Noninvasive Diagnostic Modalities in an Isolated Case of Cardiac Amyloidosis

Amyloidoses are a family of inherited or acquired disorders characterized by the deposition of insoluble extracellular protein fibrils in various organs and tissues, thereby impairing their function. Amyloidoses are typically misfolded proteins, and on rare occasions, can deposit in the myocardium resulting in an infiltrative/restrictive cardiomyopathy. Restrictive cardiomyopathy is an underdiagnosed cause of congestive heart failure (CHF) with preserved ejection fraction, atrial and ventricular arrhythmias along with conduction defects. In elderly patients, as with this study, cardiac amyloidosis most often results from abnormalities in the liver protein transthyretin (TTR), a thyroxine and retinol-retinol binding complex transporter in blood. Mutated serum TTR results in familial systemic amyloidosis, whereas wild-type TTR results in senile cardiac amyloidosis predominantly seen in elderly males. Scintigraphy, a common non-invasive method used to facilitate early diagnosis of cardiac amyloidosis was the method used in this study. However, the gold standard for definitive diagnosis of cardiac amyloidosis is endomyocardial biopsy (EMB). Besides organ transplant, which is rarely done, therapy for cardiac amyloidosis is mainly aimed at symptomatic and supportive care. Plenty of evidence has shown that the left ventricular ejection fraction (LVEF) in patients with restrictive cardiomyopathy is usually preserved. However, in this study, we review the unique case of an 82-year-old male who was diagnosed with isolated cardiac amyloidosis with severe systolic dysfunction (decreasedLVEF), the methods used to establish the diagnosis, as well as the therapeutic interventions.