Background. In-stent restenosis is still a significant problem, and early diagnosis of in-stent restenosis after coronary intervention is an important issue. We sought to clarify whether 1) Doppler echocardiography is feasible to visualize instent flow signal, and 2) in-stent coronary restenosis can be detected by transthoracic Doppler echocardiography (TTDE).
Methods. 1) A Doppler flow phantom with stent-implanted tubing was used. Under color Doppler flow mapping, we measured in-stent flow velocities by pulsed Doppler echocardiography and Doppler guidewire. 2) TTDE was performed in 128 patients after stent implantation in the left anterior descending artery (LAD) (18 with in-stent restenosis, group R; 110 without restenosis, group N). After searching for localized aliasing with color Doppler echocardiography, coronary flow velocities were measured at the alias (stenotic) site and at the pre-stenotic site.
Results. 1) In-stent flow was visualized by color Doppler echocardiography, and mean velocities that were measured by pulsed Doppler echocardiography and Doppler guidewire showed good agreements (y=0.86×+6.8, r=0.99). 2) The LAD was visualized in 118 patients. Localized aliasing was detected in 16 patients in group R and 38 patients in group N. The pre-stenotic to stenotic MDV ratio was significantly lower in group R than group N (0.43±0.07 vs. 0.67±0.13, p<0.001). Localized aliasing with the pre-stenotic to stenotic mean diastolic velocity ratio < 0.5 had a sensitivity of 94% and a specificity of 89% for the detection of in-stent restenosis.
Conclusions. Doppler echocardiography could detect coronary flow signal directly through the coronary stent in vitro. TTDE is feasible for noninvasive detection of in-stent coronary restenosis in patient after coronary stent implantation.

View full abstract

Background. Color M-mode Doppler echocardiography provides accurate evaluation of LV diastolic function noninvasively and is reportedly preload independent compared with pulsed Doppler transmitral velocity indexes. This study aimed to determine the prognostic significance of left ventricular (LV) diastolic function in patients with different degrees of chronic LV systolic dysfunction using color M-mode Doppler echocardiography.
Methods. A total of 98 consecutive subjects (mean age 57 years, 78 males) with LV systolic dysfunction (61 with previous myocardial infarction and 37 with dilated cardiomyopathy) underwent clinical and echocardiographic evaluation to determine functional status. Measurements of LV and left atrial dimensions, LV ejection fraction (EF), the peak of early and late diastolic transmitral velocities (E and A, respectively), the E/A ratio, deceleration time of E velocity and isovolumic relaxation time using conventional echo-Doppler techniques, and LV flow propagation velocity (FPV) and FPV/E using color M-mode Doppler echocardiography were taken.
Results. During the mean follow-up period of 37±28 months, 26 patients had cardiovascular events (death in 4, congestive heart failure in 13, ventricular tachycardia in 6, and cerebral infarction in 3). EF was the single independent predictor of cardiovascular events. While, in the subgroup with EF <0.35, the functional class was the single significant predictor of cardiovascular events, FPV/E was the single best predictor of cardiovascular events in the subgroup with EF ≥0.35.
Conclusions. The evaluation of LV diastolic function using color M-mode Doppler-derived FPV/E contributes to predicting clinical outcomes of patients with mildly depressed LV systolic function.

View full abstract

Aortic dissection presenting as a prolonged febrile syndrome is an uncommon condition and the diagnosis is often delayed in such cases. We report a case of a patient with febrile temperature and early diagnosis as aortic dissection by transthoracic echocardiography.

View full abstract

A cystic lesion between the left internal thoracic artery (LITA) graft and left anterior descending artery (LAD) flow was detected by routine transthoracic echocardiography in a patient after coronary artery bypass grafting. The cystic lesion communicated with the anastomotic site of the LITA graft to LAD, and it was diagnosed as a pseudoaneurysm of the LITA graft by transthoracic echocardiography.
Because pseudoaneurysm of a coronary bypass graft is a potentially fatal complication after coronary artery bypass grafting, it is important to detect the LITA graft flow at the anastomotic site by transthoracic echocardiography in routine examination.

View full abstract