Effects of simulated clinical cardiopulmonary bypass and cardioplegia on mass of the canine left ventricle.
Myocardial edema is a well-documented response to ischemia and reperfusion in dogs and can be detected as an increase in left ventricular (LV) mass measured echocardiographically. Investigation in human beings has failed to demonstrate similar increases in LV mass after routine cardiac operations. However, direct comparison of these observations is not possible, because dogs have not been studied under conditions of cardiopulmonary bypass (CPB) and global ischemia that rigorously reproduce those of a clinical operation. Accordingly, clinical CPB and global ischemia were simulated in 8 adult dogs. Multisection two-dimensional echocardiograms and a computerized light pen were used to calculate LV volume and mass. The data were analyzed during four periods: before CPB; CPB before cross-clamping; CPB after cross-clamping, and after CPB. Echocardiographic LV mass increased significantly from 89.5 +/- 7.4 gm (before CPB) to 94.6 +/- 8.5 gm (CPB before cross-clamping) (p less than 0.05) and from 94.6 +/- 8.5 gm to 100.4 +/- 8.1 gm (CPB after cross-clamping) (p less than 0.05). Overall, mass increased 13.9% (p less than 0.05). Mean wall thickness increased 0.08 cm (p less than 0.05) overall and correlated with the increase in mass (r = 0.79). Postmortem mass correlated well with late echocardiographic mass (r = 0.95). Interobserver correlation of 98 separate mass determinations was high (r = 0.84) with a coefficient of variation of 10.5%. We conclude that canine LV mass increases significantly with CPB and global ischemia maintained within clinical standards and that human beings and dogs may differ in extent of edema during CPB.
Rosenblum
H M
HM
Haasler
G B
GB
Spotnitz
W D
WD
Lazar
H L
HL
Spotnitz
H M
HM
D000818:Animals; D006332:Cardiomegaly / Q000209:etiology / Q000473:pathology; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D004195:Disease Models, Animal; D004285:Dogs; D004452:Echocardiography; D004489:Edema, Cardiac / Q000209:etiology / Q000473:pathology; D006324:Heart Arrest, Induced / Q000009:adverse effects*; D006352:Heart Ventricles / Q000473:pathology; D009206:Myocardium / Q000473:pathology*