Development of a Cardiac Neocavity After Mechanic Double-Valve Replacement
Evaluation by Cardiac Magnetic Resonance Imaging
A 57-year-old woman presented with signs of recurrent right ventricular congestion and dyspnea. She had a history of mechanic aortic and mitral valve replacement resulting from acute endocarditis 7 years ago. At that time, endocarditis resulted in destruction of the aortic-mitral fibrous curtain and part of the left ventricular (LV) outflow tract, rendering implantation of prosthetic valves difficult. The cuffs of both prosthetic valves were sutured together directly to ensure stable fixation.
Current echocardiographic evaluation revealed good LV contraction, normal function of the mechanic valves, and normal diameters of both ventricles. An arterially supplied neocavity was found between both atria (Figure 1). Transesophageal echocardiography suggested a dehiscence of the aortic valve sutures, resulting in blood flow between the aortic root and the neocavity (Movie I). However, further echocardiographic evaluation was limited by ultrasonic extinction caused by the prosthetic valves.
Cardiac MR cine imaging (1.5 T, Magnetom Vision, Siemens) allowed detailed evaluation of the complex anatomical findings. The neocavity was located between both atria and extended from the superior vena cava to the diaphragm in the craniocaudal orientation (Figure 2). A main finding was that the neocavity was supplied by a large opening of 1.5 cm2 located caudal to the aortic and medial to the mitral valve prosthesis. The systolic increase in size of the neocavity suggested unrestricted blood flow between the LV and the neocavity (Movies II and III). Furthermore, a small, predominately diastolic jet was seen originating from the supravalvular aortic root (Movie III), confirming the suture dehiscence seen on transesophageal echocardiography. Three-dimensional reconstruction of contrast-enhanced T1-weighted FLASH images enabled excellent visualization of the neocavity relative to surrounding cardiovascular structures (Movie IV). Despite recurrent cardiac failure, the patient refused surgical repair and was discharged after recompensation and medical therapy.
The online-only Data Supplement, which contains Movies I through IV, is available at http://circ.ahajournals.org/cgi/content/full/112/13/e238/DC1.