IJCS | Volume 32, Nº2, March/April 2019

178 Ribeiro et al. CMR and amyloidosis Int J Cardiovasc Sci. 2019;32(2)177-189 Review Article Based on these considerations, this study aimed to present current concepts of amyloidosis and the use of CMR in the diagnosis and follow-up of these patients. We conducted a bibliographic review on Pubmed (National Library of Medicine) database, using the terms “amyloidosis”, “disease, myocardial” and “magnetic resonance imaging” for the search. Results A total of 135 articles were retrieved, and 60 were selected for being published in higher impact journals and consensus of the authors.We summarized current concepts of amyloidosis types, diagnostic methods, prognosis and treatment of the disease in the following text. Discussion Main types of amyloidosis Two types of amyloidosis can affect the myocardial ventricle: immunoglobulin light chain amyloidosis and transthyretin amyloidosis, which, in turn, has two forms of presentation – wild type and genetically variant transthyretin amyloidosis. Immunoglobulin light chain Light chain amyloidosis, also known as primary systemic amyloidosis, is the most common type of amyloidosis. This is a plasma cell dyscrasia characterized by deposition of amyloidogenic chains in the extracellular space, causing a lesion in this tissue affected. Cardiac dysfunction is seen in up to 50% of patients with amyloidosis, 9 and this type of amyloidosis can cause restrictive cardiomyopathy. Congestive heart failure is quite common, caused by thickening and lack of dilatation of the left ventricle, detected by echocardiography. 10 Myocardial dysfunction caused by amyloidosis can be evaluated by measurement of brain natriuretic peptide (BNP) and troponin levels. Right heart failure is frequently aggravated by the concomitant presence of nephrotic syndrome, observed in 30-50% of the cases. Cardiomyopathy is the most aggressive manifestation of amyloidosis, and the main cause of poor prognosis and death. Cardiac amyloidosis has also been associated with multiple myeloma, which can also be evaluated. 2,9,11,12 Hereditary Systemic Amyloidosis Hereditary systemic amyloidosis is a dominant autosomal disease caused by deposition of amyloid fibrils resulting from mutations in genes that encode transthyretin and apolipoprotein A-I, A-II, fibrinogen, gelsolin, cystatin C and lysozyme. Transthyretin is mainly produced by the liver and participates in the transport of thyroxine and retinol. Hereditary systemic amyloidosis is caused by 100 different mutations in the DNA of transthyretin, generating a heterogeneity of penetrance. Clinical presentation of the disease includes cardiomyopathy, nephropathy and neuropathy. Although transthyretin-related cardiac amyloidosis is less aggressive than immunoglobulin light chain amyloidosis, hereditary systemic amyloidosis is also a cause of significant symptoms of heart failure. 13,14 Senile systemic amyloidosis Senile systemicamyloidosis, alsorelatedto transthyretin, is not hereditary and generally occurs after the seventh decade of life. This presentation of amyloidosis can be called as senile systemic or wild type amyloidosis. Similar to other types of the disease, in senile systemic amyloidosis, amyloid deposition can occur in several tissues such as cardiac, hepatic, and pancreatic tissues. Senile systemic amyloidosis is usually preceded by heart failure approximately 3-5 years before. Patients aremostly men, older than 70 years. The diagnosis of the disease had been probably underestimated; with advances in the diagnosis provided by CMR, from 2000 to 2009, the number of patients seen at amyloidosis centers in the United Kingdom increased by approximately 6.5%. 5-9,15 Recent reports have described cases of senile amyloidosis in patients with heart failure with increased ejection fraction, highlighting the importance of clinical cardiologists considering the disease in suspected cases. Clinical suspicion is higher in cases of heart failure with increased ejection fraction associated with infiltrative cardiomyopathy revealed by cardiac imaging tests. 16 Other diagnostic methods Electrocardiography In amyloidosis patients, particularly in those with light chain amyloidosis, electrocardiography usually reveals low voltage of the QRS complexes which, together with