Left coronary angiography in the pre-operative diagnosis of thrombosis of the left atrium or its appendage in rheumatic mitral stenosis.

We studied the utility of pre-operative selective left coronary angiograms for detecting thrombosis in the left atrium or its appendage in 81 patients with rheumatic mitral stenosis, who subsequently underwent open-heart surgery. Thrombus was predicted by the angiographic demonstration of neovascularity seen as a bunch of small vessels arising from the circumflex branch of the left coronary artery coursing superiorly to the region of the left atrial appendage and terminating in a network of smaller vascular channels with a blush of contrast medium coalescing into small 'lakes'. This pooling of contrast medium was considered essential for positive angiographic diagnosis. Based on these criteria, the angiographic diagnosis of thrombus was made in 27 patients. Thrombus was found in 33 patients at surgery. Selective left coronary angiography had a sensitivity of 72.7%, specificity of 92.7% and predictive value of 88.8% for detecting thrombi in the left atrium or its appendage. Coronary angiography should be performed in all the patients with mitral stenosis who are undergoing cardiac catheterization especially if balloon mitral valvoplasty or closed mitral valvotomy are planned.