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The purpose of this study was (1) to monitor myocardial high-energy phosphate content and recovery of left ventricular (LV) contractile function following normothermic graded cardiac ischemia and single-dose hypothermic potassium cardioplegia, and (2) to assess the temporal limits of LV functional recovery during single-dose cardioplegia maintained at 17 degrees C. Rabbit hearts (30) were perfused, equipped with an LV balloon, paced at 240 beats/min, and placed in a nuclear magnetic resonance (NMR) magnet. Hearts underwent either graded, global normothermic ischemia or potassium cardioplegia arrest maintained at 17 degrees C for 1 hr. Myocardial high-energy phosphate level, LV contractility, and temperature were monitored continuously. Phosphocreatine (PCr) fell to 10 +/- 2, 2 +/- 1, and 0% of control and ATP to 70 +/- 3, 19 +/- 7, and 0% of control at 10, 40, and 60 min of 37 degrees C ischemia. After 1 hr of reperfusion, regression analysis of final developed pressure (DP) on end ischemic ATP (EIATP) content revealed: DP = 1.02 EIATP + 18 (r = 0.95). Following single-dose cardioplegia, maintained at 17 degrees C, PCr fell to 16 +/- 3% of control at 60 min while ATP fell only to 92 +/- 5% control. With reperfusion, recovery of DP was 100%. It was concluded that (1) PCr serves as an energy buffer for ATP, (2) EIATP predicts recovery of LV function, (3) single-dose cardioplegia maintained at 17 degrees C provides complete myocardial preservation for up to 60 min.
G J Whitman, and
R A Roth, and
R S Kieval, and
A H Harken
January 1993,
Magnetic resonance in medicine,
G J Whitman, and
R A Roth, and
R S Kieval, and
A H Harken
May 1988,
Nihon Geka Gakkai zasshi,
G J Whitman, and
R A Roth, and
R S Kieval, and
A H Harken
February 1988,
Transplantation proceedings,
G J Whitman, and
R A Roth, and
R S Kieval, and
A H Harken
October 1987,
Transplantation proceedings,
G J Whitman, and
R A Roth, and
R S Kieval, and
A H Harken
June 1987,
Transplantation,
G J Whitman, and
R A Roth, and
R S Kieval, and
A H Harken
January 1992,
Nihon Geka Gakkai zasshi,
G J Whitman, and
R A Roth, and
R S Kieval, and
A H Harken
February 1988,
Biochemical and biophysical research communications,
G J Whitman, and
R A Roth, and
R S Kieval, and
A H Harken
June 1991,
Transplant international : official journal of the European Society for Organ Transplantation,
G J Whitman, and
R A Roth, and
R S Kieval, and
A H Harken
January 1997,
Advances in experimental medicine and biology,
G J Whitman, and
R A Roth, and
R S Kieval, and
A H Harken
January 1985,
Cellular and molecular biology,
