@inproceedings{697294aea0b24d48bcf97991b20b1c71,
title = "The new application of photosensitization reaction to atrial fibrillation treatment: Mechanism and demonstration of non-thermal electrical conduction block with porcine heart",
abstract = "We have proposed non-thermal electrical conduction block for atrial fibrillation treatment by the photosensitization reaction, in which the interval time between the photosensitizer injection and irradiation is less than tenth of that in conventional way. To study the mechanism of photosensitization reaction-induced electrical conduction block, intracellular Ca2+ concentration change in rat myocardial cells was measured by fluorescent Ca 2+ indicator Fluo-4 AM with confocal laser microscopy. Measured rapid increase in the fluorescence intensity and a change in cell morphology indicated that cell membrane damage; that is Ca2+ influx and eventually cell death caused by the photosensitization reaction. To demonstrate myocardial electrical conduction block induced by the photosensitization reaction, surgically exposed porcine heart under deep anesthesia was used. The myocardial tissue was paced with a stimulation electrode. The propagated electrical signals were measured by bipolar electrodes at two different positions. Thirty minutes after the injection of 5-10 mg/kg Porfimer sodium or Talaporfin sodium, the red laser light was irradiated to the tissue point by point crossing the measuring positions by the total energy density of less than 200 J/cm2. The electrical signal conduction between the measuring electrodes in the myocardial tissue was delayed by each irradiation procedure. The electrical conduction delay corresponded to the block line length was obtained. These results demonstrated the possibility of non-thermal electrical conduction block for atrial fibrillation treatment by the photosensitization reaction.",
keywords = "Porfimer sodium, Talaporfin sodium, electrical conduction block, intracellular free Ca concentration, photosensitization reaction, therapy (PDT)",
author = "Arisa Ito and Hiroki Matsuo and Tsukasa Suenari and Takuro Kajihara and Takehiro Kimura and Shunichiro Miyoshi and Satoshi Ogawa and Tsunenori Arai",
year = "2009",
month = dec,
day = "1",
doi = "10.1117/12.822924",
language = "English",
isbn = "9780819476609",
series = "Progress in Biomedical Optics and Imaging - Proceedings of SPIE",
booktitle = "12th World Congress of the International Photodynamic Association - Photodynamic Therapy",
note = "12th World Congress of the International Photodynamic Association - Photodynamic Therapy: Back to the Future ; Conference date: 11-06-2009 Through 15-06-2009",
}