Liposome‐encapsulated hemoglobin vesicles (HbV) can serve as a blood substitute with oxygen‐carrying capacity comparable to that of human blood and lethal hemorrhage is associated with lethal arrhythmias. To investigate the resuscitation effect of HbV on lethal hemorrhage and anti‐arrhythmogenesis, we performed optical mapping analysis (OMP) and electrophysiological study (EPS) in graded blood exchange (85% blood loss) in the rat model. We also measured cardiac autonomic activity, as assessed by heart rate variability (HRV), and changes in plasma norepinephrine and left ventricle ejection fraction (LVEF) by echocardiography. Pathological study on Connexin43 was performed. A 5% albumin (ALB group), washed rat erythrocytes (wRBC group), and HbV (HbV group) were used as a resuscitation fluid. The survival effects over 24 hours were examined. All rats died in the ALB group, whereas almost all survived for 24‐hours period in wRBC and HbV groups. OMP showed impaired action potential duration dispersion (APDd) in the ALB group, whereas normal APDs in HbV and wRBC groups. Lethal arrhythmias were induced by EPS in the ALB group, but not in wRBC and HbV groups. HRV indices, LVEF, Connexin43 were preserved in HbV and wRBC groups. Lethal hemorrhage causes lethal arrhythmias in the presence of impaired APDd. HbV acutely rescues lethal hemorrhage by preventing lethal arrhythmias and preserving arrhythmogenic factors.

Introduction: Prolonged low blood pressure <40 mmHg in hemorrhagic shock (HS) causes irreversible heart dysfunction, ‘Shock Heart Syndrome’ (SHS), which is associated with lethal arrhythmias (ventricular tachycardia or ventricular fibrillation [VT/VF]) leading to a poor prognosis. Methods: To investigate whether the liposome-encapsulated human hemoglobin oxygen carrier (HbV) is comparable in effectiveness to autologous washed red blood cells (wRBCs) for improving arrhythmogenic properties in SHS, optical mapping analysis (OMP), electrophysiological study (EPS), and pathological examinations were performed in Sprague-Dawley rat hearts obtained from rats subjected to acute HS by withdrawing 30% of total blood volume. After acute HS, the rats were immediately resuscitated by transfusing exactly the same amount of saline (SAL), 5% albumin (5% ALB), HbV, or wRBCs. After excising the heart, OMP and EPS were performed in Langendorff-perfused hearts. Results: OMP showed a tendency for abnormal conduction and significantly impaired action potential duration dispersion (APDd) in both ventricles with SAL and 5% ALB. In contrast, myocardial conduction and APDd were substantially preserved with HbV and wRBCs. Sustained VT/VF was easily provoked by a burst pacing stimulus to the left ventricle with SAL and 5% ALB. No VT/VF was induced with HbV and wRBCs. Pathology showed myocardial structural damage characterized by worse myocardial cell damage and Connexin43 with SAL and 5% ALB, whereas it was attenuated with HbV and wRBCs. Conclusions: Ventricular structural remodeling after HS causes VT/VF in the presence of APDd. Transfusion of HbV prevents VT/VF, similarly to transfusion of wRBCs, by preventing electrical remodeling and preserving myocardial structures in HS-induced SHS.

Background: Sodium-glucose transporter-2 inhibitor (SGLT2) is reported to have anti-atherosclerotic effects in experiment. However, the effect of SGLT2 on endothelial function (ECF) in humans is not fully investigated. Method and Results: We measured ECF in 11 diabetic patients with coronary artery disease (CAD) and poor control of diabetics (HbA1c >7%; 75 8 years old) by simultaneously measuring brachial artery flow-mediated dilation (FMD) and EndoPAT2000 (measuring RHI). FMD and RHI were measured before and after mean periods of 4-week treatment of Canagliflozin (100 mg per every other day).

Background: Artificial oxygen carriers (HbV) can treat hemorrhagic shock with lethal arrhythmias (VT/VF). No reports exist on subacute HbV's effects.Methods: Acute and subacute resuscitation effects with anti-arrhythmogenesis of HbV were studied in 85% blood exchange rat model (85%-Model). Lethal 85%-Model was created by bone marrow transfusion and femoral artery bleeding in 80 SD rats in HbV-administered group (HbV-group), washed erythrocyte-administered group (wRBC-group), and 5% albumin-administered group (ALB-group). Survival rates, anti-arrhythmic efficacy by optical mapping system (OMP) with electrophysiological study (EPS) in Langendorff heart, cardiac autonomic activity by heart rate variability (HRV) and ventricular arrhythmias by 24-h electrocardiogram telemetry monitoring (24 h-ECG) in awake, and left ventricular function by echocardiography (left ventricular ejection fraction [LVEF]) were measured.Results: All rats in HbV-and wRBC-groups survived for 4 weeks, whereas no rats in ALB-group. HbV and wRBC acutely suppressed VT/VF in Langendorff heart through ameliorating action potential duration dispersion (APDd) analyzed by OMP with EPS. For subacute analysis, 50% blood exchange by 5% albumin was used (ALB-group 50). Subacute salutary effect on APDd and VT/VF inducibility was confirmed in HbV-and wRBC-groups. 24 h-ECG showed that HbV and wRBC suppressed none-sustained ventricular tachycardia (NSVT) and sympathetic component of HRV (LF/HF) with preserved LVEF (HbV-group, wRBC-group vs. ALB-

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Introduction: Prolonged blood pressure < 40 mmHg in hemorrhagic shock (HS) causes irreversible heart dysfunction, “Shock Heart Syndrome” (SHS), which is associated with lethal arrhythmias (VT/VF). Methods: To investigate whether liposome-encapsulated human hemoglobin (HbV) is comparable to washed red blood cells (wRBCs) for improving arrhythmogenesis in SHS in either acute or chronic phase, optical mapping analysis (OMP), electrophysiological study (EPS) and pathological examinations were performed in Sprague-Dawley rat hearts, being obtained from both acute and chronic phase when each rat survived. The first, they were subjected to acute HS by withdrawing 30% of total blood volume. After HS, rats were immediately resuscitated by transfusing exactly same amount of 5% albumin (5%ALB, n=13), HbV (n=13), or wRBCs (n=13). All rats in chronic phase survived at least several weeks. After excising heart, OMP and EPS were performed in Langendorff-perfused hearts. Results: In both acute and chronic phase, OMP showed tendency for abnormal conduction and significantly impaired action potential duration dispersion (APDd) in left ventricle with 5%ALB (25±9 / 24±10 ms, Acute / Chronic phase). In contrast, myocardial conduction and APDd were substantially preserved with HbV (14±3 / 13±5 ms) and wRBCs (14±3 / 15±3 ms) as shown in Figure . Sustained VT/VF was easily provoked by burst pacing stimulus to left ventricle with 5%ALB. No VT/VF was induced with HbV and wRBCs. Pathology showed myocardial structural damage characterized by worse myocardial cell damage and Connexin43 with 5%ALB, whereas it was attenuated with HbV and wRBCs in both acute and chronic phase. Conclusions: Ventricular structural remodeling after HS causes VT/VF in the presence of APDd. Transfusion of HbV prevents acutely and chronically VT/VF, similarly to transfusion of wRBCs, by preventing chronic electrical remodeling of APDd and preserving myocardial structures in HS-induced SHS