Abstract
Background
Left bundle branch area pacing (LBBAP) is increasingly adopted for transvenous pacing. We report intraluminal lead entry into the main left anterior descending (LAD) coronary artery after deployment of an LBBAP lead.
Case Summary
An 83-year old woman with tachy-brady syndrome underwent LBBAP with an Abbott UltiPace 58cm active fixation lead. The procedure was complicated by acute chest pain with associated ST-segment elevation in the anteroseptal leads. An attempt to retract the conduction system pacing lead helix was made; however, it could not be retracted entirely. An invasive coronary angiogram demonstrated TIMI flow grade 0 in the distal LAD coronary artery vessel. After a consensus decision, she was managed conservatively; her angina and ST-segment elevation resolved. She was discharged on day 3 postimplantation with stable lead parameters.
Discussion
This case demonstrates the potential risk of intraluminal lead entry into the main LAD coronary artery after deployment of a conduction system pacing lead.
Key words: complications, conduction system pacing, coronary artery
Visual Summary
History of Presentation
We report a case of intraluminal lead entry into the left anterior descending (LAD) coronary artery after deployment of a conduction system pacing (CSP) lead. An 83-year-old woman was referred for elective implantation of a dual-chamber permanent pacemaker for a pace-and-ablate strategy for tachy-brady syndrome.
Past Medical History
Her medical history was significant for paroxysmal atrial fibrillation, hypertension, interstitial lung disease, and anxiety/depression. Her regular medications included apixaban 2.5 mg twice daily, diltiazem modified-release 240 mg daily, moxonidine 200 μg twice daily, rosuvastatin 10 mg daily, and sertraline 100 mg daily. She was independent in her activities of daily of living and a nonsmoker.
Investigations
Her baseline electrocardiogram (ECG) showed sinus rhythm with a normal PR interval and narrow QRS duration.
Management
The procedure was performed under light sedation and local anesthesia. Her apixaban had been withheld for 24 hours before the procedure. A left-sided deltopectoral incision was made and axillary vein access obtained. An Abbott CSP medium curve sheath with a standard J wire was used to position against the right ventricular septum with a contrast septogram to confirm the position. An Abbott UltiPace 58cm active fixation lead was implanted into the septum, aiming for the left bundle branch area under fluoroscopic guidance in the right anterior oblique and left anterior oblique (LAO) views with an initial contrast injection to determine septum orientation and sheath direction (Video 1, Video 2, Video 3). After deployment of the CSP lead, the patient developed chest pain, and the ECG demonstrated ST-segment elevation in the anteroseptal leads (Figure 1). A transthoracic echocardiogram demonstrated akinesis of the distal anteroseptum with a preserved left ventricular (LV) ejection fraction (visual estimate 55%-60%) but no pericardial effusion (Video 4). A brief initial attempt to retract the CSP lead helix was made; however, it could not be retracted entirely. An ECG of the paced rhythm is shown in Figure 2. Unipolar lead impedance was stable at 650 Ω with a capture threshold of 1.5 V at 0.4 ms. An atrial lead was implanted with both leads connected to the generator and the pocket closed.
Figure 1.
Electrocardiogram Showing Anteroseptal ST-Segment Elevation After Conduction System Pacing Lead Deployment
Figure 2.
Electrocardiogram of the Paced QRS Morphology at the Point of Lead Deployment
Outcome and Follow-Up
An invasive coronary angiogram via the right radial approach was performed immediately after, which demonstrated TIMI flow grade 0 in the distal LAD coronary artery from the CSP lead (Figure 3; Videos 5 and 6). Given her clinical stability, a consensus decision, in conjunction with the interventional cardiology team, was made to conservatively manage her. Her troponin peaked at 28,869 ng/L, and her chest pain resolved after 2 days. Her device check on day 1 postimplantation showed stable lead parameters (threshold 1.25 V @ 0.4 ms for the CSP lead). She was discharged on day 3 postprocedure, with no further angina, resolution of ST-segment elevation, and recommencement of apixaban. At 1-month clinic follow-up, her lead parameters remained stable and she remained free of angina. Her echocardiogram at 3-month follow-up showed persistent apical septal hypokinesis but preserved LV systolic function with no evidence of LV thrombus.
Figure 3.
S-T Segment Elevation in the Anteroseptal Leads on ECG During Lead Deployment
(A) Anterior-posterior (AP) view of the Abbott UltiPace 58cm active fixation lead with the Abbott CSP (conduction system pacing) medium curve sheath. (B) Left anterior oblique view of the leads after deployment. (C) Right anterior oblique–cranial view of the coronary angiogram showing lead deployment into the distal left anterior descending coronary artery with TIMI flow grade 0 distally.
Discussion
CSP, and specifically left bundle branch area pacing (LBBAP), has been increasingly adopted globally as a potential alternative to conventional cardiac resynchronization therapy with a coronary sinus branch lead or even upfront in patients with normal left ventricular systolic function but an anticipated high ventricular pacing burden to reduce the risk of pacing-induced cardiomyopathy.1, 2, 3 There are several different leads that have been specifically developed or repurposed for CSP, including both stylet-driven and lumenless leads.4,5 Yet their implantation is not without potential procedural risks, including coronary artery injury. Several case reports have reported injury to the septal branch arising from the LAD coronary artery during deployment (Table 1).6, 7, 8, 9 Our case illustrates an example of direct intraluminal lead entry into the main distal LAD coronary artery with resultant anteroseptal myocardial infarction. This occurred despite confirming the septal position of the delivery sheath at the 2 o'clock position in the LAO view with a contrast injection.10 Radiographic LAO and right anterior oblique views need to be individualized for each patient according to their anatomy, previous cardiac surgery, and structural abnormalities, such as ventricular dilatation.
Table 1.
Case Reports Regarding Coronary Artery Injury From Conduction System Pacing Leads
| First Author | Patient | Lead | Clinical Presentation | Lead Complication | Outcome |
|---|---|---|---|---|---|
| Ponnusamy and Vijayaraman6 | 65 y, female | Medtronic SelectSecure 3830 | Aborted STEMI. Peak troponin I 0.23 ng/mL | Possible coronary vasospasm from trauma to the septal arterial branch from the LAD coronary artery | Lead retracted and repositioned in the apical location. No further complications with no RWMA on TTE |
| Ferrari et al9 | 70 y, female | Biotronik Solia S60 | Chest discomfort on day 1 postprocedure. Peak high-sensitivity troponin 2,686 ng/L | Septal coronary artery fistula from the septal artery to the right ventricular septum | Small fistula, minor shunt volume, and clinically stable. Managed conservatively |
| Ferrari et al9 | 69 y, female | Abbott Tendril 2088 | Cough and shortness of breath. Troponin T 9,000 μg/mL | Extrinsic compression of the LAD coronary artery by the lead helix | Backup septal lead inserted and then the original lead repositioned to the RV outflow septal position. Improvement in HF symptoms and EF noted |
EF = ejection fraction; HF = heart failure; LAD = left anterior descending; RV = right ventricle; RWMA = regional wall motion abnormality; STEMI = ST-segment elevation myocardial infarction; TTE = transthoracic echocardiogram.
Our anecdotal experience with the stylet-driven Abbott UltiPace 58cm active fixation lead using the Abbott sheath delivery system is its rapid deployment through the septum with only several clockwise rotations relative to other CSP lead delivery systems (eg, Biotronik Solia S60 or Medtronic SelectSecure 3830 lead). Proceduralists must be cautious with regard to either perforation through the septal side of the LV myocardium or proximity to the LAD coronary artery and its associated septal branches. Monitoring of conventional CSP parameters, including progress toward negative current of injury during unipolar pacing, unipolar impedance <500 Ω, or a drop of >200 Ω, unipolar pacing by a ring electrode to assess lead ring contact with the interventricular septum, and paced QRS morphology, remains crucial.10 Of note, the paced QRS complex showed significant fractionation, which is usually indicative of myocardial scar but could also reflect localized coronary injury in this context. Furthermore, if there is clinical concern for injury to the LAD coronary artery or its septal branches, there should be thoughtful consideration of whether the lead should be retracted in conjunction with the interventional cardiology team. Indeed, a published case reported active bleeding from a ruptured septal branch of the LAD coronary artery after LBBAP, which led to cardiac arrest and subsequent mechanical extracorporeal membrane support, pericardial drain, and intracoronary vascular coils to salvage the patient.8 Although in a separate case the lead could be retracted after septal branch injury, leading to an aborted ST-segment elevation myocardial infarction,6 it is possible that coronary artery injury could be worsened after helix retraction with subsequent perforation.
The echocardiogram showed apical septal hypokinesis at the time of her lead deployment and infarct due to injury to the LAD coronary artery because of intraluminal lead deployment. Interventricular septal hematomas have been reported from damage to septal perforator arteries.11,12 The artery, its branches, and its distribution would dictate whether regional hypokinesis or akinesis would be observed. Given the lead deployment to the main mid- to distal LAD coronary artery and associated septal branches in this case, the distribution was consistent with a regional wall motion abnormality affecting the distal apex and septum. This would not be a significantly different appearance had it been a primary ischemic occlusive event of the distal LAD coronary artery from acute coronary syndrome.
The timing of direct oral anticoagulant recommencement in the context of lead-associated LAD coronary artery injury needs to be balanced with the risk of worsening coronary artery injury and pocket bleeding. The clinical decision to withhold anticoagulation for 3 days postoperatively was made in view of the risk of pericardial effusion/tamponade with coronary artery perforation. Nevertheless, the standard practice at our center is to withhold the direct oral anticoagulant on the day before the device procedure and recommence the following day for most patients with AF. Guidelines currently recommend a periprocedural anticoagulation plan according to the operator’s preference.13 Given that the patient did not have any coronary intervention (eg, metallic stent) and had already occluded her mid-LAD coronary artery at this point, the decision was made not to commence additional antiplatelet therapy.
Visual Summary.
Left Anterior Descending Coronary Artery Injury During Left Bundle Branch Area Pacing Lead Deployment
Conclusions
Although LBBAP is becoming increasingly performed worldwide, it is important for proceduralists to recognize potential complications with this technique, including coronary artery injury, and in this case intraluminal lead entry, and ways to mitigate this risk.
Patient Consent
The patient verbally consented to the publication of her medical case in a peer-reviewed medical journal. The authors of this paper, who actively participated in the decision process and management, obtained written informed consent from the patient in accordance with COPE guidelines.
Funding Support and Author Disclosures
Dr Healy serves on the medical advisory boards of Biotronik and Boston Scientific. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
Take-Home Messages
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Intraluminal coronary artery injury is a potential complication of left bundle branch area pacing lead deployment.
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Close monitoring of conduction system pacing parameters and fluoroscopic guidance is important to mitigate this risk, while prompt recognition of potential coronary artery injury is crucial.
Footnotes
The authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the Author Center.
Appendix
For supplemental videos, please see the online version of this paper.
Appendix
Initial Contrast Injection Through the Delivery Sheath to Confirm Perpendicular Orientation to the Interventricular Septum in the LAO (35°) View
Deployment of the Conduction System Pacing Lead With the Delivery Sheath in the LAO View
Deployment of the Conduction System Pacing Lead With the Delivery Sheath in the RAO View
Four-Chamber Apical Transthoracic Echocardiogram View Demonstrating Akinesis of the Distal Anteroseptum After Conduction System Pacing Lead Deployment
Coronary Angiogram View (RAO 30°, Cranial 30°) Demonstrating TIMI Flow Grade 0 in the Distal Left Anterior Descending Coronary Artery
Coronary Angiogram View (LAO 25°, Cranial 35°) Demonstrating TIMI Flow Grade 0 in the Distal Left Anterior Descending Coronary Artery
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
Initial Contrast Injection Through the Delivery Sheath to Confirm Perpendicular Orientation to the Interventricular Septum in the LAO (35°) View
Deployment of the Conduction System Pacing Lead With the Delivery Sheath in the LAO View
Deployment of the Conduction System Pacing Lead With the Delivery Sheath in the RAO View
Four-Chamber Apical Transthoracic Echocardiogram View Demonstrating Akinesis of the Distal Anteroseptum After Conduction System Pacing Lead Deployment
Coronary Angiogram View (RAO 30°, Cranial 30°) Demonstrating TIMI Flow Grade 0 in the Distal Left Anterior Descending Coronary Artery
Coronary Angiogram View (LAO 25°, Cranial 35°) Demonstrating TIMI Flow Grade 0 in the Distal Left Anterior Descending Coronary Artery