BIOTRONIK dual coil ICD leads inter-coil spacing options?

• A. 16-18 cm
• B. 10-12 cm
• C. 20-22 cm
• D. 5-7 cm

Answer: (A)

Inter-coil spacing is the distance between the two defibrillation coils along a dual-coil ICD lead. That spacing sets the shock vector, which is the path the delivered energy takes through the chest and heart. In BIOTRONIK dual-coil leads, the design uses a moderate, mid-range spacing so the proximal coil sits high in the superior vena cava/right atrial region and the distal coil sits in the right ventricle. This arrangement creates a broad current path through the ventricles, improving the likelihood of effective defibrillation and producing more consistent thresholds across different body sizes. If the coils were too close together, the vector could be less effective for engaging the ventricles; if they were too far apart, energy delivery could become less efficient or the coils could interact unfavorably. That balanced, mid-range spacing is why this option is considered correct.