At a dosage of 75 mg b.i.d., gallopamil retard represents a suitable medication for the treatment of both symptomatic and asymptomatic ischemic episodes, as could be demonstrated in patients with coronary heart disease ascertained by angiography, positive exercise testing, and more than five ischemic episodes in Holter monitoring over 48 h. The results of our study furnish proof that more than 60% of ischemic episodes recorded in patients with stable angina pectoris during Holter monitoring over 48 h, have been asymptomatic, i.e., silent. It must thus be postulated that effective antianginal therapy must be able to suppress both symptomatic and asymptomatic ischemic episodes. This should be documented by Holter monitoring over 48 h. It has not been established yet which criteria: duration of ST-segment depression, frequency of ischemic episodes, or area integral of ST-segment depression, furnish the most adequate parameters for assessment of ischemia. Assessment of the three criteria, taken together, is likely to be most reliable and should thus, in particular, be adhered to in evidencing efficacy in an antianginal drug trial.