Glucose-insulin-potassium solution improves left ventricular mechanics in diabetes.
BACKGROUND
The mechanism by which glucose-insulin-potassium solutions enhance recovery of left ventricular function after myocardial ischemia in diabetic patients is not well understood. We evaluated the effect of glucose-insulin-potassium on ventriculoarterial coupling and left ventricular mechanics in a chronic ovine model of diabetes.


METHODS
Diabetes was induced in 6 sheep with streptozotocin. After 6 months of diabetes, the response of the left ventricular pressure-volume relationship to 60 minutes of intravenous glucose-insulin-potassium solution (1,000 mL of 5% dextrose in water, 100 IU of regular insulin, 90 mmol of KCl at 1.5 mL x kg(-1) x h(-1)) was determined.


RESULTS
Glucose-insulin-potassium solution increased end-systolic elastance 68% (p = 0.01) and improved ventriculoarterial coupling (1.7+/-0.3 to 1.0+/-0.1; p < 0.01). Potential energy decreased 35% (p = 0.01), and pressure-volume area decreased 20% (p = 0.01). However, stroke work did not change; therefore stroke work efficiency increased from 50.1%+/-3.5% to 60.2%+/-5.1% (p = 0.01).


CONCLUSIONS
Glucose-insulin-potassium solution improves left ventricular contractility and ventriculoarterial coupling in diabetes. Left ventricular mechanics is improved by decreasing total mechanical work without significantly affecting stroke work, resulting in improved stroke work efficiency. Improved efficiency facilitates understanding of the enhanced tolerance to myocardial ischemia afforded by glucose-insulin-potassium solution.
Ramanathan
Tharumenthiran
T
Cardiac Technology Centre, Department of Cardiology, Royal North Shore Hospital, Sydney, NSW, Australia. indranrama@yahoo.com
Shirota
Kazuaki
K
Morita
Shin
S
Nishimura
Takashi
T
Huang
Yifei
Y
Hunyor
Stephen N
SN
D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000503:physiopathology*; D005947:Glucose / Q000494:pharmacology*; D007262:Infusions, Intravenous; D007328:Insulin / Q000494:pharmacology*; D009200:Myocardial Contraction / Q000187:drug effects / Q000502:physiology; D011188:Potassium / Q000494:pharmacology*; D012756:Sheep; D013318:Stroke Volume / Q000187:drug effects / Q000502:physiology; D016277:Ventricular Function, Left / Q000187:drug effects* / Q000502:physiology
D007328:Insulin; C030396:glucose-insulin-potassium cardioplegic solution; D005947:Glucose; D011188:Potassium