Overview
ICD implantation is mechanically similar to a pacemaker implant, but the stakes and the lead are different. The RV lead is a defibrillation lead with one or two shock coils, and the generator is a larger high-voltage device. The technique is unforgiving with respect to lead placement and pocket hygiene — infection or lead failure in an ICD is a much bigger problem than in a pacemaker.
Indications
- Primary prevention: ischemic or non-ischemic cardiomyopathy with LVEF ≤35% on optimized GDMT for at least 3 months (or 40 days post-MI / 90 days post-revascularization)
- Secondary prevention: cardiac arrest from VF or hemodynamically significant VT not due to a reversible cause
- Inherited arrhythmia syndromes — long QT, HCM, ARVC, Brugada — with risk stratification favoring ICD
- Sustained VT with structural heart disease
Pre-procedure prep
- LVEF documented within 90 days and optimal GDMT documented for primary prevention
- Confirm chamber strategy: single-chamber for most primary prevention, dual-chamber if pacing indication coexists, CRT-D if QRS ≥150 ms with LBBB and LVEF ≤35%
- Hold DOACs per institutional protocol; warfarin uninterrupted is acceptable with INR 2.0–2.5
- Cefazolin 2 g IV (vancomycin if MRSA-positive) within 60 minutes of incision
- Anesthesia: moderate sedation is the default; reserve general for anticipated DFT testing or anxious patients
- Pads placed anterior-posterior for backup external defibrillation
Sterile setup
- Left chest is the default — defibrillation vector is more favorable
- Wide chlorhexidine prep including the axilla; full drying time
- Antibiotic envelope (e.g., absorbable) opened on the field for most implants
- Two suction setups; have shock cable from the programmer ready if testing
Equipment
- 9 Fr peel-away sheaths (×2 if dual-chamber, +1 if CRT-D)
- Single- or dual-coil defibrillation lead, active fixation
- RA pacing lead if dual-chamber
- ICD generator (single, dual, or CRT-D)
- Pacing system analyzer with shock cable
- External defibrillator with sterile internal/external pads
- Electrocautery, fascial retractors, suture sleeves
- Fluoroscopy with PA, LAO 40°, RAO 30°
- Antibiotic pocket irrigation (vancomycin or bacitracin saline)
Technique
- Local anesthesia + sedation; confirm a working IV on the contralateral side.
- Skin incision 2 inches below the clavicle, parallel to the deltopectoral groove.
- Pocket dissection down to pectoral fascia. Pocket should be slightly larger than the generator to avoid pressure necrosis.
- Venous access via axillary puncture (preferred) or cephalic cutdown. Two punctures if dual-chamber.
- RV defibrillation lead advanced first. Cross the tricuspid valve with a curved stylet. Target the mid-septum, not the apex. Confirm septal orientation in LAO 40° — lead points away from the sternum and toward the spine.
- Fixate with 8–10 turns of the helix under fluoro. Watch for current-of-injury pattern on the EGM.
- PSA testing of the RV lead:
- R-wave >5 mV (>7 ideal)
- Pacing threshold <1.0 V at 0.5 ms
- Pacing impedance 400–1200 ohms
- Shock impedance 30–80 ohms when measured
- RA lead placed in the appendage if dual-chamber; same targets as a pacemaker implant.
- Anchor leads with suture sleeves. Generous slack in the SVC.
- Connect to generator, torque all set-screws, verify with the wrench-back maneuver.
- DFT testing is selective — perform if there is concern about a high defibrillation threshold (right-sided implant, very low EF with structural heart disease, certain congenital anatomy). Otherwise, skip.
- Closure in layers: fascia (2-0 Vicryl), subcutaneous (3-0 Vicryl), skin (4-0 Monocryl + glue).
- Final fluoro documenting lead position before breaking sterility.
Threshold and impedance targets
- R-wave: >5 mV (>7 ideal)
- RV pacing threshold: <1.0 V at 0.5 ms
- Pacing impedance: 400–1200 ohms
- Shock impedance: 30–80 ohms
Complications
- Pocket hematoma — especially on DOAC or uninterrupted warfarin
- Pneumothorax (~1%) from venous access
- Cardiac perforation, especially with apical RV lead placement
- Inappropriate shocks — most often from AF with rapid conduction or T-wave oversensing
- Lead dislodgement in first 30 days
- Infection — devastating in an ICD, often requires extraction
Post-procedure orders
- CXR PA and lateral immediately post-procedure
- Telemetry overnight; sling for 24 hours, no overhead motion for 4–6 weeks
- ICD interrogation the morning after with full programming review
- Initial programming defaults:
- VT zone: 170–200 bpm with prolonged detection (30/40 intervals or 12 seconds)
- VF zone: >200 bpm with ATP during charging
- SVT discriminators ON
- Wound check at 7–10 days; first device clinic at 2–6 weeks
- Patient education on driving restrictions per state law and ICD shock action plan