Inhibition of dipyridamole-induced ischemia by antianginal therapy in humans. Correlation with exercise electrocardiography.
BACKGROUND
Dipyridamole echocardiography test (DET: two-dimensional echocardiographic monitoring with dipyridamole infusion up to 0.84 mg/kg in 10 minutes) is a useful tool for the noninvasive diagnosis of coronary artery disease. Aims of the present study were to assess the effects of antianginal drugs on dipyridamole-induced ischemia and to evaluate whether drug-induced changes in DET response may predict variations in exercise tolerance.


RESULTS
Fifty-seven patients with angiographically assessed significant coronary artery disease (greater than 70% lumen reduction in at least one major coronary vessel) performed a DET and an exercise electrocardiography test (EET) in random order both off treatment and on antianginal drugs (beta-blockers, calcium antagonists and nitrates, alone or in various combinations). The criterion for DET positivity was a transient dyssynergy of contraction absent or of a lesser degree in the baseline examination. In DET, two parameters were evaluated: the dipyridamole time (i.e., the time from onset of dipyridamole infusion to obvious dyssynergy) and the wall motion score index. DET sensitivity was 91% off therapy and fell to 65% under therapy (p less than 0.01). In the 37 patients who had a positive DET both off and on therapy, the dipyridamole time increased from 6 +/- 3 (off therapy) to 8 +/- 3 minutes (on therapy) (p less than 0.01). The wall motion score index at peak dipyridamole went from 1.38 +/- 0.14 to 1.31 +/- 0.14 (p less than 0.01). EET and DET yielded concordant (positive versus negative) results in 41 of 57 (71%) patients off and in 35 of 57 (61%) on therapy (p = NS). In the subgroup of 38 patients with both positive DET and EET without treatment, the therapy-induced variations in exercise time were significantly correlated with the variations in dipyridamole time (r = 0.5; p less than 0.01), not with variations in wall motion score index (r = 0.3; p = NS).


CONCLUSIONS
1) Antianginal therapy can protect from dipyridamole-induced ischemia and 2) the therapy-induced changes in DET response parallel variations in exercise tolerance and might be useful for the objective, exercise-independent assessment of the therapy efficacy.
Lattanzi
F
F
C.N.R. Clinical Physiology Institute, University of Pisa, Italy.
Picano
E
E
Bolognese
L
L
Piccinino
C
C
Sarasso
G
G
Orlandini
A
A
L'Abbate
A
A
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000787:Angina Pectoris / Q000188:drug therapy; D003327:Coronary Disease / Q000000981:diagnostic imaging*; D004176:Dipyridamole; D004452:Echocardiography; D004562:Electrocardiography; D005069:Evaluation Studies as Topic; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D014665:Vasodilator Agents / Q000627:therapeutic use*
D000319:Adrenergic beta-Antagonists; D014665:Vasodilator Agents; D004176:Dipyridamole