Abstract
Diltiazem was evaluated as an adjunct to cold blood potassium cardioplegia in 63 patients undergoing elective coronary artery bypass grafting. The dual-phase study compared incrementally increasing doses (50, 100, and 150 μg/kg) of diltiazem using a single-blind, randomized schedule with an equivalent volume of placebo added to each of three infusions of cold (10°C ± 2°C) blood containing potassium chloride at 25 mEq/L for the initial infusion (400 ml) and at 12 mEq/L for the next two infusions (300 ml each). Observations included a number of operative variables, creatine kinase (CK)-MB curves, two-dimensional echocardiography, and pulsed Doppler sonography before operation and on postoperative days 1 and 5. Pulmonary artery thermistor catheter responses were observed for 16 hours postoperatively, as were left ventricular micromanometer-tipped catheter responses in 7 patients. As the dose of diltiazem was increased, there was increasing time to atrioventricular node refunction (23.6 to 62.0 minutes). Diltiazem at 100 (μg/kg (D-100) resulted in a significantly lower peak CK-MB activity than its placebo. Peak – dp/dt increased in treated patients and decreased in patients given the placebo. The cardiac index in D-100 patients was greater on the first postoperative day than pre-operatively. The stroke index returned to the control level by the fifth postoperative day in D-50 and D-100 patients only, and it remained depressed in placebo patients. Although few benefits were realized from the addition of diltiazem to cold blood potassium cardioplegia, there was dose-related prolongation of the atrioventricular node recovery time, which required cardiac pacing and thus was associated with its attendant risks.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.