To be updated...
Abstract: The mitral–aortic intervalvular fibrosa (MAIVF) 1 is a region of the heart that connects the anterior mitral leaflet to the posterior aortic root and is in communication with the left ventricular (LV) outflow tract, this area contains fibrous, relatively avascular tissue and is the weakest area of the aortic ring. As a consequence of its poor vascularization, this structure is susceptible to injury during aortic or mitral valve replacement or destruction from bacterial infective endocarditis leading to development of an aneurysm or pseudoaneurysm of intervalvular fibrosa (P-MAIVF). This condition is rare in pediatric age group and is usually preceded by aortic valve surgery, active or prior infective endocarditis, and congenital heart disease Case Report: A 7-year old girl previously healthy was referred for evaluation of murmur and abnormal electrocardiogram which was suggestive of biventricular hypertrophy. Transthoracic echocardiogram (TTE) revealed a pulsatile aneurysmal structure (1.1/0.8 cm) posterior to the aortic root and extending to the mitral valve in the intervalvular mitral-aortic fibrosa. There was turbulent flow on color Doppler, filling and expanding the structure during systole and emptying during diastole. (Fig 1). There was no mitral or aortic regurgitation. A cardiac MRI was performed which confirmed the findings of echocardiogram. Her case was discussed with the pediatric cardio-thoracic surgeons and since she was asymptomatic, and her aneurysm size was deemed small, not compressing on adjacent structures or causing regurgitation, it was decided to manage the aneurysm conservatively. She has been followed up for 4 years now with mild increase in her aneurysm to 1.7/1.4 cm. Discussion: We present a congenital mitral-aortic intervalvular fossa aneurysm in a previously healthy 7 year old without any preceding event which reflects a truly congenital nature of the aneurysm. Clinical manifestation may vary from being asymptomatic to shortness of breath, congestive heart failure, cerebral vascular accidents or other embolic events, chest pain, active endocarditis infection. Enlargement of the aneurysm may lead to aortic or mitral regurgitation secondary to failure of leaflet coaptation, compression of adjacent structures including the left atrium, coronary arteries, conduction system and pulmonary artery. Close proximity to the left atrium and aorta may result in fistulous communications with these structures. Rupture into the pericardium resulting in cardiac tamponade is the most dreaded complication, though such an event appears to be very rare. There is a possibility of coexistent aneurysms reinforcing it being a congenital defect. Echocardiography usually establishes the diagnosis. Visualization of the echo-free space with systolic expansion and diastolic collapse of the aneurysmal structure is an important diagnostic feature. However, this phenomenon can be less prominent in a patient with a fistulous communication because the pressure variations within the aneurysm are blunted. Diagnosis is more accurate with a transesophageal echocardiogram than with a transthoracic echocardiogram. Real time 3D echocardiography can also be complimentary to 2D. Computed tomography and MRI both provide excellent multiplanar and 3D images of the aneurysm, its relationship with the coronary arteries, aortic root, and cardiac chambers, which are invaluable to the operating surgeon. The usual recommended treatment is surgery due to potential fatal complications. While there have been some case reports of conservative management and monitoring, there is insufficient data to predict natural course of congenital subvalvular aneurysms. Surgery is technically challenging and associated with high risk of morbidity or mortality The high-risk factors which increase predisposition to rupture include active endocarditis, size of P-MAIVF >3 cm, bicuspid aortic valve, regurgitation, presence of fistula to cardiac chamber or aorta, thrombus in P-MAIVF, compression of adjacent structures(coronary or pulmonary artery). These high risk features would likely contribute to the progression of the pseudoaneurysm and the development of complications. There have been suggestions that patients with thick fibrous and calcific walls might be at lower risk for rupture. Our case is unique in the fact that our patient presented at a young age of 7-yrs as an incidental finding without any prior traumatic or infective insult to the area indicative of a truly congenital weakness of the MAIVF leading to aneurysm formation. She has been closely followed for past 4 years without any significant increase in size of the aneurysm and continues to be asymptomatic. Conclusion: An aneurysm or pseudoaneurysm of the MAIVF in pediatrics age group is a rare disease especially without any preceding infective endocarditis, surgery or congenital heart disease and may be asymptomatic, the region of the MAIVF should be observed carefully by TTE. When necessary, TEE and/or CT scan or MRI should be performed to make a definitive diagnosis. Historically, the usual recommendation has been surgery but there have been case reports of conservative observation in low risk cases.
Ryan Monti has completed his Medical Degree at the age of 29 years from Avalon University Medical School, graduating at the top of his class and named valedictorian of the class of 2013. Dr. Monti is currently an second year Internal Medicine resident at Hackensack UMC Mountainside Hospital. He currently sits on multiple hospital committees, including Critical Care and The high Value Care Committee.
82 year old African American female from Jamaica with past medical history only significant for hypertension, rheumatoid arthritis, colon cancer status post surgery, chemotherapy and radiation 7 years ago with no current evidence of disease, now presenting with shortness of breath for the past 2 -3 days. Patient states that over the previous two to three days she has been having progressively worsening of dyspnea of exertion. Patient ultimately found to have a left ventricular pseudo-aneurysm and underwent successful cardiac surgery for repair. After extensive workup we were unable to determine the cause of this increasing rare pathology.