Neurogenic stunned myocardium - do we consider this diagnosis in patients with acute central nervous system injury and acute heart failure?

Abstract

Neurogenic stunned myocardium (NSM) is defined as myocardial injury and dysfunction of a sudden onset, occurring after various types of acute brain injury as a result of an imbalance in the autonomic nervous system. The typical spectrum of clinically observed abnormalities includes acute left ventricular failure, not uncommonly progressing to cardiogenic shock with hypotension that requires inotropic agents, pulmonary oedema and various arrhythmias. Commonly-seen electrocardiographic changes include: prolonged QT interval, ST segment changes, T-wave inversion, a new Q-wave or U-wave. Echocardiography shows both an impaired both systolic and diastolic function of the left ventricle. Biochemical markers of NSM comprise metabolic acidosis and increased cardiac enzymes and markers: creatine kinase (CK), and CK-MB, troponin I and B-type natriuretic peptide. The main cause of NSM is myocardial injury induced by local catecholamine release from nerve endings within the myocardium. Recently, a theory has been proposed to classify NSM as one of the stress-related cardiomyopathies, together with Takotsubo cardiomyopathy, acute left ventricular failure in the critically ill, cardiomyopathy associated with pheochromacytoma and exogenous catecholamine administration. The occurrence of NSM increases the risk of life-threatening complications, death, and worsens neurologic outcome. As far as we know, treatment should generally focus on the underlying neurologic process in order to maximize neurologic recovery. Improvement in neurologic pathology leads to rapid improvement in cardiac function and its full recovery, as NSM is a fully reversible condition if the patient survives. Awareness of the existence of NSM and a deeper knowledge of its etiopathology may reduce diagnostic errors, optimise its treatment.