Autonomic neurocardiogenic syndrome is stonewalled by the universal definition of myocardial infarction

Figure 4 Mechanism of troponin elevation in autonomic neurocardiogenic syndrome. Illustration of the hypothetical mechanism of troponin release in autonomic neurocardiogenic syndrome including takotsubo syndrome and takotsubo-related conditions. The systo-diastolic compression of a coronary artery segment specially left anterior descending artery with myocardial bridging, the coronary slow flow due to increased microvascular resistance, the stiff and rigid myocardial stunning, and the hyper-contracted sarcomeres indicate that the affected myocardium in autonomic neurocardiogenic syndrome including takotsubo syndrome is in a state of cardiac cramp. This cardiac cramp may squeeze the cardiac myocyte causing release of troponins from the cytosolic free pool resulting in mild-moderate troponin elevation as demonstrated in the figure. C: Troponin C; I: Troponin I; T: Troponin T; ANCA: Autonomic neurocardiogenic.