Case Report

A 16-year-old boy presented with a progressive history of palpitations and dyspnea on exertion over the past year. He did not report any history of trauma, febrile illness, or severe chest pain preceding his symptoms. There were no episodes of syncope or presyncope. Physical examination did not reveal stigmata of Marfan’s syndrome, Ehlers-Danlos syndrome, or any other collagen vascular diseases. His pulse rate was 105 beats/min, and his blood pressure was 110/60 mm Hg. A prominent diastolic thrill was palpable over the precordium. Auscultation revealed a loud holodiastolic murmur over the left third intercostal space of mixed frequency. Electrocardiography showed a prolonged PR interval (240 ms), left anterior hemiblock, and right bundle branch block (trifascicular block) with intermittent ventricular ectopics. No evidence of ischemia or infarction was noted on electrocardiography. Chest x-ray revealed cardiomegaly with mild pulmonary venous hypertension.

On transthoracic echocardiographic examination, the apical 4-chamber view revealed a multicystic echo-free space in the interventricular septum (IVS) that extended from its base up to the left ventricular (LV) apex and all around the lateral wall of the left ventricle up to the base of the papillary muscles ( Figures 1 and 2 , Videos 1 and 2 ). This echo-free space was found to originate from the right coronary sinus (RCS) ( Figures 3 and 4 , Videos 3 and 4 ). The walls of this cystic cavity were partly calcified. Doppler detected to-and-fro flow into the cavity. There was significant diastolic regurgitation into this false cavity. There was no aortic valvular regurgitation ( Figure 3 , Video 3 ). This entire echo-free space was compressing the left ventricle and thereby causing moderate LV dysfunction and global hypokinesia (LV ejection fraction, 40%). Furthermore, transthoracic echocardiography revealed that the left coronary sinus (LCS) was also ruptured, and the rupture was contained by a false aneurysm. This aneurysm dissected into the roof of the left atrium from the aortomitral intervalvular fibrosa. This false aneurysm contained a large layered thrombus. Mobile tissue flaps could be seen, indicating breaks in the wall of both left and right sinuses ( Figure 4 , Video 4 ). The left coronary artery was noted to be stretched by this aneurysm, although it was not encroached by the aneurysm. In addition, there was mild mitral regurgitation, most likely due to deformation of the papillary muscle attachment by the cystic spaces. It is noteworthy that the aortic root was not dilated, and the two ruptured sinuses were also normal sized.

Apical 4-chamber view. Multicystic echo-free space within the left ventricle (LV) with a larger submitral part (asterisk) and a smaller apical-anterior part (caret) with a bulging endocardium-subendocardium (arrows) that confines the false aneurysm. LA , Left atrium.

The submitral (asterisk) and apicoanterior (caret) parts of the dissecting aneurysm are seen connected by a narrow central portion (arrow) . LV , Left ventricle.

Apical 5-chamber view with color comparison. The large aneurysm (asterisk) can be seen to arise from the RCS. Regurgitant flow can be seen noted into the aneurysm cavity burrowing into the IVS with an absence of true aortic regurgitation (arrow) . In addition, mild regurgitation across the mitral valve (MV) is noted. LA , Left atrium; LV , left ventricle; NCS , noncoronary sinus.

Parasternal short-axis view at the level of the aortic valve with color comparison in diastole (A) and systole (B) . (A) Note that the aortic root and sinuses of Valsalva are not dilated. Layered thrombus seen in LCS aneurysm (asterisk) . (B) Mobile tissue flaps can be seen indicating breaks in the wall of both left and right sinuses (arrow) . The neck characteristic of false aneurysms is at the break in the sinus wall (arrowheads) .

These echocardiographic findings were confirmed on contrast magnetic resonance imaging, which showed the presence of severe regurgitation into the false cavity with a regurgitation fraction of 60%.

These findings were essentially confirmed at surgery. There were two aneurysms of sinuses of Valsalva, one arising from the RCS and burrowing into the IVS and the other arising from the LCS. The latter burrowed into the aortomitral curtain, mostly extending externally and posteriorly onto the left atrial roof, and contained laminated clots. The aneurysms were repaired using a transaortic approach by exclusion technique using a Gore-Tex (W. L. Gore & Associates, Inc, Elkton, MD) patch. The aortic valve did not need replacement. The postoperative course was uneventful, but the QRS interval widened further with persistent trifascicular block. Twenty-four-hour Holter monitoring did not reveal any episodes of high-degree atrioventricular block. In view of the persistent features of trifascicular block, a VVI permanent pacemaker was implanted on day 12 after surgery as a backup.

Postoperative transthoracic echocardiography ( Video 5 ) revealed that the cystic spaces within the IVS had substantially reduced in size. No flow was seen within these spaces on color Doppler. There was no aortic regurgitation, and the LV ejection fraction was 50%. The patient was discharged and remained asymptomatic after 8 weeks.

Discussion

Aneurysm of the sinus of Valsalva (ASOV) is a rare congenital anomaly (0.15% of all open-heart surgical procedures ) usually diagnosed following rupture (about 80%). Further, an ASOV that dissects into the IVS is an extremely rare entity. Wu et al reported an incidence of 6 cases in 30,700 patients with dissecting aneurysms of the IVS. Even rarer is the presence of multiple (≥2) aneurysms in the same patient. A search of the English literature revealed only 14 reported cases of multiple aneurysms. Finally, ASOV involving the LCS is itself extremely rare (<5% of ruptured ASOVs). It usually causes myocardial ischemia by means of static or dynamic compression of the left coronary artery or by spontaneous dissection. The presence of a thrombus within the aneurysm could be a source of coronary or systemic embolism. It remained to be confirmed whether silent coronary embolism was a cause of LV dysfunction in our patient, as he did not undergo coronary angiography.

The absence of dilatation of either the aortic root or the sinus of Valsalva was a very unusual feature of our case. Aortic dissection has been reported in young girls with Turner’s syndrome in the absence of either congenital heart disease (which included bicuspid aortic valve, coarctation, aortic dilation) or hypertension. Our patient was male, and we did not perform karyotyping (to rule out male mosaic Turner’s syndrome). Thus, it may be possible for the sinus of Valsalva to rupture even in the absence of dilatation. The presence of mobile tissue flaps enables one to identify breaks in the wall of the aorta and thus differentiate false aneurysm formation and simple aneurysmal dilatation of the sinus of Valsalva.

There were other unusual features in our case as well. Extensive dissection by the RCS aneurysm into the IVS and the LV lateral wall was present. We could find only one case report that matched the extent of dissection similar to this patient. However, that was an incidental finding on postmortem autopsy done in a drug addict who died of a stroke. Second, despite severe distortion of the aortic sinuses, there was no true aortic valvular regurgitation. The entire regurgitation occurred into the false cavity in the IVS and thus provided a unique explanation for the holodiastolic murmur and diastolic thrill. Last, despite the extensive involvement of the IVS, the patient had not developed complete heart block. Choudhary et al reported that surgical repair of an ASOV dissecting into the IVS does not offer a guarantee against future arrhythmias and conduction abnormalities. Thus, we prophylactically inserted a permanent pacemaker in this patient. The presence of this unique combination of findings in our patient made this a very unusual case that was successfully managed.