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Misleading ECG appearance of AV block due to concealed AV nodal conduction caused by interpolated ventricular ectopic

Hasan Ari1, Selma Ari, Vedat Koca

  • 1Department of Cardiology, Bursa Postgraduate Hospital, Bursa, Turkey. hasanari03@yahoo.com

Turk Kardiyoloji Dernegi Arsivi : Turk Kardiyoloji Derneginin Yayin Organidir
|June 26, 2009
PubMed

Insights

Premature ventricular complexes can cause concealed conduction, leading to atrioventricular block. Metoprolol effectively treated a patient experiencing fatigue and palpitations due to this condition.

Area of Science:

  • Cardiology
  • Electrophysiology

Background:

  • Concealed conduction, often due to interpolated ectopic impulses, affects atrioventricular (AV) node function.
  • This can result in non-conduction or prolonged PR intervals of subsequent sinus beats due to AV conduction system refractoriness.

Observation:

  • A 67-year-old male presented with exertional fatigue and palpitations.
  • Electrocardiogram showed frequent premature ventricular complexes (PVCs) with right bundle branch block morphology.
  • Holter monitoring revealed interpolated PVCs, progressive PR prolongation, and Mobitz type I atrioventricular block.

Findings:

  • The patient's symptoms were directly linked to frequent interpolated PVCs causing concealed conduction and subsequent AV block.
  • Treatment with metoprolol led to a significant reduction in PVCs and resolution of AV block and symptoms.

Implications:

  • This case highlights the clinical significance of concealed conduction from PVCs in causing symptomatic AV block.
  • Pharmacological management with beta-blockers can be effective in managing such conditions.
  • Understanding this mechanism is crucial for diagnosing and treating arrhythmias involving AV nodal function.

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