended hemodynamic and hence clinical improvement. A well-localized target area and tools that help to achieve successful lead implantation seem to be of utmost importance to reach an optimal CRT effect. Recent Findings Recent studies suggest previous multimodal imaging (CT/cMRI/ECG torso) to guide intraprocedural LV lead placement. Relevant benefit compared to empirical lead optimization is still a matter of debate. Technical improvements in leads and algorithms (e.g., multipoint pacing (MPP), adaptive algorithms) promise higher procedural success. Recently emerging alternatives for ventricular synchronization such as conduction system pacing (CSP), LV endocardial pacing, or leadless pacing challenge classical biventricular pacing. Summary This article reviews current strategies for a successful planning, implementation, and validation of the optimal CRT implantation. Pre-implant imaging modalities offer promising assistance for complex cases; empirical lead positioning and intraoperative testing remain the cornerstone in most cases and ensure a successful CRT effect.

Transvenous endocardial pacemaker pacing in thoracoscopic cardiac surgery

Background: Temporary cardiac pacing is frequently required during heart surgery due to life-threatening complications of arrhythmias. The conventional method of epicardial pacing could have risks such as bleeding and myocardial tears. Transvenous endocardial pacing provides another option. The efficiency of transvenous epicardial and endocardial pacing were compared in this study. Methods: We performed a retrospective study and reviewed medical records in patients who received either thoracoscopic cardiac surgery with transvenous endocardial pacing or median sternotomy with transvenous epicardial pacing between June 2019 and January 2021. Patients were assigned into two groups depending on the surgical type and pacing method. Preoperative patient characteristics and perioperative outcomes were collected. The efficiencies of endocardial and epicardial pacing were compared and analyzed in SPSS. Results: A total of 68 patients were included. Thirty-five (51.5%) patients were in the thoracoscopic cardiac surgery group with transvenous endocardial pacing. Thirty-three (48.5%) patients were in the median sternotomy group with transvenous epicardial pacing. Intensive care unit (ICU) time (p = 0.014), in-hospital duration (p = 0.036), operation time (p = 0.005), and the 24-h drainage volume (p < 0.001) showed significant differences between the two groups. There was no significant difference between the pre- and post-operative heart rate and rhythm compared between two groups. Conclusions: Compared with transvenous epicardial pacing, transvenous endocardial pacing showed no significant differences in heart rate and arrhythmia during the perioperative period. Transvenous endocardial pacing was also associated with better operative measurements.

Endocardial pacing is not haemodynamically superior to trans-coronary sinus epicardial pacing in cardiac resynchronization therapy: the Endo-Epi CRT study

Funding Acknowledgements Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Medtronic Background Cardiac resynchronization therapy (CRT) conventionally involves trans-coronary sinus, epicardial left ventricular (LV) pacing. Some studies have suggested that endocardial LV pacing may be superior to epicardial LV pacing. Objectives To compare the acute haemodynamic effects of CRT when delivered from endocardial (Endo-CRT) and epicardial LV stimulation sites (Epi-CRT). Methods and results Sixteen CRT recipients (aged 70.4 ± 10.1 years [mean ± SD], 62.5% male, QRS: 156.5 ± 16.1 ms, LBBB in 13 [81.3%]) in sinus rhythm underwent intra-procedural measurements of the rate of rise of LV pressure (dP/dtmax) during Endo- and Epi-CRT (RADI pressure wire). Epi-CRT was delivered in basal, mid and apical positions. The Endo-CRT pacing site was chosen using iterative, biplane fluoroscopic views, to target the same position as the Epi-CRT site on the endocardium (see Figure A). Compared to AAI pacing (10 beats per minute above intrinsic rate), both Endo-CRT and Epi-CRT led to an increase in LV dP/dtmax (6.52 ± 8.90% and 6.15 ± 7.97% respectively, both p &lt; 0.001). There were no significant differences in the change in LV dP/dtmax (ΔLV dP/dtmax) between Endo-CRT and Epi-CRT at basal (p = 0.54), mid (p = 0.78) or apical LV stimulation sites (p = 0.12) [Figure B]. Conclusions Endo-CRT is not haemodynamically superior to Epi-CRT. Abstract Figure.

Acute hemodynamic response of epicardial and endocardial cardiac resynchronization therapy, His bundle pacing and left bundle branch pacing

Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): Medtronic Background / Introduction Endocardial pacing and conduction system pacing are emerging as alternative methods to deliver cardiac resynchronization therapy (CRT) and have been shown to achieve superior acute hemodynamic response (AHR) compared to conventional epicardial pacing. However, a direct comparison of all the methods of delivering CRT has not yet been performed. Purpose To directly compare the AHR of conventional CRT (BiV Epi), endocardial pacing (BiV Endo), His bundle pacing (HBP) and left bundle branch pacing (LBBP) during a temporary CRT study. Methods 4 patients underwent a temporary CRT and hemodynamic study. Temporary pacing was achieved using quadripolar catheters in the right atrium and coronary sinus, and roving decapolar catheters in the right ventricle (RV) and left ventricle (LV) via retrograde aortic access. Hemodynamic assessment was performed with a PressureWire X (Abbott, CA, USA) in the LV cavity. AHR was calculated as the percentage improvement in LV dP/dtmax from baseline AAI or RV pacing (if underlying complete heart block). Results The patients had a mean age of 67.5 ±5.8 years and all had non-ischemic cardiomyopathy with severe LV impairment (mean ejection fraction 22.5 ±7.4%). 3 patients had left bundle branch block and 1 patient had complete heart block with an RV paced rhythm (mean QRS duration 157 ±24 ms). All methods of delivering CRT achieved a mean AHR of &gt;10%, which is considered clinically significant and is predictive of LV remodelling at 6 months. Mean AHR during BiV Epi pacing was 12.6 ±5.0%. There was a trend towards higher AHR for BiV Endo pacing (23.6 ±7.6%), HBP (17.4 ± 9.5%) and LBBP (16.1 ±7.8%) as shown in figure 1, however there was no significant difference between groups on one-way analysis of variance (p = 0.348). Conclusions All methods of delivering CRT achieved an AHR &gt;10%. The AHR during BiV Endo pacing, HBP and LBBP was higher than for BiV Epi pacing, but this did not reach statistical significance. Further investigation with larger studies is required to determine which method of delivering CRT achieves the best hemodynamic response. Figure 1. Box plot of acute hemodynamic response (AHR) for conventional cardiac resynchronization therapy (BiV Epi), endocardial pacing (BiV Endo), His bundle pacing (HBP) and left bundle branch pacing (LBBP). Data displayed as median (solid line), mean (+), 1st and 3rd quartiles (box) and minimum and maximum values (whiskers). Abstract Figure 1

Right Bundle Branch Block Morphology After Right Ventricular Endocardial Pacing – When Should a Cardiologist Begin to Worry ?

Even though the left bundle branch block (LBBB) morphology in the surface electrocardiogram (ECG) is expected after right ventricular endocardial pacing, the right bundle branch block (RBBB) morphology may be paradoxically seen in around 8 to 10% of patients. The paced RBBB morphology should be given special attention in terms of safe RV pacing or septal and free wall perforation. Simple techniques such as moving the leads V1-2 to one interspace lower than standard (Klein maneuver) and combining frontal QRS axis between -30° to -90°, precordial transition point at or within V3, and absence of S wave in lead I as an algorithmic approach may correctly identify the pacemaker lead in right ventricle with high sensitivity, specificity, and positive predictive value.

Leadless Left Ventricular Endocardial Pacing and Left Bundle Branch Area Pacing for Cardiac Resynchronisation Therapy

Cardiac resynchronisation therapy is an important intervention to reduce mortality and morbidity, but even in carefully selected patients approximately 30% fail to improve. This has led to alternative pacing approaches to improve patient outcomes. Left ventricular (LV) endocardial pacing allows pacing at site-specific locations that enable the operator to avoid myocardial scar and target areas of latest activation. Left bundle branch area pacing (LBBAP) provides a more physiological activation pattern and may allow effective cardiac resynchronisation. This article discusses LV endocardial pacing in detail, including the indications, techniques and outcomes. It discusses LBBAP, its potential benefits over His bundle pacing and procedural outcomes. Finally, it concludes with the future role of endocardial pacing and LBBAP in heart failure patients.

Potential for leadless left bundle branch pacing for cardiac resynchronization: a case report

Introduction: Left bundle branch pacing is a recently described form of conduction system pacing which can correct left-bundle branch block and deliver cardiac resynchronization therapy (CRT). The WiSE-CRT system delivers leadless endocardial pacing and can improve symptoms and left ventricular remodelling in CRT non-responders. Case Report: We describe the case of a 57 year old male who underwent implantation of the WiSE-CRT system after failed conventional CRT. Pacing the left bundle during implant achieved superior electrical resynchronization and equivalent hemodynamic response compared to pacing the lateral wall. Conclusion: This case demonstrates the potential for leadless left bundle branch pacing.