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Background: Recent studies have reported atrial involvement and coexistence of aortic stenosis in transthyretin (ATTR) cardiac amyloidosis (CA). However, pathological reports of extraventricular ATTR amyloid deposits in atrial structures or heart valves are limited, and the clinical implications of ATTR amyloid deposits outside the ventricles are not fully elucidated. Case presentation: We report 3 cases of extraventricular ATTR amyloid deposits confirmed in surgically resected aortic valves and left atrial structures, all of which were unlikely to have significant ATTR amyloidosis infiltrating the ventricles as determined by multimodality evaluation including 99mtechnetium-pyrophosphate scintigraphy, cardiac magnetic resonance, endomyocardial biopsy and their mid-term clinical course up to 5 years. These findings suggested that these were extraventricular ATTR amyloid deposits localized in the aortic valve and the left atrium. Conclusions: While long-term observation is required to fully clarify whether these extraventricular ATTR amyloid deposits are truly localized outside the ventricles or are early stages of ATTR-CA infiltrating the ventricles, our 3 cases with multimodality evaluations and mid-term follow up suggest the existence of extraventricular ATTR amyloid deposits localized in the aortic valve and left atrial structures. [ABSTRACT FROM AUTHOR]

Abstract We present not‐yet‐seen multimodal images of a 55‐year‐old female patient with isolated atrial amyloidosis (IAA) who clinically suffered from multiple atrial arrhythmias and heart failure symptoms with preserved left ventricular ejection fraction. We aim to show structural and functional abnormalities detected by electrophysiological voltage mapping, cardiac magnetic resonance imaging (MRI) [cMRI; atrial strain measurements, late gadolinium enhancement (LGE) visualization], and 99mTc‐DPD scintigraphy. Bipolar voltage mapping performed during two electrophysiological procedures showed diffuse left atrial low‐voltage areas (bipolar

We present not‐yet‐seen multimodal images of a 55‐year‐old female patient with isolated atrial amyloidosis (IAA) who clinically suffered from multiple atrial arrhythmias and heart failure symptoms with preserved left ventricular ejection fraction. We aim to show structural and functional abnormalities detected by electrophysiological voltage mapping, cardiac magnetic resonance imaging (MRI) [cMRI; atrial strain measurements, late gadolinium enhancement (LGE) visualization], and 99mTc‐DPD scintigraphy. Bipolar voltage mapping performed during two electrophysiological procedures showed diffuse left atrial low‐voltage areas (bipolar < 0.5 mV) and also a moderately diseased right atrium suspected of infiltrative cardiomyopathy. Catheter ablation did successfully treat a left atrial and two right atrial focal tachycardias. For further diagnostics, a 3T cMRI was performed, revealing a subendocardial circumferential left atrial LGE and pathological atrial strain measurements, especially during conduit and reservoir phase. Afterwards, nuclear imaging with 559 MBq of 99mTc‐DPD was performed. The scan revealed amyloid infiltration of the left atrium. Neither an uptake in the ventricular myocardium nor an extra‐cardiac uptake of DPD was seen. Genetic testing for transthyretin amyloidosis mutations in this patient was negative, and peripheral neuropathy was ruled out by electromyogram analysis. The synopsis of these findings reveals IAA as the most possible diagnosis and showed isolated atrial nuclear tracer uptake with 99mTc‐DPD scintigraphy for the first time. Non‐invasive imaging techniques might help in suggesting IAA but need further investigation. [ABSTRACT FROM AUTHOR]

Heart failure with preserved ejection fraction (HFpEF) and atrial fibrillation (AF) are very common conditions, particularly in the elderly. However, the mechanisms underlying the two disorders, including their intricate interaction have not been fully resolved. Here, our aim is to review the evidence on the role of the two types of senile amyloidosis in this connection. Two types of senile amyloidosis can be identified: wild-type transthyretin (TTR)-derived amyloidosis (ATTRwt) and isolated atrial amyloidosis (IAA). ATTRwt is an underlying condition that is being increasingly recognized in patients with HFpEF and often accompanied by AF. IAA is an established cause of AF, adding to the mechanism problem. New diagnostic and therapeutic possibilities have emerged that may facilitate clinical management of (senile) amyloidosis, which in turn may have implications for the management of HFpEF and AF. View large Download slide View large Download slide [ABSTRACT FROM AUTHOR]

The myocardium of the right and left atrial appendages (auricles) in patients with paroxysmal, persistent, and permanent forms of atrial fibrillation was examined by histological methods and electron microscopy. Isolated atrial amyloidosis was detected in the left (50.0-56.3% patients) and in the right (45.0-55.6% patients) atrial appendages. In all cases, immunohistochemistry revealed atrial natriuretic peptide in fibrillary amyloid deposits. Ultrastructurally, amyloid masses formed clusters of myofibrils 8-10 nm in diameter. They were chaotically located in the extracellular space along the sarcolemma as well as in membrane invaginations, dilated tubules of cardiomyocyte T -tubular system, and vascular walls. Amyloidosis was predominantly observed in women; its degree positively correlated with age of patients and duration of atrial fibrillation but negatively correlated with atrial fibrosis. The study revealed positive (in permanent atrial fibrillation) and negative (in paroxysmal atrial fibrillation) correlation of amyloidosis with myofibril content in atrial cardiomyocytes. [ABSTRACT FROM AUTHOR]

Objectives: Diffuse cardiac amyloidosis is a significant diagnosis with a poor prognosis. Isolated atrial amyloidosis (IAA) is the most common form of cardiac amyloidosis caused by accumulation of alpha-atrial natriuretic peptide. IAA has been associated with dysrhythmia, but otherwise remains a poorly characterized condition. The impact of incidental IAA on postoperative outcome following cardiac surgery has not previously been reported. The purpose of this study was to examine the impact of isolated atrial amyloid on patient outcomes following cardiac surgery., Methods: A retrospective analysis was performed of all patients having excision of the left atrial appendage during cardiac surgery at our centre over a 5-year period. Patients with histological evidence of IAA were compared to patients without this diagnosis. IAA was diagnosed by immunohistochemistry for atrial natriuretic peptide., Results: A total of 167 patients underwent left atrial appendage excision and of these 26 (15.6%) were found to have IAA. Preoperative characteristics were similar between the 2 groups. A significantly greater proportion of patients with IAA experienced dysrhythmia requiring implantation of a permanent pacemaker (23.1% vs 7.8%, P = 0.03). There was also a significantly elevated incidence of perioperative death in the IAA group (11.5% vs 1.4%, P = 0.03) and inferior 1-year survival (84.6% vs 96.5%, P = 0.02)., Conclusions: The presence of IAA may be associated with inferior outcomes following cardiac surgery, with increased morbidity in the early postoperative period and inferior long-term survival. Knowledge of the diagnosis preoperatively may facilitate management of patients., (© The Author(s) 2019. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)

Heart failure with preserved ejection fraction (HFpEF) and atrial fibrillation (AF) are very common conditions, particularly in the elderly. However, the mechanisms underlying the two disorders, including their intricate interaction have not been fully resolved. Here, our aim is to review the evidence on the role of the two types of senile amyloidosis in this connection. Two types of senile amyloidosis can be identified: wild-type transthyretin (TTR)-derived amyloidosis (ATTRwt) and isolated atrial amyloidosis (IAA). ATTRwt is an underlying condition that is being increasingly recognized in patients with HFpEF and often accompanied by AF. IAA is an established cause of AF, adding to the mechanism problem. New diagnostic and therapeutic possibilities have emerged that may facilitate clinical management of (senile) amyloidosis, which in turn may have implications for the management of HFpEF and AF., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2019. For permissions, please email: journals.permissions@oup.com.)

Isolated atrial amyloidosis (IAA) is a common localized form of amyloid deposition within the atria of the aging heart. The main constituents of amyloid fibrils are atrial natriuretic peptide (ANP) and the N-terminal part of its precursor form (NT-proANP). An 'aggregation-prone' heptapeptide ((114)KLRALLT(120)) was located within the NT-proANP sequence. This peptide self-assembles into amyloid-like fibrils in vitro, as electron microscopy, X-ray fiber diffraction, ATR FT-IR spectroscopy and Congo red staining studies reveal. Consequently, remedies/drugs designed to inhibit the aggregation tendency of this 'aggregation-prone' segment of NT-proANP may assist in prevention/treatment of IAA, congestive heart failure (CHF) or atrial fibrillation (AF)., (Copyright © 2013 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.)