Twenty-four hour blood pressure monitoring in the evaluation of once daily treatment of essential hypertension with captopril.

A new ambulatory blood pressure monitoring system is being used in a study of once daily treatment of essential hypertension with captopril. The Instruments for Cardiac Research system consists of a small, battery powered monitoring device carried by the patient and a base unit containing a microcomputer. On completion of the 24-hour monitoring schedule, the base unit extracts the data from the portable unit. The base unit can then display the data in tabular or graphic form on its printer, or record it on a built in microcassette recorder. The data can readily be transferred to a main frame computer for subsequent analysis. Ninety-eight percent of the patients wore the unit initially with only an additional 2% refusals at 3 subsequent evaluations during the 5 month trial. Eighty-six percent of the tapes had one-half or more of the readings.