case_images: PMC11748477_01
case_images: Initial investigation. A: 12-lead ECG at first presentation, showing sinus rhythm and complete right bundle branch block. B: CCTA demonstrating a non-stenotic, non-calcified plaque, encompassing necrotic core at the ostium of the D1. C: 99mTc-SPECT-MPI with evidence of inferoseptal and anteroseptal fixed perfusion defect (arrows) and reversible perfusion defect anterobasal (arrowheads). D: Fusion of CCTA with 99mTc-SPECT-MPI-Stress showing absence of perfusion defect in the D1 territory. E: ECG at second presentation with first diagnosis of third-degree AV-Block
case_images: 10554_2024_3232_Fig1_HTML.jpg
case_images: PMC11748477_01_10554_2024_3232_Fig1_HTML.jpg
case_images: Fig1
case_images: A 12-lead ECG showed sinus rhythm with complete right bundle branch block and normal repolarization (Fig. 1A). AU) but an ostial, non-obstructive, low-attenuation plaque of the first diagonal branch (D1) (Fig. 1B). An ad-hoc, complementary, 99mTc-SPECT myocardial perfusion (99mTc-SPECT-MPI) scan demonstrated fixed inferoseptal and anteroseptal perfusion defects and a reversible anterior basal perfusion defect. Hybrid imaging with CCTA showed no correlation of the perfusion defects with the myocardium supplied by the D1 (Fig. 1C and D) and the MPI was reported as normal. Although blood pressure was normal (127/66 mmHg), he was profoundly bradycardic (40 bpm) and ECG revealed a third-degree AV-Block (Fig. 1E).
case_images: Advanced imaging. A: Cardiac MRI short axis and 2-chamber views, showing epicardial late gadolinium enhancement of the LV (anterior, anteroseptal and inferoseptal - arrowheads) and the RV free wall (arrow). B: Baseline 18F-FDG-PET/CT planar and axial images revealing multi-focal myocardial inflammation of the LV and the RV (asterisks). C: Axial fused image of cardiac MRI and baseline 18F-FDG-PET/CT, depicting matching of the epicardial fibrosis with the myocardial inflammation. D: Follow-up 18F-FDG-PET/CT, showing complete remission of the cardiac inflammation
case_images: 10554_2024_3232_Fig2_HTML.jpg
case_images: PMC11748477_01_10554_2024_3232_Fig2_HTML.jpg
case_images: Fig2
case_images: T1- and T2-mapping values (Fig. 2A). To further investigate the suspicion of sarcoidosis with cardiac involvement, the patient underwent a cardiac 18F-FDG-PET/CT (with dietary preparation with a high-fat/low-carbohydrate diet for >= 24 h, fasting for at least 12 h, as well as intravenous administration of unfractioned heparin) showing, congruent to the fibrosis areas, myocardial inflammation of the LV myocardium and the RV wall (Fig. 2B-C). At nine months follow-up, 18F-FDG-PET/CT revealed complete remission of the cardiac inflammation (Fig. 2D).
case_images: Follow-up Imaging. A: 13N-NH3-PET/CT stress/rest polar plots demonstrating an inferoseptal (fibrosis/scar; arrowhead) and a smaller anterior-basal fixed perfusion defect along with an anterior/anteriorseptal-basal reversible perfusion defect (ischemia; asterisk); and baseline 18F-FDG-PET/CT polar plot demonstrating the matched, initially inflamed myocardial regions. B: 13N-NH3-PET/CT myocardial blood flow analysis demonstrating regional (anterior/anteriorseptal) hyperemic myocardial blood flow and MFR reduction, congruent to the ischemic areas (asterisk). C: Follow-up CCTA demonstrating discrete progression of the now fibrocalcific ostial D1 lesion, causing borderline obstruction (ca. 50% luminal area stenosis). D: Fusion of follow-up CCTA with 13N-NH3-PET/CT, depicting mismatch of the abnormally perfused areas with the D1 territory
case_images: 10554_2024_3232_Fig3_HTML.jpg
case_images: PMC11748477_01_10554_2024_3232_Fig3_HTML.jpg
case_images: Fig3
case_images: The latter revealed an inferoseptal and a smaller anterior fixed perfusion defect (fibrosis/scar) along with an anterior/anteroseptal ischemia (Fig. 3A). Regional myocardial blood flow reserve (MBFR) and hyperemic myocardial blood flow (MBF) were reduced, congruent to the abnormally perfused areas, denoting possible regional microvascular dysfunction (Fig. 3B). Based on the minimal coronary calcifications at 13N-NH3-PET/CT (CAC score 5 AU), a CCTA was repeated, showing solely local progression of the ostial D1 lesion, now causing borderline obstruction (ca. 50% luminal area stenosis) (Fig. 3C). Fusion imaging demonstrated that the atherosclerotic lesion did not cause any ischemia, with the perfusion defects matching rather the fibrosis and inflammatory areas of the LV-myocardium (Fig. 3D).