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

grafted for the same period and then reperfused for another 5-minutes betlore
proceeding with bypass grafting. Patients with low ejection fractions (EF - 30`0,
unstable angina, recent myocardial infarctions (-: I month), additional cardiac
discascs, severc non-cardiac discascs, diabetcs, and (in mcdication that includcd ATP-
dependent potassium channel (K,., i-p) openers were excluded The study %vas approved
by the local ethics committee and all patients gave written informed consent to the
study. Pre-operative characteristics of the patients are highlighted in Table 71
7 2.2 Operative Procedure
Anaesthetic technique was standardized for all patients Anaesthesia vvas induced bN,
fentanyl and maintained with enflurane in all patients All operations were perflormed
through a median sternotomy and full heparinisation (3 mL,, Ik-_g Iv)
CIIB was
conducted with non-pul. %atile perfusion flow (2 2-2 4 I! mlmlm2) with ascending aomic
cannulation and 2-staged venous cannulation and moderate systemic hypothermia
(32'C). When cardiac arrest was achieved with cold blood (0 10-C) caudiople, 'j. 1,
1000 mL of the solution (composition in mmoUl. 16 61-1.0,2 CaCl_ 20 KCI,
147 NaCl. 1.0 procaine HCI, ph 7.40) was mixed with blood from the pump in a ratio
of II and injected into the aortic root immediately afler aortic cross-claniping to
obtain a myocardial temperature of 12'C to 15'C An additional dose of 500 nil. (it'
cardioplegla . vas injected after 30min of ischaemia. In the group in which intermittent
aortic cross-clamp fibrillation was used, reperfusion was carried out flor ., nunwe,;
between each period One single distal coronai), ariM, anastomosis was performed
Cý
during each ischaernic period Proximal anastomosis were completed on the heatill-
heart with aortic partial occlusion clamp in all groups
146