[Tolerance of amlodipine in left ventricular dysfunction of ischemic origin]

The aim of this study was to assess the effects of amlodipine on left ventricular function at rest and on effort, at least 30 days after myocardial infarction. The 30 patients included in the study had resting isotopic ejection fractions of 40 to 60%. At inclusion and after 15 days treatment with 10 mg of amlodipine, the patients underwent exercise stress testing with a standard Bruce protocol and resting and exercise isotopic left ventricular ejection fractions were measured. The association of betablockers was allowed but vasodilator therapy was prohibited. During the second exercise stress test, the duration of exercise increased (437 +/- 167 to 518 +/- 154 s; p < 0.002) and the work level rose from 140 +/- 56 to 169 +/- 60 Watts; p < 0.04. The number of electrically positive tests did not change significantly (33 vs 26.7%; NS). The resting ejection fraction did not increase after 15 days treatment with amlodipine (47.4 +/- 6.7 vs 48.3 +/- 8.9%; NS). Similar results were observed with respect to the exercise ejection fraction (51.4 +/- 10.4 vs 52.6 +/- 8.6%; NS). These patients may however be divided into two subgroups. In the first subgroup of 10 patients, the resting ejection fraction rose by more than 5% with amlodipine whereas the exercise ejection fraction remained unchanged (54.4 +/- 7.7% vs 54.5 +/- 7.5% with amlodipine). In the second subgroup of 20 patients, the resting ejection fraction decreased slightly with amlodipine (48 +/- 6.9% vs 45.3 +/- 8%; p = 0.04) but increased significantly on exercise (45.3 +/- 8% vs 51.7 +/- 9.1%; p < 0.0002). Therefore, amlodipine, a new generation calcium antagonist, does not induce any deleterious effect after myocardial infarction with mild left ventricular dysfunction.