水野 朝敏¹, 鈴木 茂¹, 佐々木 達海¹, 宮沢 総介¹, 望月 吉彦¹, 小谷野 明², 新井 達太¹

Asatoshi MIZUNO¹, Shigeru SUZUKI¹, Tatsuumi SASAKI¹, Sousuke MIYAZAWA¹, Yoshihiko MOCHIZUKI¹, Akira KOYANO², Tatsuta ARAI¹

¹東京慈恵会医科大学心臓外科, ²アロカ株式会社

¹Department of Cardiovascular Surgery, Jikei University School of Medicine, ²Aloka Co. Ltd.

キーワード : Ultrasound stimulation, Cardiac function, Working heart mode, Verapamil cardioplegic solution

The mutual effect of ultrasound stimulation (Ul) and Verapamil (0.5 mg/l; Ve) on ventricular function were investigated in isolated per fused rat heart (male, Sprague Dawley-descent, body weight about 250 g). The hearts were per fused by working heart mode for 10 min as a baseline hemodynamic variables and they underwent infusion of cardioplegic solution (Young solution) via retrograde perfusion followed by 25 min of cardiac arrest with simultaneous occlusion of aortic outflow and left atrial tracts. The myocardial temperature was kept at 37 °C during cardiac arrest and the aerobic reperfusion was continued for an additional 30 min with the buffer temperature at 37 °C. The ultrasound was irradiated with the frequency of 1010 kHz, the intensity at 0.25 w/cm² and continuous wave during cardiac arrest in UlVe group and in Ul group. Results were follows, there was no significant difference in the recovery rate of coronary flow among four groups. However, the recovery of aortic output after 30 min of reperfusion was 26.5%, 82.9%, 83.4% and 65.9% of the preischemic value in control group, UlVe group, Ve group and Ul group, respectively which was statistically significant. These data suggest that the ultrasound stimulation might have a protective effect tagainst the ischemic insult in myocardial cell, but not exert Ca-overload during hypothermic cardioplegic arrest.