The Journal of Thoracic and Cardiovascular Surgery, Vol 89, 90-96, Copyright © 1985 by The American Association for Thoracic Surgery and The Western Thoracic Surgical Association
Efficacy of crystalloid cardioplegic solutions in patients undergoing myocardial revascularization. Effect of infusion route and regional wall motion on preservation of adenine nucleotide stores
NA Silverman, R Wright, S Levitsky, G Schmitt and H Feinberg
The effect of varying the mode of cardioplegic delivery and the presence of
regional wall motion abnormalities on myocardial protection by crystalloid
cardioplegic solutions was assessed in 68 patients undergoing coronary
artery bypass grafting. Serial transmural biopsy specimens from the left
ventricular apex were assayed for adenosine triphosphate. All patients had
more than 75% stenosis of the left anterior descending coronary artery.
They were prospectively randomized into Groups I and II to receive (I) all
cardioplegic solution infused via the aortic root or (II) reinfusions of
cardioplegic solution given both centrally and through the completed distal
left anterior descending anastomosis. Patients were also stratified as to
the presence of normal (N) or impaired (Ab) apicoanterior regional wall
motion. Inadequate delivery of cardioplegia during ischemia in Group I was
manifested by a 41% (p less than 0.01) depletion of adenosine triphosphate
stores in abnormally contracting myocardium distal to the left anterior
descending stenosis that was not repleted after restoration of coronary
flow and a 27% (p less than 0.05) decline in ATP stores during reperfusion
in myocardium with normal preoperative wall motion. In contrast, nucleotide
stores were preserved at preischemic levels throughout ischemia and
reperfusion in Group II regardless of preoperative wall motion.
Preservation of ATP did not correlate with duration of ischemia, highest
recorded septal temperature, or volume of cardioplegic solution infused.
Two patients in each group had a new perioperative infarction. However, 38%
of patients in Group IAb required transient inotropic support versus 5% in
Group IIAb (p less than 0.05). These data emphasize that reinfusion of
cardioplegic solutions distal to coronary obstructions is mandatory for
optimal myocardial protection during coronary revascularization.
