What is the treatment for a 57-year-old obese female in Supraventricular Tachycardia (SVT)?

Treatment of SVT in a 57-Year-Old Obese Female

The first-line treatment for a 57-year-old obese female with SVT should be vagal maneuvers, followed by intravenous adenosine if vagal maneuvers fail, and synchronized cardioversion for hemodynamically unstable patients or when pharmacological methods are ineffective. 1

Initial Assessment and Stabilization

• Assess hemodynamic stability immediately:
  • If unstable (hypotension, altered mental status, signs of shock, severe chest pain)
    • Proceed directly to synchronized cardioversion 1
  • If stable, proceed with stepwise management

Treatment Algorithm for Hemodynamically Stable SVT

First-Line: Vagal Maneuvers

• Modified Valsalva maneuver is the most effective vagal technique 2:
  • Have patient in supine position
  • Patient bears down against closed glottis for 10-30 seconds (equivalent to 30-40 mmHg pressure)
  • Immediately after strain, lay patient flat and elevate legs
• Alternative vagal maneuvers:
  • Carotid sinus massage (after confirming absence of carotid bruits)
  • Applying ice-cold wet towel to face 1

Second-Line: Pharmacological Treatment

• If vagal maneuvers fail:

  • Adenosine IV (Class I recommendation):
    • Initial dose: 6 mg rapid IV push
    • If ineffective: 12 mg IV push, may repeat once if needed
    • Warn patient about transient flushing, chest discomfort 1

• If adenosine fails or is contraindicated:

  • IV beta blockers (Class IIa recommendation):

    • Metoprolol: 5 mg IV over 2-5 minutes, may repeat twice (total 15 mg)
    • Particularly useful in obese patients 1
    • Avoid in severe conduction abnormalities or sinus node dysfunction

  • IV calcium channel blockers (Class IIa recommendation):

    • Diltiazem: 0.25 mg/kg IV over 2 minutes
    • Verapamil: 5-10 mg IV over 2-3 minutes
    • Avoid in heart failure or pre-excited SVT 1

Third-Line: Electrical Cardioversion

• Synchronized cardioversion (Class I recommendation) when:
  • Pharmacological therapy fails
  • Patient becomes hemodynamically unstable
  • Initial energy: 50-100 J (biphasic) 1

Long-Term Management Considerations

• All patients should be referred to a heart rhythm specialist for evaluation 3
• Options include:
  • Beta blockers (metoprolol, propranolol) as first-line pharmacological option 4
  • Calcium channel blockers (diltiazem, verapamil)
  • Catheter ablation (Class I recommendation) for recurrent, symptomatic SVT 4

Special Considerations for Obese Patients

• Obesity may affect drug pharmacokinetics and dosing
• Higher risk of comorbidities (hypertension, sleep apnea, coronary artery disease)
• Consider underlying causes of SVT that may be exacerbated by obesity
• Monitor for adequate response to medications

Common Pitfalls to Avoid

• Failing to record a 12-lead ECG before and during treatment
• Misdiagnosing the type of SVT, which may lead to inappropriate treatment
• Using verapamil or diltiazem in pre-excited AF (can accelerate ventricular rate)
• Applying pressure to eyeballs (dangerous and abandoned practice) 1
• Delaying cardioversion in unstable patients
• Inadequate vagal maneuver technique (proper positioning and duration are essential)

Remember that the modified Valsalva maneuver has shown superior efficacy compared to standard techniques, with significantly higher conversion rates to sinus rhythm 2.