UNROOFED CORONARY SINUS SYNDROME: DIAGNOSTIC CONSIDERATION BY CONTRAST ECHOCARDIOGRAPHY AND USEFULNESS OF TRANSESOPHAGEAL ECHOCARDIOGRAPHY AND MAGNETIC RESONANCE IMAGING

Kanji Iga MD, Kenjiro Hori MD, Tadashi Matsumura MD, Hiromitu Gen MD, Muneto Yamashita* MT and Shuichi Takahashi* MT

We present two cases with unroofed coronary sinus syndrome without a left superior vena cava (1); one associated with mitral stenosis and the other an isolated form. The diagnostic clue was a markedly enlarged coronary sinus with color flow in it detected by trans-thoracic echocardiography. Contrast echocardiography with injection of contrast medium through the left antecubital vein (2) showed negative jet from the coronary sinus in the right atrium meaning a left-to-right shunt through the enlarged coronary sinus. This enlarged coronary sinus was clearly seen lying behind the left atrium by trans-esophageal echocardiography and a communication between the left atrium and the coronary sinus was documented. Echo Doppler gave us additional information about the presence of flow across the fenestrations. Spin echo magnetic resonance imaging demonstrated the fenestration present between the coronary sinus and the left atrium, and cine mode confirmed the flow across these fenestrations.

When the coronary sinus is enlarged on trans-thoracic echocardiography and cannot be filled by contrast echocardiography via the left antecubital vein, further examination on suspicion of the presence of an unroofed coronary sinus is necessary. Trans-esophageal echocardiography and magnetic resonance imaging give us useful information in this situation.