Cardiovascular effects of a new Ca2+ channel blocker AH-1058, 4-(5H-dibenzo[a,d]cyclo-hepten-5-ylidene)-1-[(E)-3-(3-methoxy-2-nitro)phenyl-2-propenyl]piperidine hydrochloride, were assessed in conscious dogs using a new telemetry system. AH-1058 (0.03, 0.1 and 0.3 mg/kg, i.v.) reduced systolic blood pressure and the maximal upstroke velocity of the left ventricular pressure and increased the heart rate in a dose-dependent manner without affecting the diastolic blood pressure; each of these responses lasted for several hours. These results support the previous knowledge that AH-1058 is a long-lasting cardiodepressive drug. The telemetry system provided important information for predicting favorable clinical effects of AH-1058.