[Pathology of the papillary muscles]

Anatomoclinical findings in 21 cases of papillary muscle (PM) damage found in 4,000 consecutive autopsies are reviewed. Mitral PM muscles were involved in 17 cases, the posteromedial muscle in 11 patients, in 8 of these with necrosis (N) in 3 with fibrosis (F), in 2 with rupture. The mitral antero-lateral (MAL) was involved in 4 cases, by myocardial infarction (MI), fibrosis, hemorrhage and infectious endocarditis (IE). Both mitral PM were involved in two patients (MI and endomyocardial fibrosis). Tricuspid PM involvement was found in 4 cases. In two because of MI and the two remaining with fibrosis. In the 12 cases with MI microscopic examination showed, PM necrosis of variable magnitude: in the 7 cases with F, there was increased interstitial tissue by connective tissue; in the case with IE there was severe inflammatory reaction with microabscess formation and in one case, a small central longitudinal artery was damaged, a finding not previously described. Mitral PM infarction caused regurgitant murmurs, increase in heart size, heart failure and death from acute pulmonary edema or serious arrhythmias. There was no radiological evidence of left atrial enlargement. ECG findings were not useful in the diagnosis. Based on this anatomoclinical experience considerations are made about other diagnostic and surgical methods.