Would a complete electrophysiological study allow us to make a correct diagnosis? Case report

Area of Science:

• Clinical Electrophysiology
• Cardiology
• Medical Case Studies

Background:

• Oblique accessory pathways are uncommon and can be misdiagnosed.
• Distinguishing oblique pathways from multiple pathways requires thorough electrophysiological study.
• Novel findings include proximity of atrial and ventricular electrograms within the coronary sinus.

Purpose of the Study:

• To report a rare case of an oblique accessory pathway.
• To discuss the differential diagnosis between oblique and multiple accessory pathways.
• To emphasize the importance of diagnostic protocols in invasive electrophysiology.

Main Methods:

• A 68-year-old female patient with arrhythmias underwent electrophysiological study and ablation.
• Utilized Seldigner technique for femoral vein access and BIOTRONIK technology for mapping.
• Performed accessory pathway mapping in right/left cavities and coronary sinus (CS).

Main Results:

• Observed short atrioventricular (AV) intervals from proximal to distal CS electrodes.
• Successfully ablated two accessory pathway recordings at distinct epicardial points within the CS.
• Identified an oblique accessory pathway with an epicardial trajectory.

Conclusions:

• Ablation at two distant sites supports the presence of an oblique accessory pathway.
• This case highlights the differential diagnosis of oblique versus multiple accessory pathways.
• The observed electrogram sequence in the CS is unprecedented in reviewed literature.