title: The human pericardium in vibroacoustic disease.
abstract: BACKGROUND
  One of the main features of vibroacoustic disease (VAD) is the proliferation of the extra-cellular matrix which induces cardiovascular morphological and dynamic changes, and has been evaluated through echo-Doppler. While all subjects exposed to large pressure amplitude (> or =90 dB SPL) and low frequency (< or =500 Hz) (LPALF) for at least 15 yr have thickening of some cardiac structure, most frequently the pericardium, no significant diastolic changes accompany these observations. Echocardiography has become the diagnostic method of choice for the VAD. However, there have been no studies relating the echo-images of pericardial thickening to gross anatomy.
  
  
  METHODS
  We present the histology and ultrastructure of the pericardia of four patients who underwent cardiac surgery.
  
  
  RESULTS
  The most important findings concern the real thickening of the pericardium (values: 1.11, 1.35, 2.19, and 2.33 mm vs. norm: < or = 0.5 mm), the dynamic arrangements of mesothelial cells in the serosa layer, and the plasticity of the cells found among the multifascicular waveform collagen fibers. We found that the fibrosa of VAD patients has three layers: sandwiched between two thickened layers of normal fibrosa there is a loose tissue layer with vascular, nervous, and adipose structures.
  
  
  CONCLUSIONS
  These features may partially explain why no important diastolic changes are observed in VAD patients in spite of the pericardium thickening.
authors: Occupational Medicine Research Center, Lisbon, Portugal.
authors: N A
authors: NA
authors: Castelo Branco
authors: A P
authors: AP
authors: Aguas
authors: A
authors: A
authors: Sousa Pereira
authors: E
authors: E
authors: Monteiro
authors: J I
authors: JI
authors: Fragata
authors: F
authors: F
authors: Tavares
authors: N R
authors: NR
authors: Grande
mesh_terms: D000328:Adult; D015150:Echocardiography, Doppler; D005355:Fibrosis; D006331:Heart Diseases / Q000000981:diagnostic imaging / Q000209:etiology* / Q000473:pathology* / Q000601:surgery; D006801:Humans; D008297:Male; D008855:Microscopy, Electron, Scanning; D009623:Noise, Occupational / Q000009:adverse effects*; D009784:Occupational Diseases / Q000000981:diagnostic imaging / Q000209:etiology* / Q000473:pathology* / Q000601:surgery; D010496:Pericardium / Q000473:pathology* / Q000648:ultrastructure*; D013997:Time Factors; D014732:Vibration / Q000009:adverse effects*