Echocardiography in Vibroacoustic Disease

Introduction. In 1980, research into the effects of low frequency noise (LFN, <500 Hz, including infrasound) -induced pathology began to be studied among a group of aircraft technicians. Vibroacoustic disease (VAD) has since been defined as the whole-body pathology caused by excessive exposure to LFN. In 1987, the first autopsy of a VAD patient was performed. Among the plethora of findings that laid the foundation of many concurrent avenues of research, was the enormous thickening of the pericardium (a thin sac, <0.5mm thickness, that surrounds the heart). Based on this finding, an echocardiography program was set up among an initial group of 10 technicians. This report exposes the chronological findings of echocardiography in VAD patients. Methods. The results of echocardiograms performed among aircraft technicians, commercial airline pilots and flight attendants, and populations exposed to environmental LFN are gathered and collectively discussed. Results. Echocardiograms of VAD patients disclose pericardial thickening that may appear concurrently with valve thickening, but with no consequences for diastolic mechanics. The degree of severity of VAD is related to the amount of thickening seen through echocardiography, which, in turn, is related to the cumulative amount of LFN-exposure the individual has had. Discussion. Echocardiography is the diagnostic tool of choice for VAD. The pericardial thickening seen through echo-imaging has been confirmed with histological and electron microscopy imaging and is the object of an independent study. Pericardial thickening due to excessive LFN exposure is not exclusive to LFN-exposed workers but is seen even in children who live in LFN environments. Children with in utero exposure to LFN noise have been the most severe cases. Despite the validity of pericardial echo-imaging for VAD diagnosis, a common protocol among mainstream science has yet to established.