PubMed1998
To study the feasibility and diagnostic accuracy of right coronary artery (RCA) narrowing by right ventricular (RV) pulse-wave Doppler tissue sampling during dobutamine stress echocardiography (DSE), 30 patients (mean age 55 +/- 9.5 years, 26 men) with suspected coronary artery disease underwent DSE (up to 40 microg/kg/min with additional atropine during submaximum heart rate responses). Pulse-wave Doppler tissue sampling of RV free walls close to the tricuspid annulus was performed in the apical 4-chamber view. The maximum velocity during the ejection phase, early, and late diastole was measured. Data from 5 consecutive beats were averaged. The measurements were repeated at rest, at low dose (10 microg/kg/min), and at peak dobutamine stress. The results were evaluated for the prediction of significant proximal or medium RCA narrowing (> or = 50% diameter stenosis, assessed by quantitative coronary angiography within the previous 3 months). A progressive increase of the ejection phase velocity (> 25% between 10 microg/kg/min and peak stress) was predictive of a normal RCA, whereas a blunted increase and/or decrease (< 25% of increase) was predictive of significant RCA narrowing: sensitivity (95% confidence intervals): 82% (68 to 96), specificity: 78% (67 to 93), positive predictive value: 69% (52 to 86), negative predictive value: 88% (75 to 100), accuracy: 79% (65 to 94). Pulse-wave Doppler tissue sampling provided analyzable data in 100%, whereas the visual assessment of gray-scale images was possible only in 90%. Thus, in patients with suspected RCA narrowing, pulse-wave Doppler tissue sampling during DSE was able to diagnose significant RCA narrowing.