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- Arnberg, Elsa, et al.
(author)
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RWT/SaVR-A Simple and Highly Accurate Measure Screening for Transthyretin Cardiac Amyloidosis
- 2022
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In: Journal of Clinical Medicine. - : MDPI. - 2077-0383. ; 11:14
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Journal article (peer-reviewed)abstract
- BACKGROUND: Cardiac amyloidosis is an underdiagnosed condition and simple methods for accurate diagnosis are warranted. We aimed to validate a novel, dual-modality approach to identify transthyretin cardiac amyloidosis (ATTR-CA), employing echocardiographic relative wall thickness (RWT), and ECG S-wave from aVR (SaVR), and compare its accuracy with conventional echocardiographic approaches.MATERIAL AND METHODS: We investigated 102 patients with ATTR-CA and 65 patients with left ventricular hypertrophy (LVH), all with septal thickness > 14 mm. We validated the accuracy of echocardiographic measures, including RWT, RWT/SaVR, posterior wall thickness (PWT), LV mass index (LVMI), left atrial volume index (LAVI), global longitudinal strain (GLS), and relative apical sparing (RELAPS) to identify ATTR-CA diagnosed using DPD-scintigraphy or abdominal fat biopsy.RESULTS: PWT, RWT, RELAPS, troponin, and RWT/SaVR were significantly higher in ATTR-CA compared to LVH. RWT/SaVR > 0.7 was the most accurate parameter to identify ATTR-CA (sensitivity 97%, specificity 90% and accuracy 91%). RELAPS was found to have much less accuracy (sensitivity 74%, specificity 76% and accuracy 73%).CONCLUSION: We can confirm the very strong diagnostic accuracy of RWT/SaVR to identify ATTR-CA in patients with septal thickness > 14 mm. Given its high sensitivity and specificity, RWT/SaVR > 0.7 has the potential to implement as a non-invasive, simple, and widely available diagnostic tool when screening for ATTR-CA.
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- Arvidsson, Sandra, 1986-, et al.
(author)
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Amyloid Cardiomyopathy in Hereditary Transthyretin V30M Amyloidosis - Impact of Sex and Amyloid Fibril Composition
- 2015
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In: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 10:11
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Journal article (peer-reviewed)abstract
- PURPOSE: Transthyretin V30M (ATTR V30M) amyloidosis is a phenotypically diverse disease with symptoms ranging from predominant neuropathy to exclusive cardiac manifestations. The aims of this study were to determine the dispersion of the two types of fibrils found in Swedish ATTR V30M patients -Type A consisting of a mixture of truncated and full length ATTR fibrils and type B fibrils consisting of full length fibrils, and to estimate the severity of cardiac dysfunction in relation to fibril composition and sex.MATERIAL AND METHODS: Echocardiographic data were analysed in 107 Swedish ATTR V30M patients with their fibril composition determined as either type A or type B. Measurements of left ventricular (LV) dimensions and evaluation of systolic and diastolic function including speckle tracking derived strain were performed. Patients were grouped according to fibril type and sex. Multivariate linear regression was utilised to determine factors of significant impact on LV thickness.RESULTS: There was no significant difference in proportions of the two types of fibrils between men and women. In patients with type A fibrils, women had significantly lower median septal (p = 0.007) and posterior wall thicknesses (p = 0.010), lower median LV mass indexed to height (p = 0.008), and higher septal strain (p = 0.037), as compared to males. These differences were not apparent in patients with type B fibrils. Multiple linear regression analysis revealed that fibril type, sex and age all had significant impact on LV septal thickness.CONCLUSION: This study demonstrates a clear difference between sexes in the severity of amyloid heart disease in ATTR V30M amyloidosis patients. Even though type A fibrils were associated with more advanced amyloid heart disease compared to type B, women with type A fibrils generally developed less cardiac infiltration than men. The differences may explain the better outcome for liver transplanted late-onset female patients compared to males.
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- Fertner, Antoni, et al.
(author)
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Applications of Backscattering for the Study of Twisted Pair Transmission Lines
- 2018
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In: IEEE Transactions on Microwave Theory and Techniques. - 0018-9480. ; 66:12, s. 5230-5237
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Journal article (peer-reviewed)abstract
- The phenomenon of backscattering in copper cables has been recently observed and initially explicated. It can provide promising techniques to address the problem of loop diagnostic and maintenance. The backscattering is analyzed both in frequency and time domains. To demonstrate the practical use of the phenomenon, we estimate certain properties of the loop using wideband, high-frequency $\selevenf(f)$ measurements performed in the laboratory on real cables. The results corroborate the usefulness and accuracy of the investigated method.
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- Fertner, Antoni, et al.
(author)
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Backscattering in Twisted-Pair Nonhomogeneous Transmission Lines
- 2018
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In: IEEE Transactions on Microwave Theory and Techniques. - 0018-9480. ; 66:6, s. 2674-2682
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Journal article (peer-reviewed)abstract
- The development of the communication networks tends gradually toward exploiting higher frequencies, sometimes even reaching the lowest microwave band (P-band). As the signal bandwidth used for transmission over twisted-pairs increases, as recommended by G.fast and other broadband systems, new phenomenon was observed, namely, backscattering. Motivated by the measurements of copper cables in frequency band up to 400 MHz, we propose a novel backscattering model. It may be productively applied to the problem of loop diagnostics. The methods to accurately and reliable determine the relevant transmission-line parameters are sine qua non condition to appropriately exploit the potential of short-to-medium range access lines. In this paper, a recursive formulation of the frequency-domain response of the backscattering is used for a space-time characterization. To confirm the practical use of the finding, we evaluate the properties of a loop using wideband, high-frequency S₁₁ measurements of the real cables. These laboratory results confirm the effectiveness and accuracy of the proposed method.
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- Gustafsson, Sandra, et al.
(author)
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Amyloid Fibril Composition as a Predictor of Development of Cardiomyopathy After Liver Transplantation for Hereditary Transthyretin Amyloidosis
- 2012
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In: Transplantation. - 0041-1337 .- 1534-6080. ; 93:10, s. 1017-1023
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Journal article (peer-reviewed)abstract
- Background. Liver transplantation (LTx) is an accepted treatment for hereditary transthyretin (TTR) amyloidosis (ATTR). However, unforeseen heart complications, especially a rapid development of cardiomyopathy after LTx has affected mortality and morbidity. Recently, a relationship between ATTR-fibril composition and cardiomyopathy has been noted. The aim of this study was to investigate whether development of cardiomyopathy and heart failure in LTx ATTR amyloid patients is related to amyloid fibril composition.Methods. Twenty-four patients with hereditary ATTR amyloidosis who had undergone LTx and have had their amyloid fibril type tested were available for the study. They had been examined by echocardiography including tissue Doppler and speckle tracking echocardiography before and after LTx. Patients were divided into two groups according to fibril composition, 10 patients with type A fibrils (a mixture of truncated and full-length TTR) and 14 patients with type B fibrils (full-length TTR fibrils only). There was no difference in time to the follow-up echocardiography between the two groups.Results. After LTx, the group consisting of type A patients developed symptoms of heart failure and with reduced systolic and diastolic ventricular function as shown by echocardiography, whereas no similar deterioration was noted for the group of patients with type B fibrils.Conclusion. Patients with type A fibrils deteriorate an already existing cardiomyopathy and heart failure after LTx, in contrast to patients with type B fibrils. These results might have significant clinical implications in optimizing best patients selection criteria for LTx.
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- Henein, Michael Y., et al.
(author)
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Reduced left atrial myocardial deformation irrespective of cavity size : a potential cause for atrial arrhythmia in hereditary transthyretin amyloidosis
- 2018
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In: Amyloid. - : TAYLOR & FRANCIS LTD. - 1350-6129 .- 1744-2818. ; 25:1, s. 46-53
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Journal article (peer-reviewed)abstract
- Background: Cardiac amyloidosis (CA) is a myocardial disease and commonly under-diagnosed condition. In CA patients, atrial fibrillation might occur in the absence of left atrial (LA) enlargement.Objectives: The aim of this study is to assess LA size and function, and its relationship with atrial arrhythmia in patients with hereditary transthyretin amyloidosis (ATTR).Methods: Forty-six patients with confirmed ATTR amyloidosis on abdominal biopsy were studied. Assessment with 2D echocardiography and 2D strain showed 31 patients had increased LV wall thickness (LVWT) (septal thickness >12mm), and 15 had normal LVWT. In addition to conventional measurements, LV and LA global longitudinal strain (GLS%) and strain rate (SR) were obtained. Western blot analysis was done to assess fibril type. ATTR patients with increased LVWT were compared with 23 patients with hypertrophic cardiomyopathy (HCM) and 31 healthy controls. ATTR amyloidosis patients also underwent 24hour Holter monitoring to determine the presence of atrial arrhythmia.Results: Atrial deformation during atrial systole was reduced in ATTR amyloidosis patients with increased LVWT independent of LA size and in contrast to HCM. Twenty of the ATTR amyloidosis patients (54%) had ECG evidence of significant atrial arrhythmic events. LA strain rate, during atrial systole, was the only independent predictor of atrial arrhythmia (=3.28, p=.012).Conclusion: In ATTR cardiomyopathy with increased LVWT, LA myocardial function is abnormal, irrespective of atrial cavity size. Reduced LA myocardial SR during atrial systole, irrespective of cavity volume, E/e and LV deformation, is also a strong predictor for atrial arrhythmic events.
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