Multiple coronary fistula formation associated with a huge left atrial thrombus in rheumatic mitral valve stenosis

Acquired fistulous communication with the left atrial (LA) chamber has been described in the presence of LA mural thrombus in patients with rheumatic mitral stenosis (MS). Hereby, we present the case of a 74-year-old man with rheumatic MS and a huge LA thrombus found in echocardiography. Coronary angiography revealed an extensive fistula formation feeding mainly from the atrial branches of left circumflex and right coronary arteries and draining into the LA chamber. Moreover, left anterior descending (LAD) and right coronary arteries had slow flow with regional wall motion abnormality in the LAD territory and left ventricular ejection fraction of 35% in echocardiography. <Learning objective: This is a unique case of neovascular formation in terms of number and extent of the fistulous connections. It appears that angiographic evidence of neovascularity and fistula formation in patients with rheumatic mitral stenosis is a highly specific sign for the presence of left atrial thrombus.>.