Ultrasonic Doppler Vibrometry: Measurement of Left Ventricular Wall Vibrations Associated With Coronary Artery Disease

We have developed a new method of detecting coronary artery stenoses that uses Doppler ultrasound to measure minute local vibrations in the cardiac wall associated with post-stenotic flow turbulence. In this paper, we present the results of a preliminary clinical study to evaluate the efficacy of this method for detecting coronary artery disease (CAD) using coronary angiography as the gold standard. The study population consisted of 34 patients clinically-indicated for coronary angiography. Based on the catheterization reports, the patients were divided into three categories: severe (obstructive CAD, typically with >70% diameter reduction), moderate (non-obstructive CAD, typically with <50% diameter reduction or diffuse atherosclerosis), and normal (no angiographic evidence of CAD). A diastolic myocardial vibration index (DMVI) was calculated as the ratio of the normalized periodogram spectral energy in the 100~800-Hz frequency band of the instantaneous wall velocity in early diastole to a baseline value during diastasis. The DMVI was significantly higher in severe CAD patients (21.2plusmn3.2 dB) compared to moderate CAD (17.5plusmn3.5 dB) and normal (11.2plusmn4.8 dB). The differences between each of the categories were statistically significant (p<0.05). Severe CAD patients could be distinguished from normal with a sensitivity of 91.7% and specificity of 83.3%. We believe that this method could potentially be developed into a low-cost and accurate test for diagnosis and screening for coronary artery stenosis