Management of SVT in a 67-Year-Old with Palpitations
An electrophysiology study with the option of catheter ablation is the recommended next step for this 67-year-old patient with documented SVT episodes on Zio monitor. 1
Assessment of Current Findings
The 14-day Zio monitor has provided valuable diagnostic information:
- 33 episodes of SVT
- Maximum heart rate of 235 bpm
- Episodes lasting up to eight beats
These findings confirm the diagnosis of SVT and provide evidence of potentially significant arrhythmia burden that warrants definitive treatment.
Management Algorithm
Step 1: Referral to Cardiac Electrophysiologist
- The patient should be referred to a cardiac electrophysiologist for evaluation and treatment
- This is indicated for patients with documented SVT who are symptomatic (palpitations) 1
- The high heart rate (235 bpm) indicates potential risk for hemodynamic compromise, particularly in a 67-year-old
Step 2: Electrophysiology Study with Ablation Option
- EP study is recommended as Class I (Level B-NR) for diagnosis and potential treatment of SVT 1
- Benefits:
- Provides definitive diagnosis of the specific SVT mechanism
- Offers potential for curative treatment without need for chronic pharmacological therapy
- High success rates for ablation of common SVT mechanisms (AVNRT, AVRT)
- Low frequency of serious complications 1
Step 3: If Ablation is Delayed or Patient Declines
If there is a delay before EP study/ablation or if the patient declines this procedure, pharmacologic therapy should be initiated:
First-line pharmacotherapy:
- Oral beta blockers, diltiazem, or verapamil (Class I, Level B-R) 1
- These AV nodal blockers are appropriate for long-term prophylactic therapy
Second-line options (if first-line ineffective or contraindicated):
- Flecainide or propafenone (Class IIa, Level B-R) 1, 2, 3
- Only if patient has no structural heart disease or ischemic heart disease
- Flecainide dosing: Start at 50 mg twice daily, may increase in 50 mg increments every 4 days to maximum 300 mg/day 2
- Propafenone has shown 53-67% attack-free rates in clinical trials 3
Third-line option:
- Sotalol (Class IIb, Level B-R) 1
- Can be used in patients with structural heart disease (unlike flecainide/propafenone)
- Requires careful monitoring due to proarrhythmic potential
Important Considerations
Age-Related Factors
- At 67 years old, this patient has higher risk of underlying structural heart disease
- Before initiating antiarrhythmic drugs, an echocardiogram should be performed to assess cardiac structure and function 1
Monitoring Requirements
- If pharmacologic therapy is chosen, follow-up with ECG monitoring is essential
- For class IC agents (flecainide, propafenone), monitoring for proarrhythmic effects is crucial
Patient Education
- Teach the patient proper vagal maneuvers for acute termination of SVT episodes 1
- Valsalva maneuver: forcefully exhaling against a closed airway for 10-30 seconds in supine position
- Cold stimulus to face (ice-cold wet towel) can also trigger vagal response
Common Pitfalls to Avoid
Delaying definitive treatment: SVT can lead to tachycardia-mediated cardiomyopathy if persistent 1, 4
Using class IC antiarrhythmics without ruling out structural heart disease: Flecainide and propafenone are contraindicated in patients with structural heart disease due to proarrhythmic risk 1, 2
Failing to refer for EP study: Catheter ablation has success rates of 94-98% 4 and should be considered first-line for definitive treatment rather than long-term pharmacotherapy
Inadequate follow-up: Even after successful ablation, patients should have follow-up to ensure resolution of symptoms and absence of recurrence
The evidence strongly supports EP study with ablation as the most effective approach for this patient with documented SVT and symptoms, offering the best outcomes for morbidity, mortality, and quality of life 1, 4.