What are the intra‑operative complications of premature ventricular contractions in a patient undergoing emergency surgery and how should they be monitored and managed?

Intraoperative Complications of PVCs in Emergency Surgery

Premature ventricular contractions encountered during emergency surgery do not require treatment unless they cause hemodynamic instability or symptoms, and their presence alone does not increase the risk of perioperative myocardial infarction or cardiac death. 1, 2

Risk Stratification During Emergency Surgery

The presence of PVCs—including complex ectopy and nonsustained ventricular tachycardia—should not delay emergency surgery, as these arrhythmias are not independently associated with increased perioperative mortality or morbidity in the absence of hemodynamic compromise. 1, 2 The key distinction is whether the PVCs are:

• Asymptomatic and hemodynamically stable: No intervention required 1, 2
• Causing hemodynamic compromise: Requires immediate treatment 2
• Associated with acute myocardial ischemia: Indicates underlying pathology requiring concurrent management 1, 2

Intraoperative Monitoring Requirements

Standard 12-lead ECG monitoring is adequate for patients with PVCs during emergency surgery. 2 No additional invasive hemodynamic monitoring is required solely because of the presence of PVCs. 2 Continuous electrocardiographic monitoring should focus on detecting:

• Sustained ventricular tachycardia
• Hemodynamic deterioration
• New ischemic changes
• Electrolyte-related QT prolongation 1, 2

Management Algorithm for Intraoperative PVCs

First-Line Approach: Observation

Unifocal or multifocal PVCs encountered intraoperatively require no pharmacologic treatment unless they produce hemodynamic instability or patient-reported symptoms. 2 This conservative approach is supported by evidence showing that asymptomatic ventricular arrhythmias, including couplets and nonsustained ventricular tachycardia, are not associated with increased cardiac complications after noncardiac surgery. 1

When to Treat: Hemodynamic Compromise

Very frequent ventricular ectopy or prolonged runs of nonsustained ventricular tachycardia merit antiarrhythmic therapy only if they are symptomatic or cause hemodynamic instability. 2 Treatment hierarchy:

1. Intravenous beta-blockers are the preferred first-line agents for controlling symptomatic ventricular arrhythmias during surgery 2, 3
2. Intravenous lidocaine, procainamide, or amiodarone may be used as alternative agents for refractory cases 2
3. Electrical cardioversion is indicated for sustained ventricular arrhythmias that produce hemodynamic compromise 2

Optimize Underlying Conditions

Maintaining adequate depth of anesthesia and optimizing hemodynamics helps minimize sympathetic stimulation that can exacerbate PVCs. 2 Address reversible precipitants:

• Electrolyte abnormalities: Correct hypokalemia and hypomagnesemia, which are common triggers 2, 4
• Myocardial ischemia: Ensure adequate coronary perfusion and oxygen delivery 1, 2
• Drug toxicity: Review anesthetic agents and other medications 1
• Metabolic derangements: Correct acidosis, hypoxia, and hypercarbia 1

Critical Pitfalls to Avoid

Routine suppression of PVCs with antiarrhythmic drugs in the absence of symptoms or hemodynamic compromise is not supported by evidence and may introduce medication-related risks. 2 Specifically:

• Never use Class IC agents (flecainide, propafenone) in patients with structural heart disease or prior myocardial infarction, as they increase mortality despite PVC suppression 4
• Avoid prophylactic antiarrhythmic therapy for asymptomatic PVCs, as this does not reduce perioperative cardiac events 1, 2
• Do not delay emergency surgery based solely on the presence of PVCs, even when frequent or complex 2

Special Circumstances Requiring Caution

Sustained or Symptomatic Ventricular Tachycardia

If sustained or symptomatic ventricular tachycardia develops intraoperatively and causes hemodynamic compromise, it requires immediate pharmacologic suppression with intravenous lidocaine, procainamide, or amiodarone, or electrical cardioversion. 2 This represents a true complication requiring urgent intervention.

Concurrent Acute Coronary Syndrome

When PVCs occur in the context of acute myocardial ischemia or infarction during emergency surgery, the focus should be on stabilizing the ischemic event rather than suppressing the PVCs themselves. 2 The PVCs are a marker of underlying pathology, not the primary problem.

Severe Left Ventricular Dysfunction

Patients with severe left ventricular dysfunction (ejection fraction < 35%) who develop frequent PVCs or nonsustained ventricular tachycardia intraoperatively warrant closer monitoring and consideration of postoperative cardiology consultation for potential ICD therapy. 2 However, this does not change the immediate intraoperative management approach.

Postoperative Considerations

Continue standard cardiac monitoring in the immediate postoperative period; no special monitoring is needed solely for PVCs. 2 Patients who develop sustained or nonsustained ventricular tachycardia perioperatively should be referred to cardiology for assessment of ventricular function and coronary artery disease screening. 2 Electrolyte abnormalities, particularly low potassium or magnesium, should be corrected in the postoperative period to reduce the risk of recurrent ectopy. 2