What are the steps of pacemaker implantation in a patient with a history of cardiac conditions?

Pacemaker Implantation Procedure: Detailed Steps

Pre-Procedure Patient Assessment

Before beginning implantation, establish the indication for pacing through focused evaluation of the patient's cardiac history and underlying rhythm disorder. 1

Critical Pre-Implant Determinations

• Document the specific indication: Complete heart block with symptomatic bradycardia, second-degree AV block type II, post-AV nodal ablation, or other qualifying arrhythmia 1
• Assess pacemaker dependency risk: Patients with history of symptomatic bradyarrhythmia, successful AV nodal ablation, or inadequate escape rhythm (<40 bpm) are pacemaker-dependent 1
• Determine optimal pacing mode: VVI for permanent atrial fibrillation with no atrial contribution; DDD for complete heart block with intact sinus node function; VVIR/DDDR for chronotropic incompetence with anticipated moderate-to-high activity levels 1, 2
• Review chest x-ray and ECG to assess cardiac anatomy and baseline rhythm 1

Sedation and Anesthesia Protocol

Conscious sedation with local anesthesia is the standard approach for pacemaker implantation, providing adequate patient comfort while maintaining protective reflexes. 3

• Administer intravenous midazolam for anxiolysis and amnesia, combined with fentanyl for analgesia during incisional discomfort 3
• Infiltrate local anesthetic (typically lidocaine 1-2%) at the incision site and along the subcutaneous pocket dissection plane 3
• Avoid deep sedation or general anesthesia unless specifically required, as conscious sedation minimizes recovery time and allows same-day discharge for some procedures 3

Venous Access and Lead Placement

The cephalic vein cutdown or subclavian vein puncture provides access to the venous system for transvenous lead advancement to the right heart chambers. 4, 5

Lead Insertion Technique

• Prepare the infraclavicular region (typically left side unless contraindicated) with sterile technique 4, 5
• Create a 4-6 cm incision in the deltopectoral groove, approximately 2 cm below the clavicle 4
• Isolate the cephalic vein through careful dissection, or perform subclavian vein puncture using anatomic landmarks or ultrasound guidance 4
• Introduce the pacing lead(s) through the venous access: single lead for VVI/VVIR systems, dual leads for DDD/DDDR systems 1
• Advance the ventricular lead under fluoroscopic guidance to the right ventricular apex or septum, ensuring stable position with adequate R-wave amplitude (>5 mV) and low pacing threshold (<1.0 V at 0.5 ms) 4
• Position the atrial lead (if dual-chamber system) in the right atrial appendage with adequate P-wave sensing (>2 mV) and low atrial pacing threshold 1

Lead Fixation Verification

• Test lead stability by having the patient cough and take deep breaths while monitoring electrical parameters 4
• Secure active-fixation leads by deploying the helical screw into the myocardium 4
• Confirm passive-fixation leads are wedged securely in trabeculated myocardium 4

Generator Pocket Creation and Connection

Create a subcutaneous or submuscular pocket in the pectoral region to house the pulse generator, ensuring adequate tissue coverage to prevent erosion. 4, 5

• Dissect a pocket between the pectoralis major muscle and subcutaneous tissue, sized appropriately for the generator without excessive dead space 4
• Achieve meticulous hemostasis to prevent pocket hematoma formation 4
• Connect the lead(s) to the pulse generator using the manufacturer's connection system, ensuring secure attachment 4
• Program initial settings based on the predetermined pacing mode: lower rate limit typically 60 bpm for VVI, AV delay 150-200 ms for DDD systems 1, 2
• Test pacing capture and sensing at various outputs to confirm proper function 4

Wound Closure and Post-Implant Verification

Close the incision in layers after confirming proper device function, then obtain chest x-ray and ECG to document lead position and pacing function. 1, 4

• Anchor the leads to the pectoral fascia using non-absorbable sutures to prevent lead migration 4
• Place the generator in the pocket with leads forming gentle curves without acute angles 4
• Close the pocket in layers: deep fascia, subcutaneous tissue, and skin 4
• Obtain immediate post-procedure chest x-ray (PA and lateral views) to confirm lead position and rule out pneumothorax 1
• Record 12-lead ECG showing paced rhythm to establish baseline 1
• Interrogate the device to document final programmed parameters, battery status, and electrical measurements 1, 4

Critical Intraoperative Monitoring

Continuous ECG monitoring and peripheral pulse assessment are mandatory throughout the procedure to detect lead malposition or loss of capture. 1

• Monitor both electrical capture (wide QRS complexes following pacing spikes) and mechanical capture (palpable pulse, arterial waveform) 6
• Have temporary pacing and defibrillation equipment immediately available in case of device malfunction or ventricular arrhythmia 1
• Position electrocautery grounding pad so current pathway does not pass through the device system 1
• Use short, intermittent electrocautery bursts at lowest feasible energy to minimize electromagnetic interference 1

Common Pitfalls to Avoid

• Never implant an atrial lead in permanent atrial fibrillation without rhythm control plans, as this provides no benefit and increases procedural complexity (Class III: Harm) 2
• Avoid VVI pacing in patients with pacemaker syndrome risk: those with congestive heart failure requiring maximum atrial contribution, or those who developed symptoms during temporary ventricular pacing 1
• Do not use VVIR mode in patients with retrograde ventriculoatrial conduction, as rapid pacing can precipitate pacemaker syndrome 1, 2
• Ensure adequate lower rate programming (typically ≥60 bpm) to prevent symptomatic bradycardia, particularly in complete heart block 1, 2
• Verify pacemaker-dependent patients (complete heart block, post-AV ablation, no escape rhythm) have backup temporary pacing available throughout the procedure 1, 7