Enhanced ventricular recovery from high dose glucose, insulin and potassium with cardiopulmonary bypass support prior to cardioplegic arrest.

The concept that a beneficial preconditioning effect in ventricular recovery exists using high dose glucose (0.5 mg/kg), insulin (0.3 unit/kg), and potassium (0.2 mmol/kg) (GIK) with 20 min of normothermic cardiopulmonary bypass support (CPB) prior to 60 min of cardioplegic arrest (CA) was tested using 32 mongrel dogs divided into four subset test groups. Group 1 was given GIK and 20 min of CPB prior to CA, Group 2 was given GIK systemically over 10 min but no CPB prior to CA, Group 3 underwent 20 min of CPB without GIK and Group 4 was the control group with no GIK and no CPB assist. To focus specifically on in vivo ventricular recovery, dP/dT (mmHg/sec), developed pressure (dP) (mmHg), and segmental shortening (SS) (%) were measured prior to CPB, then 15, 30, 60, and 90 min after weaning from CPB, while left atrial pressure was kept constant. The average dP/dT (% recovery) at 60 min in Group 1 was 1,454 (122%) and significantly higher (P < or = 0.05) than Groups 2: 1,189 (99%), 3: 1,027 (79%) and 4: 1,030 (82%). Developed pressure at 90 min (% recovery) in Group 1, 88 (111%) was also better than Groups 3, 74 (86%), and 4, 72 (87%) (P < or = 0.05). Segmental shortening (% recovery) at 30 min was better in Group 1 (94%) than in Groups 2 (59%), 3 (73%) and 4 (68%). We conclude that GIK added to 20 min of CPB support prior to cardioplegic arrest enhances post CPB ventricular recovery and weaning from CPB.