Biomaterial Database

Failure of blood cardioplegia to protect myocardium at lower temperatures. 1982

G J Magovern, and J T Flaherty, and V L Gott, and B H Bulkley, and T J Gardner

To assess the effect of temperature, oxygenated blood and crystalloid cardioplegic solutions (CPs) at infusion temperatures of 20 degrees C, 10 degrees C and 4 degrees C were compared. The amount of potassium in each CP was 25 mEq/l. There were six study groups with seven canine hearts in each group, all of which were subjected to 90 minutes of global ischemia at 20 degrees C, 10 degrees C or 4 degrees C, followed by 45 minutes of normothermic reperfusion. During ischemia, either blood or crystalloid CP was given every 30 minutes. With each infusion, any change in myocardial oxygen tension was recorded using mass spectrometry, and oxygen consumption (MVO2) was calculated. Left ventricular (LV) function was assessed before and after ischemia in all hearts by measuring isovolumic developed pressure using an intraventricular balloon. Injection of 20 degrees C blood CP resulted in a mean increase in intramyocardial oxygen tension (PO2) of 7 mm Hg. At 10 degrees C or 4 degrees C, blood CP infusions did not cause a significant increase in intramyocardial PO2, while with crystalloid CP, intramyocardial PO2 did not increase at any of the three infusion temperatures. The mean MVO2 with each blood CP injection, expressed as ml O2/100 g LV wet weight, was 16.5 +/- 0.8 for 20 degrees C blood, 4.1 +/- 0.3 for 10 degrees C blood and 3.5 +/- 0.4 for 4 degrees C blood (p less than 0.001, 20 degrees C blood vs 10 degrees C and 4 degrees C blood). MVO2 with each crystalloid CP injection was 0.9 +/- 0.1 for 20 degrees C CP, 0.8 +/- 0.1 for 10 degrees C CP, and 0.7 +/- 0.1 for 4 degrees C CP. Recovery of developed pressure after 45 minutes of reperfusion, expressed as a percentage of preischemic control, was 76.0 +/- 3.4% or 20 degrees C blood CP, 65.6 +/- 2.3% for 10 degrees C blood CP, and 54.0 +/- 2.7% for 4 degrees C blood CP (p less than 0.05, 20 degrees C blood CP vs 10 degrees C and 4 degrees C blood CP). Recovery of developed pressure, also expressed as a percentage of preischemic control, was 56.6 +/- 1.4% for 20 degrees C crystalloid CP, 72.9 +/- 3.0% for 10 degrees C crystalloid CP, and 72.0 +/- 2.3% for 4 degrees C crystalloid CP (p less than 0.05, 20 degrees C crystalloid CP vs 10 degrees C and 4 degrees C crystalloid CP). These data show that blood CP is most effective when infused at 20 degrees C. The use of 10 degrees C blood CP enhanced myocardial cooling, but was of no additional benefit, presumably because there was little oxygen delivery. Blood CP at 4 degrees C resulted in significantly poorer preservation of LV function. Crystalloid CP infused at either 4 degrees C or 10 degrees C was as effective as 20 degrees C blood CP, despite the absence of oxygen use by hearts treated with crystalloid CP.

UI	MeSH Term	Description	Entries
D007036	Hypothermia, Induced	Abnormally low BODY TEMPERATURE that is intentionally induced in warm-blooded animals by artificial means. In humans, mild or moderate hypothermia has been used to reduce tissue damages, particularly after cardiac or spinal cord injuries and during subsequent surgeries.	Induced Hypothermia,Mild Hypothermia, Induced,Moderate Hypothermia, Induced,Targeted Temperature Management,Therapeutic Hypothermia,Hypothermia, Therapeutic,Induced Mild Hypothermia,Induced Mild Hypothermias,Induced Moderate Hypothermia,Induced Moderate Hypothermias,Mild Hypothermias, Induced,Moderate Hypothermias, Induced,Targeted Temperature Managements
D007552	Isotonic Solutions	Solutions having the same osmotic pressure as blood serum, or another solution with which they are compared. (From Grant & Hackh's Chemical Dictionary, 5th ed & Dorland, 28th ed)	Solutions, Isotonic
D009206	Myocardium	The muscle tissue of the HEART. It is composed of striated, involuntary muscle cells (MYOCYTES, CARDIAC) connected to form the contractile pump to generate blood flow.	Muscle, Cardiac,Muscle, Heart,Cardiac Muscle,Myocardia,Cardiac Muscles,Heart Muscle,Heart Muscles,Muscles, Cardiac,Muscles, Heart
D010100	Oxygen	An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.	Dioxygen,Oxygen-16,Oxygen 16
D010101	Oxygen Consumption	The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)	Consumption, Oxygen,Consumptions, Oxygen,Oxygen Consumptions
D010313	Partial Pressure	The pressure that would be exerted by one component of a mixture of gases if it were present alone in a container. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Partial Pressures,Pressure, Partial,Pressures, Partial
D011188	Potassium	An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
D001769	Blood	The body fluid that circulates in the vascular system (BLOOD VESSELS). Whole blood includes PLASMA and BLOOD CELLS.
D002245	Carbon Dioxide	A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.	Carbonic Anhydride,Anhydride, Carbonic,Dioxide, Carbon
D004285	Dogs	The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)	Canis familiaris,Dog