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[Pathology of the papillary muscles]
Abstract:
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.
Insights
Papillary muscle (PM) damage, particularly in the mitral valve, can result from myocardial infarction or endocarditis, leading to heart failure. Autopsy findings reveal PM necrosis, fibrosis, and rupture as common pathologies.
Area of Science:
- Cardiovascular Pathology
- Autopsy Studies
- Cardiac Anatomy
Context:
- Papillary muscle (PM) damage is a significant, yet often under-recognized, complication in cardiovascular disease.
- Understanding the pathological spectrum and clinical sequelae of PM damage is crucial for patient management.
Purpose:
- To review anatomoclinical findings in papillary muscle damage from a large autopsy series.
- To correlate pathological findings with clinical manifestations and diagnostic limitations.
Summary:
- Autopsy review of 21 cases of papillary muscle damage revealed mitral PM involvement in 17 cases, with posteromedial PM affected in 11 (8 with necrosis, 3 with fibrosis, 2 with rupture).
- Mitral anterolateral PM damage occurred in 4 cases (myocardial infarction, fibrosis, hemorrhage, infectious endocarditis). Tricuspid PM involvement was noted in 4 cases (myocardial infarction, fibrosis).
- Microscopic examination of myocardial infarction cases showed PM necrosis, interstitial fibrosis, and in one case, previously undescribed damage to a central longitudinal artery.
Impact:
- Mitral PM infarction can precipitate regurgitant murmurs, heart failure, and fatal arrhythmias, despite a lack of left atrial enlargement on imaging.
- Electrocardiogram (ECG) findings were not diagnostically useful for PM damage.
- This study provides insights for refining diagnostic and surgical strategies for papillary muscle dysfunction.