Hemodynamic measurements and exercise testing to assess the development of tolerance against slow-release isosorbide...

Hemodynamic measurements were carried out during exercise testing with floating catheterization in 12 male patients with multiple-vessel disease and stable angina pectoris after placebo, after acute treatment with 60 mg ISDN, and after 4 weeks treatment with 4 X 60 mg ISDN. The acute effects of ISDN at the maximal comparable workload were a 32% decrease in PAd, a 41% decrease in ST-segment depression, and a 35% increase in maximal workload. After 4 weeks therapy we found an attenuation of the efficacy of ISDN, with only a 12% decrease in PAd, a 33% decrease in ST-segment depression, and an 18% increase in maximal workload.