Catecholamine-induced cardiotoxicity: A critical element in the pathophysiology of stroke-induced heart injury.

Cerebrovascular diseases such as ischemic stroke, brain hemorrhage, and subarachnoid hemorrhage provoke cardiac complications such as heart failure, neurogenic stress-related cardiomyopathy and Takotsubo cardiomyopathy. With regards to the pathophysiology of stroke-induced heart injury, several mechanisms have been postulated to contribute to this complex interaction between brain and heart, including damage from gut dysbiosis, immune and systematic inflammatory responses, microvesicle- and microRNA-mediated vascular injury and damage from a surge of catecholamines. All these cerebrovascular diseases may trigger pronounced catecholamine surges through diverse ways, including stimulation of hypothalamic-pituitary adrenal axis, dysregulation of autonomic system, and secretion of adrenocorticotropic hormone. Primary catecholamines involved in this pathophysiological response include norepinephrine (NE) and epinephrine. Both are important neurotransmitters that connect the nervous system with the heart, leading to cardiac damage via myocardial ischemia, calcium (Ca) overload, oxidative stress, and mitochondrial dysfunction. In this review, we will aim to summarize the molecular mechanisms behind catecholamine-induced cardiotoxicity including Ca overload, oxidative stress, apoptosis, cardiac hypertrophy, interstitial fibrosis, and inflammation. In addition, we will focus on how synchronization among these pathways evokes cardiotoxicity.