Cardiac stunning in the clinic: the full picture

Abstract

Cardiac stunning refers to different dysfunctional levels occurring after an episode of acute ischemia, despite blood flow is near normal or normal. The phenomenon was initially identified in animal models, where it has been very well characterized. After being established in the experimental setting, it remained unclear, whether a similar syndrome occurs in humans. In addition, it remained controversial, whether stunning was of any clinical relevance as it is spontaneously reversible. Hence, many studies continue to focus on the properties and mechanisms of stunning, although therapies seem more relevant for attenuating and treating myocardial ischemia/reperfusion (I/R) injury, i.e. to bridge until recovery. This article reviews the different facets of cardiac stunning, i.e. myocardial, vascular/microvascular/endothelial, metabolic, neural/neuronal, and electrical stunning. This review also displays where these facets exist and which clinical relevance they might have. Particular attention is directed to the different therapeutic interventions that the various facets of this I/R-induced cardiac injury might require. A final outlook considers possible alternatives to further reduce the detrimental consequences of brief episodes of ischemia and reperfusion.

Lipid Emulsion Rapidly Restores Contractility in Stunned Mouse Cardiomyocytes

“…Despite a lack of tissue death, stunned myocardium takes weeks to regain full contractile function, elevating morbidity and mortality (2) and requiring inotropic support to maintain cardiac output (3, 4). Many drugs have been tested to protect the myocardium from stunning and related injury, but with mixed clinical outcomes (5).…”

Cardiac stunning as a manifestation of ATRA differentiation syndrome in acute promyelocytic leukemia

“…Moreover, cardiac biomarkers returned to normal levels rapidly, instead of the slow fall commonly observed in this syndrome. For these reasons, we believe that clinical picture herein described could be defined as a myocardial stunning [13]. This entity is an acknowledged clinical condition that occurs whenever ischemia is followed by reperfusion.…”

Chemical chaperones improve the functional recovery of stunned myocardium by attenuating the endoplasmic reticulum stress

“…Furthermore, our data suggest that prevention of the ER stress by the use of chemical chaperones could be a therapeutic tool to limit the deterioration of the contractile function in clinical settings such as spontaneous reperfusion after revascularization therapies or after thrombolysis subsequent to acute myocardial infarction. 46…”