Gw. Laub et al., ESMOLOL AND PERCUTANEOUS CARDIOPULMONARY BYPASS ENHANCE MYOCARDIAL SALVAGE DURING ISCHEMIA IN A DOG-MODEL, Journal of thoracic and cardiovascular surgery, 111(5), 1996, pp. 1085-1091
Despite recent advances in techniques of reperfusion for acute myocard
ial ischemia, myocardial salvage remains suboptimal. beta-Blockers hav
e been shown to limit infarct size during acute ischemia, but their ne
gative inotropic properties have limited their use. Cardiopulmonary by
pass is an attractive technique for cardiac resuscitation because it c
an stabilize a hemodynamically compromised patient and potentially red
uce myocardial oxygen consumption. In an attempt to maximize myocardia
l salvage in the setting of acute ischemia, the combination of esmolol
, an ultrashort-acting beta-blocker, with percutaneous cardiopulmonary
bypass was evaluated. Four groups of instrumented dogs underwent 2 ho
urs of myocardial ischemia induced by occlusion of the proximal left a
nterior descending coronary artery, followed by 1 hour of reperfusion.
Throughout the period of ischemia and reperfusion, esmolol plus percu
taneous cardiopulmonary bypass was compared with esmolol alone, percut
aneous cardiopulmonary bypass alone, and control conditions. After the
reperfusion period, the extent of infarction of the left ventricle at
risk was determined. Four animals had intractable arrhythmias: one in
the esmolol plus bypass group, one in the esmolol group, and two in t
he control group. The extent of infarction of the left ventricle at ri
sk was significantly reduced in the esmolol plus bypass group (30%) co
mpared with bypass alone (52%), with esmolol alone (54%), and with the
control groups (59%; p < 0.05). We conclude that in this experimental
model the combination of esmolol with bypass improves myocardial salv
age after ischemia and reperfusion.