What medications should be continued, adjusted, or discontinued before pacemaker implantation?

Medication Management Before Pacemaker Implantation

Continue oral anticoagulation (warfarin) throughout the pacemaker implantation procedure without interruption, as this strategy significantly reduces bleeding complications compared to heparin bridging while maintaining thromboembolic protection.

Anticoagulation Management

Warfarin/Oral Anticoagulants - CONTINUE

• Patients on chronic warfarin should continue therapy uninterrupted through the pacemaker implantation procedure 1, 2.
• Perioperative continuation of warfarin is associated with pocket hematoma rates of only 1.9-6.6%, compared to 12-20% with heparin bridging strategies 2.
• Target INR should remain therapeutic (typically 2.0-3.0) at the time of implantation 1.
• Thromboembolic event rates remain extremely low (0-1%) regardless of anticoagulation strategy, but bleeding risk is dramatically lower with continuation 2.

Heparin Bridging - AVOID

• Do not use heparin bridging (either unfractionated or low molecular weight heparin) as this markedly increases bleeding complications 3, 2, 4.
• Heparin bridging was associated with all significant bleeding complications requiring pocket exploration in one study (p<0.0001) 4.
• If bridging was previously performed, independent predictors for bleeding include thrombocytopenia (HR 6.0), congestive heart failure (HR 4.5), high thromboembolic risk (HR 6.9), and increasing CHADS₂ score (HR 2.3) 3.

Antiplatelet Agents - CONTINUE

• Continue aspirin and clopidogrel through the pacemaker implantation without interruption 4.
• Hematoma formation after pacemaker implantation is rare even in patients taking antiplatelet agents 4.
• Only 7% of implanters stop thienopyridines prior to device implantation in patients with recent drug-eluting stents, reflecting the higher risk of stent thrombosis 5.

Antiarrhythmic Medications

Medications That Depress Sinus/AV Node Function

• In patients with bradycardia-tachycardia syndrome requiring antiarrhythmic therapy, the pacemaker should be implanted BEFORE initiating or continuing drugs that suppress sinus node function 6.
• Propranolol and amiodarone severely depress sinus node function and may require pacing support in bradycardia-tachycardia syndrome 6.
• Type I antiarrhythmic drugs (quinidine) are particularly dangerous in children with bradycardia-tachycardia syndrome and should only be used after pacemaker placement 6.
• Digitalis and phenytoin are safer alternatives that may not require pacing support 6.

QT-Prolonging Medications

• For patients on quetiapine or other QT-prolonging drugs, obtain baseline ECG to measure QTc before pacemaker implantation 7.
• If QTc >500 ms, reconsider quetiapine therapy as the pacemaker does not protect against drug-induced torsades de pointes 7.
• Patients with pacemakers for bradycardia-tachycardia syndrome are particularly vulnerable to antipsychotic-induced arrhythmias 7.
• Avoid concomitant use of Class IA or Class III antiarrhythmics with QT-prolonging drugs 7.

Rate-Limiting Medications

Beta-Blockers and Calcium Channel Blockers

• Continue beta-blockers and calcium channel blockers (amlodipine) through the procedure unless the patient has symptomatic bradycardia requiring urgent pacing 8.
• For symptomatic bradycardia pre-procedure, reduce or temporarily hold rate-limiting medications while monitoring for hemodynamic improvement 8.
• If severe symptomatic bradycardia persists despite medication adjustment, proceed urgently with temporary pacing followed by permanent pacemaker implantation 8.

Critical Pitfalls to Avoid

• Never bridge with therapeutic-dose heparin - this is the single highest risk factor for pocket hematoma requiring surgical intervention 2, 4.
• Do not stop warfarin in high thromboembolic risk patients (mechanical mitral valve, recent stroke/TIA, high CHADS₂ score) as continuation is safer than bridging 3, 2.
• Do not assume the pacemaker will protect against drug-induced arrhythmias - QT-prolonging medications still carry torsades risk even with pacing 7.
• In bradycardia-tachycardia syndrome, implant the pacemaker before escalating antiarrhythmic therapy to avoid dangerous bradycardia from sinus node suppression 6.

Pre-Procedure Laboratory Assessment

• Check INR on day of procedure if on warfarin - proceed if therapeutic 1.
• Measure serum electrolytes (potassium, magnesium) particularly in patients on QT-prolonging drugs, as hypokalemia significantly increases arrhythmia risk 7.
• Assess renal function (creatinine clearance) if LMWH was previously considered, though this should be avoided 3.