Introduction
The efficacy of modern therapeutic methods has made it imperative that an exact diagnosis be established in any given disease state. Both open and closed biopsy techniques haveproved to be of value in providing a histological diagnosis in abnormalities of the liver, kidneys, pleura, and lymph nodes. These procedures enjoy wide clinical usefulness.Recent studies in furthering the clinical and laboratory diagnosis of congenital and valvular cardiac disease have been made. Increseing sophistication in cardiac surgery has not only given impetus to more accurate diagnosis, but has made anesthesia and surgery increasingly safe for patiens with cardiac disease.Despite these advances there remain cardiac disease states of obscure etiology including those of viral or metabolic origin which are difficult to diagnose. Treatable disease may be overlooked unless an exact diagnosis is obtained.Recognizing the need for better delineation of these entities, in 1956, Sutton et al described a technique