Real-time and continuous monitoring of myocardial blood flow using a thermal diffusion method.

Abstract

There has been no method which can measure regional myocardial blood flow in real-time and continuously. The purpose of this study was to validate myocardial blood flow measurement using a thermal diffusion method. For this purpose, myocardial blood flow measurement was performed using the thermal diffusion method and the electrolytic hydrogen clearance method. Seven pigs were used for this study, six were for comparison between the thermal diffusion and electrolytic hydrogen clearance methods, and one was for demonstration of myocardial blood flow measurement using the thermal diffusion method on a beating heart coronary artery bypass model with ischemic preconditioning. A good correlation was found between myocardial blood flow values obtained by the electrolytic hydrogen clearance method and 1/V values obtained by a thermal diffusion probe, the correlation coefficient was 0.841 (P<0.001). During the beating heart coronary artery bypass, the regional myocardial blood flow was recorded in real-time and continuously. This study demonstrated measurement of regional myocardial blood flow using the thermal diffusion method for the first time and simultaneous measurement using the electrolytic hydrogen clearance method for calibration. It provided a real-time and continuous myocardial blood flow measurement and has a potential to contribute to progress in beating-heart surgery.