ischaemic preconditioning of the human heart. - Leicester Research ...

The apparent discrepancy bet,.,,,
een results, obtained with non cardiople-ic and
cardioplcgic techniques could be reconciled if one takes into account one possiNe
hypothesis - that pleconditioning, and its salutary effects, are only obsen, ed in
situations of unprotected ischaemia With this in mind, the alms of this ýtudv were
to investu,
gate vAether ischaemic preconditioning with " min ischaernia f6flo-wed by
min reperfusion is protective in patients undergoing coronary artery hypi-,,; gratl
(CABG) surgery with cardiopulmonary bypass using cardioplegin and ventricular
fibrillation techniques and in patients Undergoing CABG on the beating heart without
card iopul monary bypass, and (11) to elucidate the underlying cause of an), protection
7.1 METHODS
7.2.1 lit Vivo Studies
Patient selection and Study groups. 12() patients with -%table angina operated
on by a single surgeon (NIG) accepted to enter the study They Nvere divided in those
to be operated on using card iopu I monary bypass, (CPB) (ic on-ptimp) and exhibitim,
1> -1
three vessel coronary disease (n-80) and those to be operated on the beating heart
without CPB (ic off-pump) and having single or double vessel coronary arler)'
0- 0-
disease (n-40) Patients in the CPB group Nvere randomised using computer generated
II
random table to be operated on (i) using card iopu Imonary bypass (CPB) and
intermittent cross clamp fibrillation + ischaemic preconditioning (n 20 in each
subgroup) or (ii) with cold blood cardioplegia - ischaemic preconditionim, (n 20 in
0 --
each subgroup) Similarly, patients in the beating heart without CPB group were
randomised
to have or not have ischaernic preconditioning (n 20 in each subgrOLIJ)ý
Ischaernic preconditioning was induced by clamping the ascending aoria fior ',
minutes at . 37 "C when CPB xas used or by occlusion of the coronary arterý to he
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