The efficacy of cardioplegia in the neonatal heart has been questioned and some studies have suggested that, in the rabbit, multi-dose hypothermic cardioplegia may be damaging. We have therefore compared the protective properties of multi-dose and single-dose cardioplegia in the immature rat heart with normothermic and hypothermic ischemia. Isolated Langendorff perfused hearts (n = 6 per group) from 8-10 day-old rats, were arrested with a single-dose (2 min at the onset of ischemia) or multi-dose (2 min at onset of ischemia and repeatedly throughout ischemia) of warm (37°C) or cold (10°C) St Thomas' Hospital cardioplegic solution. The hearts were then subjected to 1 h of normothermic global ischemia or 24 h of hypothermic ischemia, followed by normothermic reperfusion of 30 min. In the normothermic studies the post-ischemic recovery of left ventricular developed pressure was 44 ± 6% of its pre-ischemic value with single-dose cardioplegia versus 56 ± 4% with multi-dose (cardioplegic infusion every 15 min). In the hypothermic studies the trend was in the opposite direction; the post-ischemic recovery of left ventricular developed pressure was 46 ± 2% in the single-dose group, whereas in the multi-dose (cardioplegic infusion every 6 h) group the recovery was 28 ± 3% (p <0.05). Thus, in accord with other studies in other species we have demonstrated that multi-dose cardioplegia fails to afford any substantial additional protection when compared with single-dose cardioplegia. Under conditions of extended hypothermia there may even be a detrimental effect of multi-dose cardioplegia.
|Number of pages||5|
|Journal||Journal of Cardiovascular Surgery|
|Publication status||Published - 1993|
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine