Why do all cardiothoracic and vascular surgery (CTVS) patients have pacing wires?

Why Cardiothoracic Surgery Patients Routinely Receive Temporary Epicardial Pacing Wires

Temporary epicardial pacing wires are routinely placed in all cardiothoracic surgery patients because bradyarrhythmias requiring pacing occur unpredictably in 0.8-24% of cases postoperatively, and the small risk of wire-related complications is outweighed by the frequent need for emergent rate support or atrioventricular synchrony. 1

Standard Surgical Practice and Rationale

• Temporary epicardial pacing wires are suture-sized wires placed on the atrial and/or ventricular epicardium at the end of cardiac surgery, with the proximal end brought out through the skin for connection to an external pacemaker generator. 1

• The ACC/AHA/HRS guidelines give a Class IIa recommendation (reasonable) for routine placement of temporary epicardial pacing wires during isolated coronary artery bypass surgery, aortic valve surgery, and mitral valve surgery. 1

• For surgery addressing atrial fibrillation, routine placement receives a Class I recommendation (should be performed), reflecting the higher risk of postoperative conduction abnormalities in this population. 1

Unpredictable Need for Postoperative Pacing

The fundamental reason for universal placement is the inability to reliably predict which patients will require pacing:

• The need for temporary pacing after cardiac surgery varies widely from 0.8% to 24%, depending on the type of surgery and patient risk factors. 1

• In isolated coronary artery bypass grafting, 8.6% of patients require postoperative pacing, but even in the lowest-risk subgroup (no diabetes, no preoperative arrhythmia, no pacing needed during bypass separation), 2.6% still require pacing. 2

• After valve surgery, 23.9% of patients with wires placed actually require temporary pacing, demonstrating substantial utilization. 3

• The timing of pacing need is unpredictable—while 50% of complications with temporary transvenous pacing occur within 24 hours, the other 50% occur later during hospitalization. 1

Risk Factors That Increase Pacing Requirements

Multiple patient and procedural factors increase the likelihood of needing postoperative pacing, but none reliably exclude the possibility:

Patient-related factors: 4, 2, 3

• Older age (particularly >60-65 years)
• Female sex
• Preoperative arrhythmias
• Preoperative renal failure
• Lower ejection fraction
• Diabetes mellitus
• Preoperative use of calcium channel blockers or digoxin
• New York Heart Association Class III-IV heart failure
• Pulmonary artery pressure ≥50 mmHg

Procedure-related factors: 4, 3

• Longer aortic cross-clamp times (≥60 minutes)
• Multiple valve surgery
• Valve annulus calcification
• Pacing required to separate from cardiopulmonary bypass
• Prior cardiac surgery

Risk-Benefit Analysis

The benefits of having wires in place outweigh the small but real risks:

Benefits:

• Immediate availability for rate support in symptomatic bradycardia or hemodynamic instability 1
• Maintenance of atrioventricular synchrony to optimize cardiac output 1
• Facilitation of postoperative recovery, including earlier ICU discharge, ambulation, and anticoagulation initiation 1
• Avoidance of emergent transvenous pacing with its higher complication rates (14-40% device-related complications) 5

Risks:

• Overall complication rate from wire removal is only 1.74% 6
• Specific complications include: wire retention (0.56%), arrhythmia (0.67%), delayed discharge (0.41%), and cardiac tamponade (0.1%) 6
• Rare but catastrophic bleeding leading to tamponade, surgical re-exploration, or death can occur with wire removal 1

Surgery-Specific Considerations

Coronary artery bypass grafting: Class IIa recommendation for routine wire placement, with recognition that off-pump procedures may warrant special consideration for omitting wires. 1

Aortic valve surgery: Class I recommendation for routine wire placement due to proximity of the conduction system to the surgical field and higher risk of heart block. 1

Mitral valve surgery: Class I recommendation for routine wire placement, with similar rationale regarding conduction system proximity. 1

Surgery for atrial fibrillation: Class I recommendation (strongest) because up to 65% of patients undergoing mitral surgery with AF receive concomitant AF surgery, and 11% develop postoperative conduction abnormalities requiring permanent pacing. 1

Common Pitfalls and Management Principles

• Wires should be removed as soon as clinically feasible (typically within 2-19 days) to minimize infection risk, as the presence of temporary wires before permanent pacemaker implantation increases the risk of device infections. 5, 7

• All patients with temporary epicardial pacing wires require continuous cardiac monitoring until the wires are removed or replaced with a permanent device. 1

• Timing of removal matters: Earlier removal (within 48-72 hours) associates with higher bleeding risk, while later removal (after 72 hours) associates with higher rates of delayed discharge. 6

• If new postoperative sinus node dysfunction or atrioventricular block with persistent symptoms or hemodynamic instability does not resolve, permanent pacing should be performed before discharge, typically 5-7 days after surgery. 1

• Selective omission of wires may be considered only in very low-risk patients undergoing isolated coronary artery bypass (no diabetes, no preoperative arrhythmia, no pacing needed during bypass separation), but no large study has clearly demonstrated benefit to this approach. 1