| Aim of studyMyocard could be abalated directly by means of interventional technique now. It is a milestone to the therapy of heart diseases .These means of cardial intervention ablation including radiofrequency and anhydrous alcohol filling have some shortages in clinic,for examples,the action depth is too superficial for radiofrequency ablation myocardium and safety too bad for anhydrous alcohol. So ,We are looking for some safe,controllable,powerful myocardium ablation method to substitute radiofrequency and anhydrous alcohol .Because ultrasound have strong penetrativity to body and good controllability and powerful action. It has a chance to take the place of the two meanses of myocardium ablation in abstrcto . From many studies of ultrasonic myocardium ablation. We found ultrasound could induce clear myocardium ablation lesion that depth farmer than radiofrequency . It also can control ablation lesion's limit through adjusting ultrasonic parameter.Sonodynamic therapy(SDT) have advantages of ultrasound'penetrativity and Photodynamic therapy (PDT). The actions include that ultrasound damage cell directly and ultrasound activate photosensitizer, then create free radical and active oxygen tha can attack cell . The SDT ablation is powerful and controllable like ultrasound. Because ultrasonic cavitation is only a trigger . The action of ultrasound activating photosensitizer play more important role. the safety of SDT is better than ultrasound.The sonosensitizer for instance hemotoporfrin have a feature accumulating in tumor. So SDT often being use to stuy of tumor and scarcely to normal tissue .In this study ,SDT first time being using to myocardial ablation in vivo and compare two SDT'ablation effects through different hemotoporfrin admistrations and ultrasonic myocardium ablation each other. Then sure reliability of SDT to myocardial ablation.MethodsEquipments and materials: hai ji xing ultrasound, the power is adopted 1 watt,and frequency 9.70 million hertz; and the irradiance time is 1 mimutes. sonosensitizer is hemotoporfrin injection and concentration is 25mg/ml.Means of ainimal operation: aimimals were rabbits had been abrosiaed 24 hours before operation. Pentobarbital was used to anesthesia by muscle injection and sodium sulfide depilate. Rabbites were fixed on animal desk and opened chest through center path. Pericardium was suspled to expose heart.drug was been injected directly into left cardic ventricle and ultrasound irradianced left ventricle. Closed chest after operation.rabbits have been away from light 48 hours.Ainimal groups 30 rabbits divided into 5groups: US group ultrasound irradiance left ventricle ; SDTI group ultrasound irradiance + Hp injected myocarddirectly; SDTII group ultrasound irradiance + Hp injected into vein; HpI group Hp injected intomyocard ; HpII group Hp injected into vein.Rabbits were killed afer 48 hours and heart were take out.The cardices were cut into ring form slices following the way of ultrasound irradiance.observing the the shapes of the myocardic lesions.Quantitative analyses: Tetrazolium chloride(TTC) dyed the cardic and contrasted the shapes of lesions before and after TTC dyeing. The depth ,length and volum were measured and compared by stastistic Qualitative analyses: The cardic lesions were fixed by 10% formaldehyde to make hematoxylin-eosin staining(HE ) and by 2.5 % glutaral to make transmission electron microscope(TEM)Results(1)SDT induced clear myocardium ablation lesions, the lesion afer TTC dyeing weren't changed . (2)Two SDT groups'ablation lesions were not stastistic different .(3)Ultrasound induced mycardic injured but the degree and extent were less than SDT(4)High concentration Hp injected into cardic directly could induce a small quantity cadiocyte to degen.Conclusion(1)There have SDT effects in myocard(2)SDTs being administered drug through two path haven't obvisouly difeerence(3)High concentration Hp could damage cadiocyte.(4)SDT ablation to cardic have some feasibility...
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