Ventricular function was studied acutely before and after internal mammary artery implantation in dogs with the following findings: (1) A single ventricular function study alone did not significantly alter the ventricular function curve obtained 45 minutes later. (2) Single IMA implant and two tunnels without implants appeared to depress ventricular function, although the depression was not significant in degree or frequency when compared with control values. (3) Double internal mammary artery implants depressed ventricular function more than 10% in eight of ten animals studied which was significantly more frequent than in control group I (P< 0.05). In addition, the magnitude of the depression (average 18.3%) was significant when compared with pre-implant control values (P<0.05).
- © 1969 American Heart Association, Inc.