What is the initial treatment approach for a 65-year-old female patient with Paroxysmal supraventricular tachycardia (PSVT)?

Treatment for Paroxysmal Supraventricular Tachycardia in a 65-Year-Old Female

For a 65-year-old female with PSVT, initiate treatment with intravenous adenosine rather than vagal maneuvers alone, followed by consideration of oral AV nodal blocking agents for long-term management, with catheter ablation discussed as the definitive first-line option for preventing recurrence. 1, 2

Acute Treatment Algorithm

Immediate Hemodynamic Assessment

• If hemodynamically unstable (hypotension, altered mental status, chest pain with ischemia, acute heart failure), proceed directly to synchronized cardioversion at 50-100 J biphasic energy without attempting vagal maneuvers or medications. 3
• Ensure defibrillator availability before any treatment intervention in elderly patients due to risk of rhythm deterioration. 1

For Hemodynamically Stable Patients

Critical first step: Obtain a 12-lead ECG immediately to confirm narrow-complex tachycardia and exclude ventricular tachycardia and pre-excitation (delta waves), as treatment differs dramatically. 1, 4

Pharmacological Approach (Preferred in Elderly)

• Adenosine 6 mg rapid IV push through a large peripheral vein, followed by 20 mL saline flush, is the first-line acute treatment with 90-95% effectiveness. 3, 2
• Have resuscitation equipment immediately available when administering adenosine. 3
• Adenosine is contraindicated in asthma patients due to severe bronchoconstriction risk. 3
• Dose adjustments: reduce to 3 mg if patient takes dipyridamole, carbamazepine, or has transplanted heart; larger doses needed with theophylline or caffeine. 3

Vagal Maneuvers (Secondary Role in Elderly)

While guidelines recommend vagal maneuvers as Class I evidence for stable patients 3, elderly patients above 65 years have higher likelihood of coronary and cerebrovascular disease, making vagal maneuvers less safe and effective (only 18% conversion rate in ED studies versus 92% in young catheter-induced PSVT). 5 The modified Valsalva maneuver (bearing down for 10-30 seconds supine, then lying flat with legs elevated) is safer than carotid sinus massage in elderly patients. 3, 5

Long-Term Management Strategy

First-Line Definitive Treatment

Electrophysiology study with catheter ablation should be discussed as first-line therapy, providing 94.3-98.5% single-procedure success rates and definitive cure without chronic medication need. 1, 2

Pharmacological Prevention (If Ablation Declined)

Oral AV nodal blocking agents are first-line pharmacological therapy (Class I recommendation): 1

• Beta-blockers reduce episode frequency and duration 1
• Diltiazem or verapamil (calcium channel blockers) have proven efficacy 1
• Verapamil converted 86% of patients refractory to vagal maneuvers in ED studies 5

Alternative agents based on cardiac structure: 1

• Flecainide or propafenone (Class IIa) for patients without structural or ischemic heart disease, starting at 50 mg every 12 hours, increased by 50 mg increments every 4 days, maximum 300 mg/day for PSVT 1, 6
• Sotalol (Class IIb) for patients with structural heart disease 1

Critical Safety Warnings

Never use AV nodal blocking agents (verapamil, diltiazem, beta-blockers, adenosine) if pre-excitation is present on ECG, as they can accelerate ventricular rate through the accessory pathway and precipitate ventricular fibrillation. 3, 1 In such cases, use procainamide if hemodynamically stable or immediate cardioversion if unstable. 7

Avoid verapamil and diltiazem in patients with systolic heart failure or wide-complex tachycardia of uncertain etiology due to hemodynamic collapse risk. 3

Patient Education Component

Educate on modified Valsalva maneuver technique and ice-cold wet towel to face (diving reflex) for self-termination of future episodes, though effectiveness is limited in this age group. 1