OBJECTIVE: To research the myocardium stress diskinesia as another possible cause of the silent myocardium ischemia induced by exercise testing stress and to analyze the efficacy of the myocytic calcium blocker diltiazem for normalization of previously positive testing. METHOD: In October 2004, ten patients without symptoms of coronary artery disease, presenting positive exercise testing, defined by ST segment depression, with neither precordial pain or arrhythmia during testing (six males - 60%; ages between 42 and 71 years old, mean 58.2 years), were treated with 90 mg of diltiazem in three times daily and re-studied five days after the first examination. Treadmill electrocardiography exercise testing was performed using the Bruce protocol. RESULTS: Diltiazem administration blocked the ST segment depression, both J point (mean 2.1 ± 0.3mm, in the control and 0.0 depression with treatment; p<0.001) and Y point (mean 1.65 ± 0.7 mm in the control and 0.0 depression with treatment; p<0.001). The Heart rate variations were not significant (p>0.05), with mean values of 156.1 ±12.3 in the control and 151.6 ±23.4 bpm with treatment). CONCLUSION: The administration of the myocytic calcium inhibitor diltiazem impeded the occurrence of the silent ST segment depression, previously induced by exercise stress testing in patients without symptoms of coronary arterial disease, confirming the involvement of the myocardium contraction diskinesia in the phenomenon genesis.
Coronary disease; Myocardial ischemia; Electrocardiography; Exercise test
