The cause of takotsubo cardiomyopathy is not fully understood, but several mechanisms have been proposed. It is well documented that elevated catecholamine levels have been implicated in the vast majority of TTS cases. Theories suggest a link between brain activation of stress-related biochemicals and the effects these chemicals have on areas of the heart. More specifically, adrenal stimulation by the sympathetic nervous system has been noted in cases ranging from physical events such as ischemic stroke, to emotional events such as depression or loss of a loved-one. How these increased levels of catecholamines act in the body to produce the changes seen with TTS is not clearly understood. Research supports the widely-held understanding that microvascular dysfunction and coronary vasospasm caused by a rapid influx of catecholamines to cardiac myocytes results in apical stunning and transient cardiomyopathy.