Purpose of review: To present a method enabling in vivo quantification of tissue membrane potential (ΔΨT), a proxy of mitochondrial membrane potential (ΔΨm), to review the origin and role of ΔΨm, and to highlight potential applications of myocardial ΔΨT imaging.
Recent findings: Radiolabelled lipophilic cations have been used for decades to measure ΔΨm in vitro. Using similar compounds labeled with positron emitters and appropriate compartment modeling, this technique now allows in vivo quantification of ΔΨT with positron emission tomography. Studies have confirmed the feasibility of measuring myocardial ΔΨT in both animals and humans. In addition, ΔΨT showed very low variability among healthy subjects, suggesting that this method could allow detection of relatively small pathological changes. In vivo assessment of myocardial ΔΨT provides a new tool to study the pathophysiology of cardiovascular diseases and has the potential to serve as a new biomarker to assess disease stage, prognosis, and response to therapy.
Keywords: Heart failure; Mitochondria; Mitochondrial membrane potential; Positron emission tomography; Tissue membrane potential; Triphenylphosphonium.