Discussion
Sinus of Valsalva (SOA) aneurysms defined as a significant dilatation or enlargement of the aortic root area, which located between the aortic valve annulus and the sinotubular junction [1]. The incidences of the right coronary sinus, noncoronary sinus and left coronary sinus aneurysms are approximately 70-90%,10-20% and <5%, respectively. It is a rare aortic root anomaly, associated with congenital defects in the aortic media, and rarely due to acquired conditions [2]. Rupture of SOV is a rare complication, the consequence of which depends on its location. Rupture can occur into four cardiac chambers, but rarely into the interventricular septum (IVS) [3]. In our case, the patient had bicuspid aortic valve and two coronary sinus, ruptured anterior SOV aneurysm formed paravalvular aortic root pseudoaneurysm, which was communicated with IVS dissecting aneurysm.
Aortic root pseudoaneurysm is usually occurring secondary to trauma, infection, prosthetic valve endocarditis, etc. The main complications of pseudoaneurysms are compression of the surrounding tissue, thrombus formation in the aneurysm cavity, and cardiogenic embolism. In this case, the large pseudoaneurysm invade the IVS dissecting aneurysm extending from the basal anteroseptum to anterior wall of the left ventricle, which the IVS muscle tore two layers to form cystic cavity.
In the literature report, IVS dissecting aneurysm is a rare complication, which caused by ruptured aneurysm of the SOV, congenital coronary artery fistulas, infective endocarditis, or myocardial infarction [4]. We present a rare case of IVS dissecting aneurysm that resulted from a paravalvular aortic root pseudoaneurysm, which may cause significant hemodynamic and anatomical derangements. It has a progressive course and a poor prognosis, and may cause arrhythmias, conduction abnormalities, or congestive heart failure [5]. The complaint of this patient was chest pain and had heart failure initially, one possible explanation is that disrupted aortic root anatomy and massive IVS dissecting aneurysm compresses the coronary arteries leading to myocardial ischemia [6][7].