NONINVASIVE ASSESSMENT OF LEFT INTERNAL MAMMARY ARTERY GRAFT PATENCY USING TRANSTHORACIC ECHOCARDIOGRAPHY

Citation
Jj. Crowley et Lm. Shapiro, NONINVASIVE ASSESSMENT OF LEFT INTERNAL MAMMARY ARTERY GRAFT PATENCY USING TRANSTHORACIC ECHOCARDIOGRAPHY, Circulation, 92(9), 1995, pp. 25-30
Citations number
19
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Cardiac & Cardiovascular System",Hematology
Journal title
ISSN journal
0009-7322
Volume
92
Issue
9
Year of publication
1995
Supplement
S
Pages
25 - 30
Database
ISI
SICI code
0009-7322(1995)92:9<25:NAOLIM>2.0.ZU;2-5
Abstract
Background Cardiac catheterization is the only practical method of ass essing internal mammary artery graft patency. A noninvasive method wou ld be useful in patients with recurrence of anginal symptoms after cor onary artery bypass graft surgery. We hypothesized that transthoracic echocardiography could provide information on blood velocity and anato my and therefore has the potential to allow measurement of blood flow. Methods and Results High-frequency (5 MHz) transthoracic echocardiogr aphy was performed on 41 consecutive patients (mean age, 67+/-6 years) who had had left internal mammary artery grafts to the left anterior descending coronary artery (LAD) and were undergoing coronary angiogra phy because of recurrence of anginal symptoms. The results were compar ed with those from 19 patients (mean age, 58+/-11 years) in whom an un grafted left internal mammary artery was assessed and with those from 15 patients (mean age, 61+/-12 years) who had angiographically normal coronary arteries in whom the LAD was studied. Doppler velocity profil es of the left internal mammary graft were obtained in 35 of the 41 st udy patients (81%). In all cases, a biphasic pattern of blood flow was recorded that corresponded to systole and diastole. Two different flo w patterns were observed. In 25 patients with a normal graft or modera te (<70%) stenosis (group A), blood flow velocity was maximal during d iastole. This pattern was also seen in the LAD control group. In 10 pa tients with severe (>70%) graft stenosis (group B), blood velocity was maximal during systole, and low velocities were recorded during diast ole. This pattern was also seen in the ungrafted internal mammary arte ry control group. The diastolic fraction of the velocity lime integral s for group A was 0.77+/-0.07, and for group B was 0.27+/-0.01 (P<.05) . A diastolic velocity time integral fraction <0.5 predicted severe st enosis with a sensitivity and specificity of 100%. The ratio of systol ic-to-diastolic peak velocities for group A was 0.54+/-0.26 and for gr oup B was 3.45+/-0.74 (P<.05). A systolic-to-diastolic peak velocity r atio >1 predicted severe stenosis with a sensitivity of 100% and speci ficity of 85%. Mean graft blood flow was 63+/-21 mL/min. There was no significant difference in mean blood flow between any of the patient g roups studied. Conclusions High-frequency transthoracic echocardiograp hy allows identification of the left internal mammary grafts and measu rement of blood flow. Compared with patent grafts or those with modera te lesions, severe stenoses demonstrated different Doppler velocity pa tterns. Use of this technique may allow noninvasive detection of signi ficant stenoses of the left internal mammary artery graft.