Cardioscopic spectrum of the left ventricular endocardial surface and its relation to histologic changes in idiopathic myocarditis.

To examine feasibility of percutaneous cardioscopy for diagnosis of idiopathic myocarditis, cardioscopic appearance of the left ventricle and biopsy findings were compared in 21 such patients. The endocardial surface was milky white, red, pink, or reddish brown and edematous at the segments that exhibited histologic changes of acute myocarditis; purplish red in those that exhibited chronic active myocarditis; and yellow in those that exhibited chronic inactive or healed myocarditis. Follow-up study by repeated cardioscopy and biopsy in six patients revealed that the milky white surface disappeared and that the red, pink, and reddish brown surfaces changed to purplish red and then to yellow or white. The results indicate that the endocardial coloration of the left ventricle represents histologic changes and that cardioscopy is feasible for macroscopic pathologic diagnosis and for follow-up of idiopathic myocarditis.