Despite improvements in
cardiopulmonary resuscitation (
CPR) quality, defibrillation technologies, and implementation of
therapeutic hypothermia, less than 10 % of
out-of-hospital cardiac arrest (OHCA) victims survive to hospital discharge. New
resuscitation therapies have been slow to develop, in part, because the pathophysiologic mechanisms critical for
resuscitation are not understood. During
cardiac arrest, systemic cessation of blood flow results in whole body
ischemia.
CPR and the restoration of spontaneous circulation (ROSC), both result in immediate
reperfusion injury of the heart that is characterized by severe contractile dysfunction. Unlike diseases of localized
ischemia/reperfusion (IR) injury (
myocardial infarction and
stroke), global IR injury of organs results in profound organ dysfunction with far shorter ischemic times. The two most commonly injured organs following
cardiac arrest resuscitation, the heart and brain, are critically dependent on mitochondrial function. New insights into mitochondrial dynamics and the role of the mitochondrial fission
protein Dynamin-related
protein 1 (Drp1) in apoptosis have made targeting these mechanisms attractive for IR
therapy. In animal models, inhibiting Drp1 following IR injury or
cardiac arrest confers protection to both the heart and brain. In this review, the relationship of the major mitochondrial fission
protein Drp1 to ischemic changes in the heart and its targeting as a new therapeutic target following
cardiac arrest are discussed.