Presentation
Peripheral neuropathy, thickened septum with granular sparkling on echocardiography.
Patient Data
Heart rate: 65-80 bpm, haematocrit: 0.38
Image quality: some artifacts
Morphology and functional analysis (endo-volume):
LV-EDVI: 108 mL/m²
LV-ESVI: 55 mL/m²
LV-SVI: 53 mL/m²
LV-EF: 49%
cardiac output: 7.6 L/min
cardiac index: 3.9 L/min/m²
LV-ED wall mass index (without papillary muscle): 88 g/m²
septum thickness: 18 mm
Findings:
global hypokinesia; abnormal diastolic relaxation
increased left and right atria
mildly thickened atrial septum and right atrial wall
mitral and tricuspid insufficiency
no intracavitary thrombi
Myocardial tissue properties:
Mildly increased signal of the cardiac septum indicating myocardial oedema.
Difficulties in nulling the myocardium with the look locker sequence: the late gadolinium 4-chamber view was repeated.
PSIR and IR-GE sequences show a dark blood pool and delicate subendocardial late gadolinium enhancement in a diffuse, non-coronary distribution with emphasis on the basal segments and the right ventricle e.g. right ventricular septal subendocardium.
T1 mapping native: 1100-1180 ms (z-score: 3-6)
extracellular volume (ECV): >40% (up to 60% in the basal anteroseptal segment)
T2 mapping: 56-58 ms (z-score: 2-3) in the midventricular septal segments
Normal reference ranges based on local data:
native T1: 940-1060 ms; ECV: <32%; T2: 44-56 ms
No pericardial enhancement. Minimal pericardial effusion.
Impression:
non-obstructive left ventricular hypertrophy with mild systolic dysfunction
cardiac MRI findings are consistent with cardiac amyloidosis
the values in native T1 (z-score: 3-6), the extracellular volume (ECV) and the distinct thickening of the interventricular septum favour ATTR over AL cardiac amyloidosis
Image courtesy: Kirsten Fleckstein (imaging technologist)
The blood pool image shows a significant accumulation of the heart muscle.
The whole-body late image also shows a significant accumulation of the heart, which exceeds the intensity of the ribs (corresponding to a Perugini score of 3).
Impression
Scintigraphic evidence of ATTR amyloidosis with cardiac involvement (Perugini score 3).
Courtesy: Dr Juliane Mehler, Dr Johannes Dvorak (nuclear physicians)
Due to the high price of drug therapy, the patient had a myocardial biopsy with the biopsy samples taken from the right ventricular outflow tract which initially did not show any abnormalities and did.
A repeat cardiac MRI after 6 months (not shown) did not show any substantial change.
The myocardial biopsy was repeated at the patient's request and biopsy samples were taken from the left ventricular myocardium.
Histology
Detection of diffuse and focal cardiac amyloid, which occupies approx. 65% of the total area of the specimen, with immunohistochemically detectable cardiac ATTR amyloidosis presumably ATTR wild-type. No haemochromatosis, glycogenosis or Fabry disease. No evidence of acute or chronic myocarditis.
Impression: cardiac ATTR amyloidosis, most likely ATTR wild-type
Genotyping
Subsequent genotyping confirmed the diagnosis of wild-type ATTR amyloidosis.
Case Discussion
A case of cardiac amyloidosis with typical MR features and mildly reduced systolic function.
The diffuse subendocardial late gadolinium enhancement and abnormal gadolinium kinetics suggested the diagnosis supported by the increased extracellular volume 1-3.
The moderately increased native T1 values (z-score: 3-6), the significantly elevated extracellular volume and the thickened interventricular septum favoured ATTR over AL cardiac amyloidosis in the cardiac MRI already and the diagnosis was supported by a Perugini score of 3 on bone scintigraphy and the absence of free light chains in the serum and negative serum and urine immunofixation test.
An initially negative myocardial biopsy could also be conclusively refuted by a repeat myocardial biopsy and the patient is now on his treatment regimen.
Co-authors: Dr Juliane Mehler and Dr Joannes Dvorak (nuclear physicians)
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