Evidence of improved microvascular perfusion when using antegrade and retrograde cardioplegia.
BACKGROUND
The maximum degree of microvascular distribution of cardioplegic solution is considered important to achieve optimum myocardial protection. This study attempts to demonstrate that the addition of retrograde cardioplegia to antegrade cardioplegia improves overall microvascular perfusion.


METHODS
Explanted human hearts (n = 6) were treated with cold cardioplegic arrest and bicaval cardiectomy. Blood cardioplegia (37 degrees C) containing colored microspheres (color A for antegrade, color B for retrograde) was simultaneously infused antegrade at a pressure of 80 mm Hg and retrograde at a pressure of 40 mm Hg for 2 minutes. The ventricular myocardium was then sampled at three sites to determine absolute and relative cardioplegic microvascular flow.


RESULTS
Of the total microvascular capillary flow, 27% to 32% was found to be the contribution of retrogradely delivered cardioplegia.


CONCLUSIONS
Despite being delivered simultaneously and at a lower pressure, retrograde cardioplegia contributed substantially to overall microvascular perfusion. This suggests that antegrade cardioplegia alone does not perfuse all available myocardial capillaries and that the addition of retrograde cardioplegia enhances overall microvascular distribution and perfusion.
Department of Surgery, University of California Los Angeles Medical Center 90095-1741, USA.
R N
RN
Gates
J
J
Lee
H
H
Laks
D C
DC
Drinkwater
E
E
Rhudis
A S
AS
Aharon
J Y
JY
Chung
P A
PA
Chang
D002314:Cardioplegic Solutions / Q000493:pharmacokinetics*; D003326:Coronary Circulation; D004353:Drug Evaluation, Preclinical; D006324:Heart Arrest, Induced / Q000379:methods*; D006801:Humans; D008833:Microcirculation; D008863:Microspheres; D011312:Pressure; D013997:Time Factors; D014018:Tissue Distribution
D002314:Cardioplegic Solutions