Effects of vasoactive drugs on postoperative coronary bypass flow: a new technique

This study aimed to investigate the influence of vasoactive drugs, including a calcium channel blocker, nitroglycerine, and a beta-blocker, often used after coronary artery bypass grafting (CABG). Measurements were taken using a new, completely implantable, mini-Doppler system. The probes were implanted during CABG, led outside through the thoracic wall, and removed 3 days after the operation by a simple pull.

The mean Doppler flow increased dramatically in the calcium channel blocker and the nitroglycerine groups (P = 0.002) and decreased slightly in the beta-blocker group (P = 0.015). Mean arterial pressure decreased significantly in all three groups. Heart rate decreased in the beta-blocker group (P = 0.002). Changes in the other hemodynamic variables measured were not significant; there were no changes in the control group. Doppler sonographic monitoring of bypass diameters did not show any changes.

This is the first study to measure the influence of vasoactive drugs directly and online after CABG. From our experience of more than 40 implantations, we conclude that our method is easy to use and reliable and will help improve the therapeutic regimen for patients after CABG.