Current Density Distribution by Ring and Diagonally Arranged Half-ring Electrodes in Bipolar and Ove

• 作 者: Satoru Suzuki
• 机 构: Department of Cardiovascular Surgery Hiratsuka City Hospital Japan
• 出 处: BITs 2rd Annual World Cancer Congress of Cardiology-2010(201
• 发表日期: 2010年12期

　　Background: We have studied the acute and long-term efficacy of overlapping biphasic impulse (OLBI) stimulation for atrial pacing with VDD pacemakers and demonstrated the feasibility of DDD pacing in OLBI stimulation using diagonally arranged half-ring (Half-Ring) electrodes as VDD single-leads.We made two three-dimensional computational analysis models to verify our clinical studies.Method: Model Ⅰ was composed of a heart model, a pacemaker model and a human body model.Model Ⅱ was a cube with dimensions of 20 by 20 by 20 mm quarried from Model Ⅰ for the detailed study of current density distributions.Laplaces equation was solved using the finite element method and the current density J was calculated.For Model Ⅰ, the distal and proximal voltages were-10 V, 0 V in bipolar and-5 V, +5 V in OLBI, using Ring electrodes.In Model Ⅱ the actual measurements of electrode impedances obtained from our clinical study (1180 Ω for Ring and 630 Ω for Half-Ring) were added to the analysis conditions.Result: Model Ⅰ showed that OLBI produced more concentrated current density distributions than those by bipolar.According to Model Ⅱ, at the atrial myocardium position current density produced by Half-Ring was larger than that by Ring electrodes,70 μA/mm2-vs.30 μA/mm2 in OLBI configuration.It also indicated that even if electrode impedances were equal between Half-Ring and Ring electrodes, the maximum current density produced by Half-Ring would be greater than that by Ring electrodes.Conclusion: it was considered that OLBI configuration with Half-Ring electrodes provides more effective current density distributions.This study also suggested that computational analysis models are useful for designing a new lead model.