TY - JOUR
T1 - The influence of infused calcium on the postischemic myocardium
AU - Whitman, Glenn
AU - Robinson, Murray
AU - Kieval, Robert
AU - Baker, Donald
AU - Harken, Alden
N1 - Funding Information:
’ Supported in part by NIH Grant HL22315. *Glenn Whitman, M.D. is under fellowship training support by the American College of Chest Physicians.
PY - 1984/11
Y1 - 1984/11
N2 - Despite evidence for calcium-induced damage in the postischemic myocardium, calcium remains a frequently used inotropic agent following cardiopulmonary bypass surgery with cardioplegic arrest. The purpose of this study was (1) to challenge the postischemic myocardium with incremental doses of ionized calcium, and (2) to relate postischemic calcium reperfusion concentration to final recovery of left ventricular contractile function. Rabbit hearts (N = 38) were perfused and equipped with a ventricular balloon to monitor developed pressure (DP) ±dp/dt, and left ventricular end diastolic pressure (LVEDP). Hearts underwent 40 min of global ischemia. Hearts were then assigned to one of four groups to receive a variable calcium concentration (0.6, 1.2, 2.5, 5.0 mM) for the initial 5 min of reperfusion followed by 55 min of reperfusion (Ca+2 = 1.25 mM). No differences were found between groups for final recovery of DP ±dp/dt, or final LVEDP. It was concluded that: (1) within the physiologic range, variable calcium infusions during the first 5 min of postischemic reperfusion do not impair final recovery of LV contractile function, (2) irreversible partial recovery of left ventricular function appears due to mechanisms other than mitochondrial or myofibrillar calcium loading during reperfusion, and (3) infused calcium is a safe inotropic agent even in the postischemic myocardium.
AB - Despite evidence for calcium-induced damage in the postischemic myocardium, calcium remains a frequently used inotropic agent following cardiopulmonary bypass surgery with cardioplegic arrest. The purpose of this study was (1) to challenge the postischemic myocardium with incremental doses of ionized calcium, and (2) to relate postischemic calcium reperfusion concentration to final recovery of left ventricular contractile function. Rabbit hearts (N = 38) were perfused and equipped with a ventricular balloon to monitor developed pressure (DP) ±dp/dt, and left ventricular end diastolic pressure (LVEDP). Hearts underwent 40 min of global ischemia. Hearts were then assigned to one of four groups to receive a variable calcium concentration (0.6, 1.2, 2.5, 5.0 mM) for the initial 5 min of reperfusion followed by 55 min of reperfusion (Ca+2 = 1.25 mM). No differences were found between groups for final recovery of DP ±dp/dt, or final LVEDP. It was concluded that: (1) within the physiologic range, variable calcium infusions during the first 5 min of postischemic reperfusion do not impair final recovery of LV contractile function, (2) irreversible partial recovery of left ventricular function appears due to mechanisms other than mitochondrial or myofibrillar calcium loading during reperfusion, and (3) infused calcium is a safe inotropic agent even in the postischemic myocardium.
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U2 - 10.1016/0022-4804(84)90199-9
DO - 10.1016/0022-4804(84)90199-9
M3 - Article
C2 - 6492777
AN - SCOPUS:0021749465
SN - 0022-4804
VL - 37
SP - 348
EP - 353
JO - Journal of Surgical Research
JF - Journal of Surgical Research
IS - 5
ER -