To assess the potential benefit of hyperosmolar reperfusion induced by mannitol administration in hearts subjected to prolonged global ischemia, 24 canine preparations were subjected to 45 minutes of hypothermic (27°C) cardioplegic arrest and normothermic reperfusion. The hearts were isolated in situ after cardiopulmonary bypass was initiated and control left ventricular function was assessed (developed pressure and dP/dt), and coronary blood flow (CBF) and intramyocardial gas tensions were measured. The hearts were divided into three equal groups: hearts in group 1 received no mannitol during reperfusion; hearts in group 2 received sufficient mannitol to elevate reperfusate osmolarity 35 mosmol from the onset of reperfusion; and hearts in group 3 received a similar quantity of mannitol beginning 15 minutes after the onset of reperfusion. Immediate hyperosmolar reperfusion in group 2 resulted in a significantly greater CBF at 5 minutes (224 ± 14% control vs 142 ± 14% control in group 1), with a higher endocardial/epicardial flow ratio (1.24 ± 0.09 vs 0.94 ± 0.11 in group 1) and better-preserved left ventricular function after 45 minutes (90 ± 2% control vs 79 ± 3% in group 1 and 80 ± 2% in group 3). In addition, both group of mannitol treated hearts had significantly less formation of myocardial edema and improved structural preservation compared with the non-mannitol-treated hearts. These data confirm the benefits of hyperosmolar, postischemic reperfusion with mannitol and suggest that administration of mannitol at the onset of reperfusion results in improved myocardial protection.
|Original language||English (US)|
|Issue number||2 II|
|State||Published - Oct 10 1980|
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine
- Physiology (medical)