How to manage tachycardia in a preoperative orthopedic (ortho) patient?

Management of Tachycardia in Preoperative Orthopedic Patients

Beta-blockers are the first-line treatment for managing tachycardia in preoperative orthopedic patients, with metoprolol being the preferred agent due to its relative beta-1 selectivity and proven efficacy in reducing perioperative arrhythmias. 1

Initial Assessment and Workup

1. Determine the type of tachycardia:

   • Obtain 12-lead ECG to differentiate between:
     • Sinus tachycardia
     • Supraventricular tachycardia (SVT)
     • Atrial fibrillation/flutter
     • Ventricular tachycardia

2. Identify underlying causes:

   • Search for:
     • Cardiopulmonary disease
     • Ongoing myocardial ischemia
     • Drug toxicity
     • Metabolic derangements (electrolyte abnormalities)
     • Hyperthyroidism
     • Pain/anxiety

Management Algorithm Based on Tachycardia Type

Sinus Tachycardia

• Treat the underlying cause (pain, anxiety, hypovolemia, anemia)
• Beta-blockers (metoprolol) for rate control if no contraindications 1, 2
• Target heart rate: <100 bpm or <20% above baseline

Supraventricular Tachycardia (SVT)

• For acute termination:
  • Vagal maneuvers
  • Adenosine IV if vagal maneuvers fail
  • Verapamil or diltiazem if adenosine fails 1
• For prevention:
  • Beta-blockers (metoprolol) as first-line therapy 1

Atrial Fibrillation/Flutter

• Rate control with:
  • Beta-blockers (most effective agent) 1
  • Calcium channel blockers (diltiazem, verapamil) if beta-blockers contraindicated
  • Consider anticoagulation based on thromboembolic risk assessment 1

Ventricular Tachycardia

• Asymptomatic nonsustained VT usually doesn't require therapy unless associated with:
  • Hemodynamic compromise
  • Ongoing/threatened myocardial ischemia
  • LV dysfunction 1
• For sustained or symptomatic VT:
  • IV lidocaine, procainamide, or amiodarone 1
  • Electrical cardioversion if hemodynamically unstable 1

Specific Pharmacological Management

Beta-Blockers (First-Line)

• Metoprolol: Start with 25-50 mg PO BID, titrate as needed 3
  • Benefits: Reduces incidence of perioperative arrhythmias 1, 4
  • Caution: Monitor for bradycardia and hypotension 3, 5
  • Contraindications: Severe bradycardia, heart block, cardiogenic shock, decompensated heart failure 3

Calcium Channel Blockers (Alternative)

• Diltiazem/Verapamil: Consider when beta-blockers are contraindicated 1
• Avoid in pre-excited AF (WPW syndrome) 1

Other Agents

• Amiodarone: For ventricular arrhythmias or when other agents fail 1
• Digoxin: Less effective than beta-blockers, consider as second-line for AF 1, 2

Special Considerations

Patients with Implanted Devices (Pacemakers/ICDs)

• Determine if patient is pacemaker-dependent
• Consider reprogramming to asynchronous mode (VOO or DOO) during surgery
• For ICDs, deactivate tachyarrhythmia treatment algorithms preoperatively
• Ensure continuous cardiac monitoring when ICD tachytherapy is inactivated 1
• Have external defibrillation equipment readily available 1

Electrocautery Precautions

• Use bipolar electrocautery system if possible
• Apply short, intermittent bursts at lowest possible energy
• Maximize distance between electrocautery and device
• Position ground patch to minimize current flow through device 1

Common Pitfalls to Avoid

• Attributing tachycardia to anxiety without adequate cardiac evaluation 2
• Failing to search for underlying causes of arrhythmias (ischemia, electrolyte abnormalities) 1
• Abrupt discontinuation of beta-blockers which can precipitate rebound tachycardia 3
• Overlooking medication side effects such as bronchospasm with beta-blockers 3
• Dismissing ventricular arrhythmias in patients with structural heart disease 1

Beta-blockers remain the cornerstone of management for most forms of tachycardia in the preoperative setting, with careful consideration of the underlying cause and patient-specific factors to guide therapy selection and dosing.