PMC5348457_01
The results of the physiological examinations. (A) Chest radiography reveals cardiomegaly (cardiothoracic ratio, 59%) and mild pulmonary congestion. (B) An electrocardiogram reveals a prominent R wave progression in V3-6 and a negative T wave in V5-6. (C, D) Transthoracic echocardiograms reveal the thickening of the left and right ventricle walls. The left ventricle ejection fraction is 40%.
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Chest radiography revealed an increase in the cardiothoracic ratio (59%) and mild pulmonary congestion (Fig. 1A). T wave in the left lateral precordial leads (Fig. 1B). Transthoracic echocardiography detected thickening of the LV walls (septum, 16 mm; posterior wall, 16 mm), as well as thickening of the right ventricle (RV) free wall, the slight dilatation of the LV (LV end-diastolic diameter, 54 mm) and diffuse LV systolic dysfunction (ejection fraction, 40%; using Simpson's method) (Fig. 1C and D). The pressure gradient of the tricuspid regurgitation was 47 mmHg.
The histopathological findings. (A) A light microscopy image reveals interstitial fibrosis and hypertrophic myocytes with vacuoles (Elastica-Masson staining, 100x). (B) An electron microscopy image reveals an increased number of mitochondria with variable sizes and shapes.
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The microscopic findings revealed the rupture and degeneration of the myocardial fibers, which were surrounded by fibrosis(Fig. 2A). Electron microscopy detected an increase in the number of mitochondria, which varied in size and morphology (Fig. 2B).
Cardiac scintigraphy and cardiac magnetic resonance imaging. (A) The uptake of 99mTc-MIBI is not decreased in the early phase. (B) The uptake of 123I-BMIPP is decreased in the anterior, septal, and inferior walls. (C) Late gadolinium enhancement (LGE) is observed from the midmyocardium to the epicardium of the anterior wall, as well as in the midmyocardium of the septal and inferior walls. (D) Bull's eye mapping shows the 99mTc-MIBI/123I-BMIPP mismatch pattern (non-decreased 99mTc-MIBI uptake/decreased 123I-BMIPP uptake). 99mTc-MIBI: technetium-99m methoxyisobutylisonitrile. 123I-BMIPP: 123-labeled 15-4-iodophenyl-3-(R, S)-methyl-pentadecanoic acid.
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In the early phase, the uptake of 99mTc-MIBI did not decrease (Fig. 3A). The uptake of 99mTc-MIBI in the RV free wall appeared to be enhanced in the early phase (Fig. 3A). 123I-BMIPP (111 MBq) was administered intravenously, and SPECT images were obtained at 35 minutes after the injection. The uptake of 123I-BMIPP was decreased in the anterior, septal, and inferior walls (Fig. 3B). CMR was performed to estimate late gadolinium enhancement (LGE), which was observed from the midmyocardium to the epicardium of the anterior wall, as well as in the midmyocardium of the septal and inferior walls (Fig. 3C). The 99mTc-MIBI/123I-BMIPP mismatch pattern (non-decreased 99mTc-MIBI uptake/decreased 123I-BMIPP uptake) was confirmed via bull's eye mapping (Fig. 3D).