Ms. Jahania et al., Ischemic preconditioning does not acutely improve load-insensitive parameters of contractility in in vivo stunned porcine myocardium, J THOR SURG, 117(4), 1999, pp. 810-817
Citations number
30
Categorie Soggetti
Cardiovascular & Respiratory Systems","Cardiovascular & Hematology Research
Objective: Ischemic preconditioning has been shown to have no beneficial ef
fect on segment shortening in in vivo regionally stunned myocardium, The pu
rpose of this study was to determine whether ischemic preconditioning impro
ves the recovery of postischemic ventricular function when contractility is
assessed by load-insensitive measurements including end-systolic pressure
length relations, preload recruitable stroke work, and preload recruitable
stroke work area in in vivo regionally stunned porcine myocardium. Methods:
Open chest, pentobarbital-anesthetized pigs were used. Regional ventricula
r function was monitored by measurements of segment shortening, stroke work
, end systolic pressure length relations, preload recruitable stroke work,
and preload recruitable stroke work area. The control group was submitted t
o 15 minutes of left anterior descending coronary artery occlusion and 3 ho
urs of reperfusion, The preconditioned group underwent 2 cycles of 5-minute
left anterior descending coronary artery occlusion and 10-minute reperfusi
on before 15 minutes of occlusion, Results: There was no infarct in either
group. The preconditioning protocol significantly depressed preischemic seg
ment shortening but not regional stroke work, Ischemic preconditioning had
no significant beneficial effect on regional stroke work, end-systolic pres
sure length relations, preload recruitable stroke work, or preload recruita
ble stroke work area. Conclusions: These results confirm that ischemic prec
onditioning does not ameliorate in vivo porcine myocardial stunning and ind
icate that ischemic preconditioning may have a limited cardioprotective rol
e during cardiac operation.