How should bradycardia be managed in a patient scheduled for elective surgery?

Management of Bradycardia in Elective Surgery

For patients at high risk of intraoperative bradycardia during elective noncardiac surgery, place transcutaneous pacing pads prophylactically rather than performing routine transvenous pacing, and be prepared with atropine and resuscitation equipment immediately available. 1

Preoperative Risk Assessment

Identify high-risk patients using clinical predictors before proceeding to elective surgery:

• Age >60-65 years 1
• Baseline heart rate <60 bpm 1, 2
• Baseline blood pressure <110/60 mm Hg 1, 2
• ASA Class III or IV comorbidities 1
• Current use of beta-blockers, ACE inhibitors, or ARBs 1, 2
• Revised cardiac risk index ≥3 points 2
• Major surgery planned 2

The HEART score (Heart rate <60, hypotension <110/60, Elderly >65, renin-Angiotensin blockade, Revised cardiac risk index ≥3, Type of major surgery) predicts intraoperative bradycardia/hypotension with moderate accuracy (C-statistic 0.75, likelihood ratio +3.64 at maximum points). 2

Prophylactic Measures for Noncardiac Surgery

Place transcutaneous pacing pads on patients identified as high-risk before induction—this is a Class IIa recommendation with moderate-quality evidence. 1

Do NOT perform routine prophylactic transvenous pacing in patients with LBBB requiring pulmonary artery catheterization—this is a Class III (Harm) recommendation, as the risk of complete heart block is low (though clinicians should be prepared with immediate transcutaneous or transvenous pacing capability if needed). 1

Procedure-Specific Considerations

Certain procedures carry inherently higher bradycardia risk:

• Carotid endarterectomy/stenting: Associated with vagal-mediated bradycardia; transcutaneous pacing was effective in eliminating bradycardia in all 23/30 patients who required it during carotid angioplasty. 1
• Laparoscopic surgery: Rapid peritoneal insufflation causes vagal-mediated bradycardia from peritoneal stretching; use low CO2 flow rates to minimize risk. 1, 3
• Ophthalmic surgery: Manipulation of trigeminal nerve-innervated regions can trigger bradycardia. 1
• Spinal anesthesia: Can cause sudden severe bradycardia/asystole at unpredictable intervals (10-70 minutes post-block) regardless of sensory level. 4

Intraoperative Management

When bradycardia develops intraoperatively:

1. Stop the precipitating stimulus (e.g., halt peritoneal insufflation, cease surgical manipulation). 3

2. Administer atropine 0.5-2 mg IV as first-line therapy for hemodynamically significant bradycardia. 1, 5, 3, 6, 4

   • Doses <0.5 mg may paradoxically worsen bradycardia due to bimodal sinoatrial node response. 1
   • Atropine is ineffective in heart transplant patients (causes paradoxical heart block in 20%). 1

3. Initiate transcutaneous pacing immediately if atropine fails, particularly in patients with latent sick sinus syndrome or severe bradycardia (<45 bpm). 3, 6, 4

4. Consider glycopyrrolate 0.1 mg IV (repeated at 2-3 minute intervals as needed) as an alternative anticholinergic, particularly for intraoperative use. 5

5. Prepare for ACLS protocol including CPR if severe bradycardia progresses toward cardiac arrest. 3, 4

Cardiac Surgery-Specific Management

For elective cardiac surgery, management differs substantially:

• Routine placement of temporary epicardial pacing wires is recommended (Class I for aortic/tricuspid valve surgery, Class IIa for CABG/mitral valve surgery). 1

• Permanent pacemaker before discharge is indicated (Class I) if new postoperative sick sinus node dysfunction or AV block causes persistent symptoms/hemodynamic instability that doesn't resolve within 5-7 days. 1

Critical Pitfalls to Avoid

• Never rely solely on conduction disorders (e.g., LBBB) to justify prophylactic transvenous pacing—routine placement of transcutaneous pads provides adequate backup without the increased risk of ventricular arrhythmias associated with temporary transvenous pacing. 1

• Intraoperative bradycardia during noncardiac surgery is predominantly due to sick sinus node dysfunction, not worsening AV conduction. 1

• Vecuronium carries higher risk of severe/symptomatic bradycardia requiring treatment compared to atracurium in gynecological surgery. 7

• Spinal anesthesia-related bradycardia/asystole can occur without warning signs (except occasional nausea seconds before) and is not reliably predicted by sensory block level. 4