The human pericardium in vibroacoustic disease

Introduction: One of the main features of vibroacoustic diseaase (VAD) is t he proliferation of the extra-cellular matrix which induces cardiovascular morphological and dynamic changes, and has,been evaluated through echo-Dopp ler. While all subjects exposed to large pressure amplitude (greater than o r equal to 90 dB SPL) and low frequency (less than or equal to 500 Hz) (LPA LF) for at least 15 yr have thickening of some cardiac structure, most freq uently the pericardium, no significant diastolic changes accompany these ob servations. Echocardiography has become the diagnostic method of choice for the VAD. However, there have been no studies relating the echo-images of p ericardial thickening to gross anatomy. Methods: We present the histology a nd ultrastructure of the pericardia of four patients who underwent cardiac surgery. Results: The most important findings concern the real thickening o f the pericardium (values: 1.11, 1.35, 2.19, and 2.33 mm vs, norm: less tha n or equal to 0.5 mm), the dynamic arrangements of mesothelial cells in the serosa layer, and the plasticity of the cells found among the multifascicu lar waveform collagen fibers. We found that the fibrosa of VAD patients has three layers: sandwiched between two thickened layers of normal fibrosa th ere is a loose tissue layer with vascular, nervous, and adipose structures. Conclusion: These features may partially explain why no important diastoli c changes are observed in VAD patients in spite of the pericardium thickeni ng.