Doppler monitoring of the vascular resistance in the lower limbs during dipyridamole test in preparation for myocardial tomoscintigraphy.
OBJECTIVE
the aim of this work was to quantify the intensity of the vasodilation induced by dipyridamole used to simulate a stress test during a myocardial tomoscintigraphy.


METHODS
Doppler measurements of the femoral artery and the thoracic aorta were made on 26 patients (11 men, 15 women), using transducers attached to the skin, measurements being performed every 2 min during the 10 min of the stress test. The following parameters were measured: (a) the vascular resistance index of the lower limbs defined as R(fa)=D/S with S and D, respectively, the maximum amplitude of the systolic wave and the maximum amplitude of the diastolic reflux measured on the Doppler femoral spectrogram; (b) the aortic and femoral blood flows obtained from the mean velocity on the Doppler spectrogram.


RESULTS
14 of the 26 patients (54%) showed a significant vasodilation (i.e. a decrease of R(fa) of more than 10%). Eighty-seven percent of the patients with a positive myocardial scintigraphy showed a vasodilation. Sixty-six percent of patients who had prior vasodilator treatment showed no vasodilation. A slight decrease in blood pressure was observed for vasodilated patients but also for non-vasodilated patients. The aortic flow increased slightly for all patients.


CONCLUSIONS
Doppler monitoring of femoral vascular resistance is a useful method for quantifying the dipyridamole-induced vasodilation, and hence the stress level upon which the diagnostic efficiency of myocardial scintigraphy is depending. Our study demonstrates that testing with dipyridamole was inconclusive in 66% of patients who had already vasodilator treatment.
Eder
V
V
Service de Medecine Nucléaire et Ultrasons, CHU Trousseau, 37044, Tours, France. eder@med.univ-tours.fr
Hérault
S
S
Boulay
J l
Jl
Porcher
M
M
Tondereau
G
G
Pottier
J M
JM
Arbeille
P
P
D001013:Aorta, Thoracic / Q000000981:diagnostic imaging; D001783:Blood Flow Velocity / Q000187:drug effects; D004176:Dipyridamole; D005260:Female; D005263:Femoral Artery / Q000000981:diagnostic imaging; D006321:Heart / Q000000981:diagnostic imaging*; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007866:Leg / Q000098:blood supply*; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D018608:Ultrasonography, Doppler; D014655:Vascular Resistance / Q000187:drug effects*; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents
D014665:Vasodilator Agents; D004176:Dipyridamole