Discussion:
Over its clinical course, IE can destroy large areas of tissue in the aortic annulus, reducing the strength and stability of native cardiac tissue while simultaneously increasing the risk of LV-Ao discontinuity. Extensive debridement of infected cardiac structures prior to valve replacement further adds to risk of discontinuity because it decreases the amount of available healthy tissue available for restructuring and repair of the LVOT.3 The avascular nature of the mitral aortic intervalvular fibrosa (MAIVF) in the LVOT makes it susceptible to infection and abscess formation in the setting of aortic valve and root endocarditis. Aortic valve regurgitation in the setting of aortic valve endocarditis may also contribute to MAIVF pseudoaneurysm formation, as the infected regurgitation jets hit the inherently susceptible MAIVF. In the setting of IE, Staphylococcus species are the most implicated cause of abscess and pseudoaneurysm formation.4 After surgical correction, follow up by TTE can assess prosthetic valve function but may be insufficient to diagnose new abscesses or pseudoaneurysms. In such cases, other imaging modalities, such as ECG-gated CT or magnetic resonance imaging, can improve sensitivity and accuracy in diagnosis of these complications. As LVOT pseudoaneurysms and complete discontinuity may present with nonspecific signs and symptoms such as heart failure and chest pain, advanced cross section imaging should be considered early.5,6 LVOT pseudoaneurysms carry high risk of rupture and subsequent sudden cardiac death with a frequency of up to 50%. TTE has been shown to be an ineffective modality for diagnosing LVOT pseudoaneurysm and discontinuity.4,5,7,8 In a previously published review, definitive diagnoses by TTE were achieved only in 36% of cases and missed up to 65% of the time.4 Transesophageal echocardiography can increase the sensitivity and specificity for diagnoses of such lesions. Cardiac computed tomography, as exemplified in this case, provides higher sensitivity than TTE and better 3-dimensional assessment of the lesion.4,5