Wenckebach type block on surface ECG due to infra-Hisian location in a patient with repaired tetralogy of Fallot
Key result
In a 40-year-old man with repaired tetralogy of Fallot and infra-Hisian Wenckebach block, permanent dual-chamber pacemaker implantation resulted in freedom from symptoms over 18 months of follow-up.
Population
A 40-year-old man with a history of repaired tetralogy of Fallot presenting with a first episode of syncope.
Design
Case_report
Follow-up
18 months
Authors
Discussion
Loading...
Member takes
Implication
Pacing may relieve symptoms in repaired tetralogy of Fallot with infra-Hisian Wenckebach; leaves open prospective evaluation of indications in this population.
Key Points
- Investigate the electrophysiological mechanism underlying late-onset syncope and complex atrioventricular conduction disturbances in an adult after surgical repair of tetralogy of Fallot.
- Evaluated a 40-year-old man presenting with syncope 35 years after corrective tetralogy of Fallot surgery via surface electrocardiogram (ECG) and physical exertion testing.
- Conducted an invasive intracardiac electrophysiological study to record baseline and provocative AH and HV interval conduction dynamics.
- Implanted a permanent dual-chamber pacemaker and evaluated clinical outcomes across an 18-month follow-up period.
- Surface ECG displayed right bundle branch block (QRS duration 160 ms), left anterior hemiblock, and Mobitz I Wenckebach periodicity (3:2 and 4:3 ratios) that progressed to 3:1 high-degree block with moderate exertion.
- Electrophysiological study demonstrated a constant, normal AH interval alongside progressive HV prolongation (54 ms, 72 ms, and 87 ms) culminating in block after the His deflection, confirming an infra-Hisian site of failure.
- Dual-chamber pacemaker implantation eliminated conduction failure and resolved syncope, maintaining symptom-free status throughout the 18-month follow-up.
Study Design
Type
Case Report (n=1)
Structured PICO
P
Population
A 40-year-old man with repaired tetralogy of Fallot who presented with syncope and was followed for 18 months after pacemaker implantation.
I
Intervention
Permanent dual-chamber pacemaker implantation
O
Outcome
Symptom resolution (freedom from syncope)
Wenckebach type block can occur at the infra-Hisian level in patients with repaired tetralogy of Fallot, highlighting the need for careful electrophysiological evaluation and potential pacemaker implantation in this aging population.
Cite This Study
Marijon et al. (2008) conducted a case report in Repaired tetralogy of Fallot with syncope and AV block (n=1). Permanent dual-chamber pacemaker implantation was evaluated on Symptom recurrence. In a 40-year-old man with repaired tetralogy of Fallot and infra-Hisian Wenckebach block, permanent dual-chamber pacemaker implantation resulted in freedom from symptoms over 18 months of follow-up.