Pathophysiology and pathogenesis of post-resuscitation myocardial stunning

The prognosis for cardiac arrest victims remains dismal, as only 17% survives to hospital discharge. Post-resuscitation myocardial stunning is the mechanical dysfunction that persists after the restoration of spontaneous circulation. Our knowledge regarding myocardial stunning has grown dramatically over the years, and several hypotheses have been proposed in order to explain its pathophysiology; however, the interrelationships among various mechanisms remain unclear. This review deals primarily with the basic aspects of the pathophysiology of post-resuscitation myocardial stunning. Given the large number of relevant studies and the fragmented information, an effort was made to summarize current knowledge in order to present a comprehensive pathophysiological mechanism. In this review, the pathophysiological disturbances occurring from the onset of cardiac arrest until the restoration of spontaneous circulation are addressed. Then, the pathophysiology of myocardial stunning during the post-resuscitation period is critically reviewed in 4 parts, the immediate, the early, the intermediate, and the recovery post-arrest phase. This article covers a huge gap in the existing literature regarding the pathophysiology of post-resuscitation period and provides a better understanding of the pathophysiology and pathogenesis of post-resuscitation myocardial stunning.