Left ventricular outflow tract to left atrial communication secondary to rupture of mitral-aortic intervalvular fibrosa in infective endocarditis: Diagnosis by transesophageal echocardiography and color flow imaging

Abstract

Infection of the mitral-aortic intervalvular fibrosa occurs most commonly in association with infective endocarditis of the aortic valve. Infection of the aortic valve results in a regurgitant jet that presumably strikes this subaortic interannular zone of fibrous tissue and produces a secondary site of infection. Infection of this interannular zone then leads to the formation of subaortic abscess or pseudoaneurysm of the left ventricular outflow tract. This infected zone of mitral-aortic intervalvular fibrosa or subaortic aneurysm can subsequently rupture into the left atrium with systolic ejection of blood from the left ventricular outflow tract to the left atrium. This report describes the echocardiographic findings in three patients with pathologically proved left ventricular outflow tract to left atrial communication. Precise preoperative diagnosis is important, and this lesion should be differentiated from ruptured aneurysm of the sinus of Valsalva and perforation of the anterior mitral leaflet. Transthoracic echocardiography using color flow imaging and conventional Doppler techniques may show an eccentric mitral regurgitation type of signal in the left atrium originating from the region of the left ventricular outflow tract. However, transesophageal echocardiography provides an accurate preoperative diagnosis and should be used intraoperatively during repair of such lesions.

Aneurysm of the mitral-aortic intervalvular fibrosa as a rare cause of angina pectoris: Angiographic demonstration

“…Those pseudoaneurysms larger than 4 cm and extending posteriorly, under the left main and circumflex coronary arteries, have been previously and presently described to compress the adjacent coronary arteries [10,12]. Other complications related to the expansion of an aneurysm or pseudoaneurysm of the MAIF are cardiac tamponade due to rupture into the pericardial sack [3,5], rupture into the left atrium causing mitral regurgitation [7], and embolic episodes due to thrombus formation within aneurysmatic cavity [12], although sometimes aneurysm of the MAIF can be asymptomatic for a long period [11].…”

Pseudoaneurysm of Mitral-Aortic Intervalvular Fibrosa

“…Smaller pseudoaneurysms may be more difficult to distinguish from an abscess, but the systolic expansion and diastolic collapse of the area should alert the echocardiographer to this condition and help in differentiating between these two important clinical entities. 5,8 MAIVF is a relatively avascular structure and, as such, it offers little resistance to infection. A general necropsy image (not from our patient) is shown in figure 2, and shows the anatomical details of the areas around the MAIVF.…”

“…A TTE should be done initially, but if there is any doubt regarding the thickening at the posterior aortic root or at the base of the anterior mitral leaflet, TEE should be utilized to further evaluate this area as it has a much higher sensitivity and specificity in diagnosing such complications. 8,9 In summary, pseudoaneurysm of the MAIVF is a relatively rare complication of infective endocarditis. It should be kept in mind in patients who are suspected of an abscess in the region of the sinus of Valsalva.…”

An unusual complication after aortic valve replacement

“…Rupture of PA into the left atrium should be differentiated from perforation of the anterior mitral leaflet and ruptured sinus of valsalva aneurysm. 5 The PA may rupture into the left atrium or aorta. 1,5 The pulsatility of the PA becomes less pronounced after rupture.…”