Congenital complete heart block and vasodepressor syncope

Area of Science:

• Cardiology
• Electrophysiology
• Autonomic Dysfunction

Background:

• Congenital complete heart block necessitates pacemaker implantation for hemodynamic stability.
• Rate-responsive dual-chamber pacemakers are commonly used in pediatric and young adult populations.
• Syncope following pacemaker insertion warrants thorough investigation into potential underlying causes.

Observation:

• An 18-year-old male with congenital complete heart block experienced recurrent syncope post-pacemaker implantation.
• Head-up tilt table testing revealed a significant vasodepressor response with severe hypotension, reproducing the patient's symptoms.
• The patient's symptoms were directly linked to autonomic dysfunction rather than pacemaker malfunction.

Findings:

• The vasodepressor response, characterized by severe hypotension, was the primary cause of syncope.
• Pharmacological intervention with fludrocortisone and increased salt intake effectively abolished the syncopal episodes.
• Repeat head-up tilt testing after treatment showed a negative response, confirming symptom resolution.

Implications:

• This case highlights the importance of considering and evaluating for autonomic dysfunction, specifically vasodepressor syncope, in young pacemaker recipients presenting with recurrent syncope.
• Fludrocortisone and salt supplementation represent a viable and effective treatment strategy for managing vasodepressor syncope in patients with congenital heart block and pacemakers.
• Optimizing pacemaker settings and exploring medical management for autonomic dysfunction can improve quality of life in patients with complex congenital heart conditions.