The Journal of Thoracic and Cardiovascular Surgery, Vol 101, 116-120, Copyright © 1991 by The American Association for Thoracic Surgery and The Western Thoracic Surgical Association
Role of dipyridamole-echocardiography test in the evaluation of coronary reserve after coronary artery bypass grafting
A Biagini, S Maffei, M Baroni, M Levantino, M Zanobini, M Piacenti, G Borzoni, S Pugliese, C Comite and L Salvatore
Cardiosurgical Department U.S.L. 12 and University, Pisa, Italy.
The object of this study was to assess the usefulness of the
dipyridamole-echocardiography test in the early evaluation of coronary
artery bypass grafting, when the use of an exercise stress test is
precluded. We studied 39 consecutive patients (37 men and two women, mean
age 57.3 years) referred to our institute for elective coronary artery
bypass. Five patients had single, 12 patients double, 20 patients triple
vessel disease, and two had left main stem disease. Nineteen left internal
mammary artery grafts, 20 sequential grafts, and 39 single vein grafts were
performed. All the patients were subjected to the test before (time range 1
to 3 days) and after (time range 6 to 10 days) the operation in the absence
of therapy. Dipyridamole was administered intravenously 0.56 mg/kg over 4
minutes (low dose); if no effect was apparent, an additional 0.28 mg/kg
over 2 minutes (high dose) was given. During the test, blood pressure and a
twelve-lead electrocardiogram were monitored. An arbitrary wall motion
score was derived by dividing the left ventricle into six regions and
grading from 0 to 3-normokinetic, hypokinetic, akinetic, and dyskinetic
zones. Preoperatively the test was positive in 38 patients as evidenced by
wall motion abnormalities (36 patients had electrocardiographic changes)
and in one patient by electrocardiographic changes and chest pain; 22 tests
were positive after the low dose and 17 after the high dose. Angina was
present in 33 patients. Mean wall motion score was 1.64 per patient in the
basal condition and 4.03 per patient after the test (p less than 0.001).
After coronary bypass in three patients the test was positive at the same
dosage that was used preoperatively, as shown by wall motion abnormalities
(in two patients by electrocardiographic changes, as well). Four patients
had symptoms. Furthermore, at 6 months' follow-up, a treadmill stress test
performed in these three patients was positive for ischemia and angina. The
wall motion score was 1.25 per patient in the basal condition and 1.53 per
patient after the test (no significant difference). When the preoperative
wall motion score obtained after dipyridamole echocardiography was compared
with the postoperative score, a statistically significant difference was
seen: 4.03 per patient versus 1.53 per patient (p less than 001). In eight
patients we observed an improvement of basal myocardial contractility after
the operation, which indicates the reversibility of wall motion
abnormalities observed before coronary bypass. In conclusion our data show
that the dipyridamole-echocardiography test is a suitable method for the
early assessment of bypass grafting when other methods, exercise dependent,
are not indicated.(ABSTRACT TRUNCATED AT 400 WORDS)
