Medical College of Wisconsin
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Cardioplegia-induced damage to ischemic immature myocardium is independent of oxygen availability. Ann Thorac Surg 1990 Dec;50(6):934-9



Pubmed ID




Scopus ID

2-s2.0-0025570174   11 Citations


The known benefits of hypothermic pharmacological cardioplegia in protecting the ischemic adult heart may not extend to children. Protection of the ischemic immature rabbit heart with hypothermic Krebs-Henseleit bicarbonate buffer is better than with hypothermic St. Thomas' II cardioplegic solution. We investigated whether the availability of oxygen in the preischemic perfusate is responsible for the increased tolerance to ischemia of immature (7- to 10-day-old) hearts perfused with Krebs buffer in comparison with St. Thomas' II solution immediately before ischemia. After obtaining preischemic control data in the "working" mode, we perfused hearts (n = 8 per group) for 3 minutes with hypothermic (14 degrees C) Krebs buffer or hypothermic St. Thomas' II solution saturated with 0%, 25%, or 95% oxygen. This was followed by 2 hours of global ischemia at 14 degrees C. Hearts were reperfused for 15 minutes in the Langendorff mode and 35 minutes in the working mode, and recovery of function was measured. For preischemic oxygen concentrations of 0%, 25%, and 95%, recovery of aortic flow in hearts protected by hypothermia alone during ischemia was 74% +/- 9%, 82% +/- 4%, and 99% +/- 2% of preischemic values, respectively. In hearts protected by hypothermia plus cardioplegia, the values were 69% +/- 6%, 72% +/- 3%, and 86% +/- 5%, respectively. Thus, at equal oxygen concentrations, recovery of postischemic function was better in hearts protected by hypothermia alone compared with hypothermia plus cardioplegia. We conclude that factors other than oxygen availability are responsible for the damaging effect of St. Thomas' II solution on the ischemic immature rabbit heart.

Author List

Baker JE, Boerboom LE, Olinger GN


John E. Baker PhD Professor in the Surgery department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Calcium Chloride
Cardiac Output
Cardioplegic Solutions
Coronary Circulation
Coronary Disease
Creatine Kinase
Heart Arrest, Induced
Hypothermia, Induced
Isotonic Solutions
Myocardial Reperfusion Injury
Oxygen Consumption
Potassium Chloride
Sodium Chloride
jenkins-FCD Prod-482 91ad8a360b6da540234915ea01ff80e38bfdb40a