Noninvasive cardiac hemodynamics monitoring of acute myocardial ischemia in rats using near-infrared spectroscopy: A pilot study

Noninvasive and real-time optical detection of cardiac hemodynamics dysfunction during myocardial ischemia remains challenging. In this study, we developed a near-infrared spectroscopy device to monitor rats' myocardial hemodynamics. The well-designed system can accurately reflect the hemodynamics changes by the classic upper limb ischemia test. Systemic hypoxia by disconnecting to the ventilator and cardiac ischemia by coronary artery slipknot ligation was conducted to monitor myocardial hemodynamics. When systemic hypoxia occurred, Delta HbR and Delta tHb increased significantly, whereas Delta HbO decreased rapidly. When coronary blood flow was obstructed by slipknots, cardiothoracic Delta HbO immediately begins to decline, while Delta HbR also significantly increases. Simultaneously, SpO2 did not show any obvious changes during myocardial ischemia, while SpO2 decreased significantly during systemic hypoxia. These results demonstrated that cardiothoracic hemodynamics stemmed from myocardial ischemia. This pilot study demonstrated the practicality of noninvasive, low-cost optical monitoring for cardiac oxygenation dysfunction in rats. A near-infrared spectroscopic device was developed for the real-time monitoring of hemodynamic changes during coronary artery occlusion in the rat heart. This was evidenced by a rapid decrease in Delta HbO and a marked increase in Delta HbR when rats' myocardial ischemia occurred, accompanied by a significant elevation of the electrocardiographic ST segments. It has also yielded new insights for monitoring ischemic heart disease. image