Diagnostic strategies for symptomatic transthyretin (ATTR) cardiac amyloidosis showing typical morphological features such as increased ventricular wall thickness and myocardial injury such as an elevation in serum troponin T level have been established, but those for subclinical cardiac amyloidosis are limited. In the era when effective therapies to suppress/delay progression of ATTR cardiac amyloidosis are available, early detection of cardiac involvement plays a crucial role in appropriate decision-making for treatment in TTR mutation carriers who have a family history of heart failure and death due to ATTR amyloidosis. Findings of three cases with known pathogenic transthyretin (TTR) mutations (p.Ser70Arg, p.Phe53Val, and p.Val50Met) and family histories of death for amyloidosis were presented. Two cases were asymptomatic, and a case carrying p.Phe53Val had gastrointestinal symptoms and autonomic neuropathy. Levels of plasma N-terminal fragment of pro-B-type natriuretic peptide and troponin T were within normal ranges in all cases, but results of cardiac magnetic resonance (CMR) and bone scintigraphy clearly revealed the presence of cardiac involvement in all cases, even in a case without echocardiographic abnormalities including left ventricular hypertrophy and relative apical sparing of longitudinal strain shown by two-dimensional speckle-tracking echocardiography. Electrocardiography revealed modest abnormalities including reduced R wave amplitude in V2 and a trend toward left axis deviation in all cases. In conclusion, CMR, bone scintigraphy, and electrocardiography are useful for early detection of ATTR cardiac amyloidosis in TTR mutation carriers. The role of comprehensive cardiac assessment in the early detection of cardiac amyloidosis in TTR mutation carriers is discussed.
Background: The effects of L-carnitine on the hemodynamic state of chronic hemodialysis patients have been debated. In order to clarify the effect of administered L-carnitine on cardiac function and hypotensive episodes during the hemodialysis procedure, a randomized double-blind placebo-controlled study was performed for 3 months. Methods and Results: Twenty stable outpatients undergoing hemodialysis treatment were divided into two groups: controls (placebo) and treated patients (L-carnitine 900 mg p.o. daily). After 3 months, cardiac function was reevaluated by echocardiography, and hypotensive episodes during hemodialysis were assessed. Free and acyl carnitine levels increased significantly from 22.3 ± 7.1 to 140.3 ± 57.5 μmol/l and from 15.8 ± 2.8 to 94.8 ± 50.4 μmol/l, respectively, in the treated group. The ejection fraction significantly increased from 61.8 ± 16.0 to 64.4 ± 13.8% (p < 0.05) in the treated group. However, there was no difference in other echocardiographic parameters between the two groups. Hypotensive episodes significantly decreased from 4.0 ± 1.7 to 1.3 ± 0.9 times per month (p < 0.05), although patients' body weight did not change significantly. Conclusions: Beneficial effects of L-carnitine on the hemodynamic state of chronic hemodialysis patients were observed. L-Carnitine supplementation might be considered especially for chronic hemodialysis patients with unstable hemodynamic conditions.
