Quest for the Vulnerable Atheroma: Carotid Stenosis and Diametric Strain--A Feasibility Study.

The Bernoulli effect may result in eruption of a vulnerable carotid atheroma, causing a stroke. We measured electrocardiography (ECG)-registered QRS intra-stenotic blood velocity and atheroma strain dynamics in carotid artery walls using ultrasonic tissue Doppler methods, providing displacement and time resolutions of 0.1 µm and 3.7 ms. Of 22 arteries, 1 had a peak systolic velocity (PSV) >280 cm/s, 4 had PSVs between 165 and 280 cm/s and 17 had PSVs <165 cm/s. Eight arteries with PSVs <65 cm/s and 4 of 9 with PSVs between 65 and 165 cm/s had normal systolic diametric expansion (0% and 7%) and corresponding systolic wall thinning. The remaining 10 arteries had abnormal systolic strain dynamics, 2 with diametric reduction (>-0.05 mm), 2 with extreme wall expansion (>0.1 mm), 2 with extreme wall thinning (>-0.1 mm) and 4 with combinations. Decreases in systolic diameter and/or extreme systolic arterial wall thickening may indicate imminent atheroma rupture.

Transthoracic coronary Doppler vibrometry in the evaluation of normal volunteers and patients with coronary artery stenosis.

Coronary artery vibrometry is a new transthoracic Doppler ultrasound method for the detection of coronary artery stenosis. It detects audio-frequency vibrations generated by coronary artery luminal diameter reduction. We studied 31 patients with known or suspected stenosis using coronary artery vibrometry and quantitative coronary angiography and 83 normal volunteers. A tissue vibration difference index (TVDI) was calculated from the left anterior descending, circumflex, left main and right coronary arteries. Accuracy for coronary artery stenosis detection using TVDI was assessed. Sensitivity for detecting coronary stenosis equal or greater than 25% diameter reduction was 89% in the left anterior descending coronary artery (16/18, 95% confidence interval [CI] = 64%-98%), 87% in the right coronary artery (13/15, 95% CI = 58%-98%), 83% in the circumflex coronary artery (5/6, 95% CI = 36%-99%) and 100% in the left main artery (3/3, 95% CI = 31%-100%). The median TVDI increased with severity of stenosis, suggesting that this measure might be used to track progression/regression of coronary artery stenosis.

Development of an interactive Coronary Doppler Vibrometry system for detection of coronary artery disease.

Coronary artery disease is a deadly and costly condition and represents an important public health issue globally. Coronary Doppler vibrometry (CDV), a new noninvasive coronary artery stenosis detection technique, showed encouraging results in our recent clinical study. However, the CDV system required lengthy offline data analysis, thus it did not provide any feedback during examination on the quality of data, not to mention analysis results. To overcome these limitations, we have developed a new CDV system that interactively performs acquisition, analysis and display of a complete data set while a subject is still on the examination table. Our system is based on a commercial ultrasound machine, and it will be a useful tool for CDV research and clinical studies in the future.

Blunt chest trauma victims: role of intravascular ultrasound and transesophageal echocardiography in cases of abnormal thoracic aortogram.

PURPOSE: The objective of our study was to use transesophageal echocardiography (TEE) and intravascular ultrasonography (IVUS) to evaluate their role in interrogating abnormal or equivocal findings seen on thoracic aortography performed on blunt chest trauma patients. METHODS: A prospective, nonblinded, observational, institutional review board-approved study of IVUS and TEE was conducted in acute blunt chest trauma victims with abnormal findings on thoracic aortograms. IVUS was performed with a 20-MHz catheter and TEE was performed with an omniplane probe. RESULTS: Abnormal aortographic findings were present in 10 men and 4 women (mean age, 40.5 years). All 14 patients were evaluated with IVUS and 13 with TEE. TEE was not performed on one patient because of time constraints. By IVUS, there were 11 true-positives, 2 true-negatives, and 1 equivocal (considered as false-negative), resulting in 91.7% sensitivity and 100% specificity. In the equivocal case, an intimal flap was missed by IVUS and by TEE, but was present at surgery. By TEE, there were six true-positives, two true-negatives, one false-positive, and four false-negatives, resulting in 60% sensitivity and 66.7% specificity. In the false-positive case, an avulsed intercostal artery without an intimal flap was found at surgery. The remaining three false-negative cases were a missed intimal flap, a missed intramural hematoma, and a missed intimal flap obscured by a mural hematoma. In our study, both IVUS and TEE were found to be diagnostic in the four equivocal aortograms. Three of the equivocal results were cases read as a prominent ductus diverticulum versus a pseudoaneurysm. Two were confirmed to be false lumen/pseudoaneurysm by both IVUS and TEE, whereas the other was confirmed to be a prominent ductus diverticulum by both of these modalities. In the fourth equivocal case, thoracic aortography showed an abnormal contour but no intimal flap located along the lesser curvature of the aorta at the junction of the arch and isthmus. No abnormalities were found by IVUS or TEE. This patient was followed clinically. A follow-up thoracic aortogram obtained 1 year later showed no aortic injury. CONCLUSION: When thoracic aortography yields an abnormal and especially equivocal findings, both IVUS and TEE are helpful in further sorting this out rather than subjecting the patient to a potentially unnecessary thoracotomy. In cases of aortic injury suspected at the lesser curvature of the arch-isthmic junction, TEE allowed better delineation because of multiplane imaging capability.