Noninvasive assessment of left and right internal mammary artery graft patency with high-frequency transthoracic echocardiography.
OBJECTIVE
The aim of this study was (1) to visualize internal mammary artery grafts (IMAG) on coronary artery by transthoracic echocardiography and (2) to assess the patency of the grafts.


METHODS
Twenty-three patients (21 men, 56 +/- 6 years) with previous coronary artery bypass grafting were studied at baseline and after they underwent low-dose dipyridamole infusion. The parameters obtained were systolic (SPV) and diastolic (DPV) peak velocities and their ratio (DPV/SPV); the dipyridamole infusion to baseline ratio of DPV was an index of IMAG blood flow reserve (FR). Two groups of patients were selected at baseline: group A, (n = 12) with a DPV/SPV >1, and group B (n = 11), with a DPV/SPV <1.


RESULTS
The IMAG was identified in all patients. Intraluminal flow signals obtained with pulsed wave Doppler showed a biphasic pattern (1 systolic and 1 diastolic wave). After dipyridamole infusion was administered, flow velocities increased in 11 of 12 patients in group A and in 5 of 11 patients in group B. In group A the DPV/SPV increased from 1.79 +/- 0.47 to 1.8 +/- 0.43 (P = not significant), and the FR was 1.8 +/- 0.4. In group B the DPV/SPV increased from 0. 46 +/- 0.05 to 0.5 +/- 0.09 (P = not significant), and the FR was 1. 3 +/- 0.41. Coronary angiography showed the graft patency in all patients in group A and in 5 patients in group B with increased flow velocity after dipyridamole infusion. In the identification of graft stenosis at baseline, DPV/SPV showed 100% sensibility and 58% specificity, and FR showed 92% sensibility and 84% specificity.


CONCLUSIONS
Doppler echocardiographic evaluation of the IMAG is a simple noninvasive method to assess the functional impairment of the vessel.
De Simone
L
L
Department of Cardiology, Laboratory of Echocardiography, Azienda Ospedaliera Monaldi, Napoli, Italy. ludes@iol.it
Caso
P
P
Severino
S
S
Scherillo
M
M
D'Andrea
A
A
Varricchio
A
A
Violini
R
R
Mininni
N
N
D000787:Angina Pectoris / Q000601:surgery; D001783:Blood Flow Velocity; D003251:Constriction, Pathologic; D017023:Coronary Angiography; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000503:physiopathology; D004176:Dipyridamole / Q000008:administration & dosage; D018618:Echocardiography, Doppler, Color; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D007387:Internal Mammary-Coronary Artery Anastomosis; D008297:Male; D008875:Middle Aged; D012039:Regional Blood Flow; D012680:Sensitivity and Specificity; D014654:Vascular Patency; D014665:Vasodilator Agents / Q000008:administration & dosage
D014665:Vasodilator Agents; D004176:Dipyridamole