Effects of diaspirin crosslinked haemoglobin during coronary angioplasty in the swine.

OBJECTIVE: Percutaneous transluminal coronary angioplasty produces a transient interruption of coronary blood flow during balloon inflation, giving rise to temporary regional myocardial ischaemia. Diaspirin crosslinked haemoglobin (DCLHbTM) transports oxygen in a similar way to whole blood and can be perfused through the angioplasty catheter during balloon occlusion. The aim of this study was to test the hypothesis that DCLHb may increase myocardial oxygenation and reduce myocardial ischaemia during coronary angioplasty. METHODS: The effect of DCLHb on cardiac function was measured in diazepam sedated swine. Mean arterial blood pressure, peak systolic left intraventricular pressure, maximum rate of left ventricular pressure development (dP/dtmax), pressure-rate product, cardiac output (CO), and ECG were monitored continuously. Variables were compared during control, during 1 min balloon occlusion of the proximal left anterior descending coronary artery with a 2.5-3.5 F angioplasty catheter, during 1 min of DCLHb perfusion (40 ml.min-1) without balloon occlusion, and during 4 min balloon occlusion with DCLHb perfusion (40 ml.min-1) of the occluded region. Measurements were made during balloon occlusion plus DCLHb at 1 min (B + D1), 2 min (B + D2), and 4 min (B + D4). RESULTS: Balloon occlusion decreased cardiac function as compared to control: arterial blood pressure -16%, intraventricular pressure -14%, dP/dtmax -34%, and pressure-rate product -40%. DCLHb alone did not significantly change haemodynamic measurements from control. At B + D4 haemodynamic variables were increased as compared to balloon occlusion alone: arterial blood pressure +32%, intraventricular pressure +29%, dP/dtmax +20%, and pressure-rate product +19%. Only intraventricular pressure and mean arterial pressure were increased compared to control. The S-T segment of the ECG was depressed by 0.109(SEM 0.019) mV during balloon occlusion without DCLHb, while only decreasing by 0.069(0.027) mV at B + D1, by 0.046(0.018) mV at B + D2, and by 0.058(0.018) mV at B + D4. CONCLUSIONS: There is an improvement in cardiac function and a lessening of S-T segment depression during percutaneous transluminal coronary angioplasty balloon occlusion with DCLHb perfusion.

Effects of diasprin cross-linked hemoglobin (DCLHb) on cardiac function and ECG in the swine.

The effects of DCLHb on cardiac function were measured in diazepam sedated (2-4 mg/min) swine. Mean arterial blood pressure (MAP), peak systolic left ventricular pressure (IVP), rate of left ventricular pressure development (dP/dt), pressure rate product (PRP), cardiac output (CO), and ECG were monitored continuously. Hemodynamic parameters were compared during control, DCLHb infusion (40 ml/min), one minute balloon occlusion (BO) of the proximal left anterior descending coronary artery (LAD) with a 2.5-3.5 F, 20 mm balloon angioplasty catheter, and four minute balloon occlusion with DCLHb (BO + DCLHb) perfusion (40 ml/min) of the LAD occluded region. Control hemodynamic values were as follows; MAP 91 +/- 6 mmHg, IVP 102 +/- 6 mmHg, dP/dt 2519 +/- 351 mmHg/min, PRP 15809 +/- 1515 mmHg.min, and CO 2.72 +/- 0.29 L/min. There was a significant reduction in cardiac function with BO as compared to control; MAP 16% decreases, IVP 14% decreases, dP/dt 34% decreases, and PRP 40% decreases. In contrast BO + DCLHb significantly increased all measurements of cardiac function, with the exception of CO as compared to control; MAP 32% increases, IVP 29% increases, dP/dt 20% increases, and PRP 19% increases. The S-T segment of the ECG was depressed by a significant 0.134 +/- 0.006 mv from control during BO. There was a significant decrease 0.093 +/- 0.045 mv in the BO + DCLHb group. These data demonstrate an increase in cardiac function and a decrease in S-T segment depression during balloon occlusion with DCLHb perfusion. Further studies are needed to define the mechanism of action of DCLHb mediated increases in cardiac function.