• Accessory Pathways
• Mahaim Syndrome
• ECG and Mahaim Syndrome

Accessory Pathways

• Physiologically, the atria and ventricles are electrically isolated
• The only electrical connection is the AV junction
• If the AV junction is interrupted, a third-degree AV block occurs (electrical isolation of the atria from the ventricles)
• 0.5% of the population has an additional accessory pathway besides the AV junction
• The atria and ventricles are electrically connected through two pathways:
• AV junction
• Accessory pathway
• 10% of patients with an accessory pathway also have a secondary accessory pathway
• which is often inactive
• Based on location, there are three primary accessory pathways:
• Kent bundle
• Connects the atria and ventricles
• (Atrio-Ventricular bypass)
• Creates WPW syndrome
  
  
• James bundle
• Connects the atria to the His bundle
• (Atrio-Hisian bypass)
• Creates LGL syndrome
  
  
• Mahaim bundle
• Connects the AV junction to the ventricles
• (Nodo-Ventricular bypass)
• Creates Mahaim syndrome

ECG and Mahaim Syndrome

• Normal PQ interval (0.12 - 0.20s)
• Delta wave