38) CMR can be useful in the assessment of SCMP. The distinction between an ischemic process vs. SCMP can be difficult at times. Patients who have the left anterior descending coronary artery thrombus which then recannulated can appear to have no significant disease on coronary angiogram, and may mistakenly be diagnosed with SCMP. Furthermore, patients with microvascular obstruction may have normal appearing epicardial vessels on coronary angiography. CMR can differentiate between ischemic etiologies and SCMP with perfusion imaging, T2-weighted imaging and DHE. Patients with SCMP typically have characteristic wall
motion defects similar to that seen in anteroapical infarction. Patients Inhibitors,research,lifescience,medical with SCMP may have small areas of subtle DHE in a pattern that is distinctly different from DHE seen in patients with myocardial fibrosis.39),40) Myocardial edema may also be present in these segments on T2-weighted images.40),41) Furthermore, Inhibitors,research,lifescience,medical a recent multicenter study using CMR demonstrated that SCMP may also present in other patterns of myocardial dysfunction, such as biventricular dysfunction, mid-ventricular dysfunction, and basal dysfunction. Patients in Inhibitors,research,lifescience,medical this study who had no DHE demonstrated complete recovery of the LV function on follow-up CMR. Cytoskeletal Signaling inhibitor However, SCMP can
be misdiagnosed as AMI, and AMI can be misdiagnosed as SCMP.42) The recent guidelines for the diagnosis of SCMP37) define this entity on the basis of acute LV apical ballooning, after exclusion of AMI. Although there is lack of agreement on the necessity of coronary angiography, either this or coronary CT is usually Inhibitors,research,lifescience,medical performed to exclude coronary occlusion. DHE-CMR may be used in the identification of the presence of a significant coronary artery disease and decrease the need of conventional Inhibitors,research,lifescience,medical coronary angiography.16) The treatment of SCMP is similar to that of ischemic LV dysfunction. However, the prognosis of SCMP is good, with rapid recovery within a week.11),37) For this reason, not only is appropriate imaging an important step to confirm the diagnosis, but follow-up imagine is often performed to confirm resolution. Endocrine
etiologies Catecholamine-induced and cardiomyopathy and pheochromocytoma Both endogenous and exogenous catecholamines have direct effects on the myocardium, including myocarditis and endocardial and myocardial hemorrhage.43) Subcutaneous injection of catecholamines and high dosage of some of sympathomimetic drugs, for example, methamphetamine, can cause catecholamine-induced cardiomyopathy.44),45) Pheochromocytoma is a well-known cause of catecholamine-induced cardiomyopathy.46) The exact incidence of pheochromocytoma is unknown, but with the recent, widespread use of CT in routine screening, its incidence as an incidental finding is increasing, and the incidence of LV dysfunction associated with pheochromocytoma remains low.