論文ID: CJ-20-1248
A 64-year-old woman suffering from dyspnea upon exertion was referred to hospital. Transesophageal echocardiography revealed a discrete membranous structure at the left ventricular outflow tract (LVOT) with a mean gradient of 58 mmHg (Figure A-1). Color Doppler imaging showed significant flow acceleration with turbulence, beginning at the level of the subaortic ridge (Figure A-2). The diagnosis was established to be discrete subaortic stenosis (DSS). The obtrusive discrete membrane was completely resected (Figure B), and postoperative echocardiography showed decreased stenotic turbulence in the LVOT (Figure C-1,2). Time-resolved 3D magnetic resonance imaging (4D-flow MRI) showed turbulent flow at the LVOT and a substantial vortex flow with an eccentric jet flow during systole before surgery (Figure D-1,2; Supplementary Movie 1). After surgery, the vortex flow and eccentric flow jet were diminished on 4D-flow MRI (Figure E-1,2; Supplementary Movie 2). In addition, regional wall shear stress (WSS) and flow energy loss (EL) also decreased significantly with surgery, from 51 to 34Pa and from 22.3 to 9.3 mW, respectively (Figure F,G). The patient remained symptom-free for 2 years after surgery. This is the first description of the blood flow changes evaluated by 4D-flow MRI for a patient with DSS after successful surgery. We hope that analyzing blood flow using 4D flow MRI will become popular in the future, because we believe that further accumulation of knowledge on hydrodynamic indicators, such as EL and WSS, and prognosis will clarify the more appropriate timing of surgery and thus improve the prognosis of congenital heart disease.
(A-1,2) Preoperative transesophageal echocardiography showing a crescent-shaped membrane encircling the LV outflow tract (arrowhead). (B) Resected specimen of the crescent-shaped fibrous membrane. (C-1,2) Postoperative transthoracic echocardiography. (D,E) 3D streamline visualization of blood flow provided by 4D-flow MRI before (D-1,2) and after (E-1,2) surgery. Turbulent flow caused stenosis (arrow) and a substantial vortex flow (dotted line and curved arrow). (F,G) Comparison of wall shear stress before (F) and after (G) surgery.
T.A., T.N. are members of Circulation Journal’s Editorial Team.
Supplementary Movie 1.
Supplementary Movie 2.
Please find supplementary file(s);
http://dx.doi.org/10.1253/circj.CJ-20-1248
