Lethal ventricular arrhythmias (VT/VF) are serious complications after resuscitation of severe hemorrhagic shock (HS). To investigate mechanisms of arrhythmogenesis after HS and a role of two different concentration of oxygenated liposome-encapsulated human hemoglobin (LHb [Hgb=6g] or HbV [Hgb=10g]), optical mapping analysis (OMP) and electrophysiological study (EPS) were performed using rat HS model. HS was induced by withdrawing 30% blood from aorta (shock alone). Rats were resuscitated by transfusing saline, 5% albumin (5%ALB), LHb, HbV or oxygenated autologous washed red blood cells (wRBC: n=7, per group). After excising heart, OMP and EPS were performed in isolated Langendorff-perfused hearts. OMP revealed abnormal ventricular conduction delay (VCD) with impaired action potential duration dispersion (APDd) in both ventricles in shock alone, saline, and 5%ALB whereas VCD and APDd were substantially attenuated in LHb, HbV or wRBC (a). VT/VF was easily provoked by burst pacing stimulus to LV in saline and 5%ALB while few VT/VF was induced in LHb, LbV or wRBC (b).
Conclusion:
Ventricular electrical remodeling of abnormal VCD and APDd after HS causes VT/VF. LHb, LbV and wRBC comparably prevent VT/VF possible by attenuating ischemia-reperfusion injury in HS. Especially, even low concentration of hemoglobin in LHb is comparably effective with closely normal concentration of HbV.
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