Cooling Device for Bradycardia Based on Peltier Element for Accurate Anastomosis of Off-Pump Coronary Artery Bypass Grafting

: Upon introducing off‐pump coronary artery bypass grafting (CABG), the indications for CABG were expanded to include patients who previously had no operative indications. For accurate anastomosis, various devices and methods have been developed. Bradycardia is easily induced by drug administration. However, this method of achieving bradycardia also has adverse effects on cardiac function. We have developed a new device to decrease the heart rate by regional cooling of the sino‐atrial node. The new device is incorporated with Peltier's element, which uses an electric charge to create a temperature gradient on both of its surfaces. In terms of the cooling ability of this device, its cooling surface is chilled from 25°C to 0°C within 30 s. During in vivo animal experiments, this device has been shown to decrease the myocardial temperature around the sino‐atrial node to 15°C and suppress sino‐atrial node activity, resulting in bradycardia to 60 beats/min level. In summary, the simple and easily applicable device for local cooling in combination with the application of diltiazem for effective heart rate reduction may be very helpful for the surgeon and may avoid disadvantages for critically ill patients.