Response Response

To the Editor,

We fully acknowledge the value of Salazar et al's recent publication concerning a patient with a membranous interventricular septal aneurysm (MIVSA) who experienced a cerebral embolism and in whom thrombus was detected by transesophageal echocardiography.¹ Unfortunately, their work had not been published when we preparing our case report for submission to the Images in Cardiology section of the Revista Española de Cardiología.² Therefore, we were not able to refer to it. The other case that described transesophageal echocardiographic diagnosis of a thrombotic aneurysm³ concerned aneurysm of the atrioventricular septum, which is a rare phenomenon that affects the septum separating the right atrium from the left ventricle. This case did not appear when we carried out a MEDLINE search for MIVSA and thrombus. Nevertheless, we acknowledge our error and regard that publication as being the first report of a thrombotic MIVSA being detected by transesophageal echocardiography.

On the other hand, our publication² was not an article specifically concerned with establishing thrombotic MIVSAs as a source of emboli, as suggested in the letter to the editor. It was, instead, simply an opportunity to present an echocardiographic observation that was specific to a patient with situs inversus and corrected congenital transposition. Consequently, the phrase "it has been speculated that membranous septum aneurysms may be an intracardiac source of emboli" referred only to the limited evidence available in the literature for such an association despite the high prevalence of MIVSAs in patients with congenital heart disease. In fact, as Salazar et al's work¹ demonstrates, the presence of thrombus was confirmed in only 3 out of 6 published cases of patients with thromboembolism who were treated surgically. Nonetheless, we agree that either observation of a structure resembling thrombus within a MIVSA or, when no thrombus is observed on echocardiographic images, the coexistence of cryptogenic cerebrovascular accident and a MIVSA can justify anticoagulant treatment, or even surgical intervention in patients with a low risk of surgical complications.