Abstract 19150: Real Time Mitochondrial Monitoring Using Surface Raman Resonance Spectroscopy Detects Impending Cardiac Arrest

Aims: Global markers of perfusion (e.g. serum lactic acid) are unable to detect critical defects in myocardial (or other local) tissue oxygen delivery. As oxygen becomes limiting, electrons accumulate and proteins in the mitochondrial electron transport system become more reduced. We sought to continuously monitor mitochondrial redox status in order to rapidly detect impending organ dysfunction. Methods and Results: We developed a Raman resonance spectroscopy system (RRS, A) to quantify the ratio of reduced versus oxidized mitochondrial proteins (reduced mitochondrial fraction, RMF). We first generated oxidized (100% O2) and reduced (100% N2 and sodium dithionate) RRS spectra in isolated rat cardiac mitochondria; the RRS spectra of oxy- and deoxy- hemoglobin and myoglobin spectra were similarly defined (B). Using these spectra, we quantified RMF in an isolated Langendorff rat heart model (C, n=8) where coronary flow rate was decreased in graded fashion from 100% (baseline) to 0% (10 minutes at each flow r...