Will an AV (Atrioventricular) sequential pacemaker treat Supraventricular Tachycardia (SVT)?

AV Sequential Pacemakers Are Not First-Line Treatment for SVT

AV sequential pacemakers are not recommended as primary therapy for supraventricular tachycardia (SVT) and should only be considered in specific cases when catheter ablation and medications have failed.

First-Line Management of SVT

The management of SVT follows a clear hierarchy of interventions based on the 2015 ACC/AHA/HRS guidelines 1:

1. Acute termination:

   • Vagal maneuvers: First-line intervention for acute termination (Valsalva maneuver, carotid sinus massage)
   • Adenosine: Highly effective (95% success rate) for AVNRT and orthodromic AVRT
   • IV calcium channel blockers or beta blockers: For hemodynamically stable patients
   • Synchronized cardioversion: For hemodynamically unstable patients or when medications fail

2. Long-term management:

   • Catheter ablation: First-line therapy for recurrent, symptomatic SVT 2
   • Pharmacologic therapy: Beta blockers, calcium channel blockers, or other antiarrhythmics when ablation is not desired or feasible

Role of Pacemakers in SVT Management

Pacemakers have a limited role in SVT management:

• Class IIa recommendation: Permanent pacing is reasonable for symptomatic recurrent SVT that is reproducibly terminated by pacing when catheter ablation and/or drugs fail to control the arrhythmia or produce intolerable side effects 1, 3

• Mechanism: Pacemakers can interrupt reentrant SVTs using programmed stimulation and short bursts of rapid pacing by disrupting the reentry circuit 3

• Efficacy: Approximately 30-60% of atrial tachyarrhythmias can be terminated with atrial anti-tachycardia pacing (ATP) in patients with pacemakers 3

Important Considerations and Limitations

1. Safety concerns:

   • All pacing for SVT termination should be done in the atrium because of the risk of ventricular pacing-induced proarrhythmia 1, 3
   • Extensive testing is required before implantation to ensure the device safely terminates arrhythmias without accelerating the tachycardia 1

2. Contraindications:

   • Not indicated for SVT in patients with accessory pathways having capacity for rapid anterograde conduction
   • Should not be used for tachycardias that are accelerated or converted to fibrillation by pacing 3

3. Limited evidence:

   • While older studies showed some benefit in drug-resistant SVT 4, modern guidelines place pacemaker therapy after catheter ablation and drug therapy in the management algorithm

Conclusion

AV sequential pacemakers should be reserved for specific cases of recurrent, symptomatic SVT that are reproducibly terminated by pacing when first-line therapies (catheter ablation and medications) have failed. The decision to use a pacemaker for SVT control should be made only after careful evaluation by electrophysiology specialists 3.