Abstract:
Low-dose dobutamine stress echocardiography (LDDSE) is one of the methods most used to
assess myocardial viability. Glucose-insulin-potassium (GIK) has been shown to increase
contraction of the ischemic zone. The aim of this study was to compare LDDSE and echocardiography
during GIK infusion for detection of myocardial viability in patients with chronic
coronary artery disease (CAD) and myocardial dysfunction. Twenty-one patients who had
chronic CAD and myocardial dysfunction were included in the study. Glucose-insulin-potassium
protocol consisted of a fixed dose of insulin (100 μU/kg/hour IV) and a variable
glucose/potassium infusion rate. GIK echocardiography was made at baseline and after 60
minutes of GIK infusion. During continuous electrocardiographic, blood pressure, and echocardiographic
monitoring, an intravenous infusion of dobutamine (3 μg/kg body weight/min) was
started with an infusion pump and continued for 5 minutes and then increased to 5 μg/kg/min
and 10 μg/kg/min for another 5 minutes. The detected viable myocardium was defined as 1 or
2 scores decreasing in at least 2 adjacent abnormal segments during LDDSE and GIK echocardiography.
Viability was detected in 19% (52 segments) of the asynergic segments at baseline
with GIK echocardiography and 16% (44 segments) of those segments with LDDSE (p > 0.05).
Left ventricular wall motion score index at baseline was 2.24 ±0.35 and it decreased significantly
during both LDDSE (p = 0.004 vs 2.11 ±0.36) and GIK echocardiography (p=0.001 vs
2.09 ±0.32). The agreement between LDDSE and GIK echocardiography for detection of
myocardial viability was 95%. This study shows that GIK echocardiography is similar to LDDSE
for detection of myocardial viability. With the support of further clinical studies GIK echocardiography
can be used to detect myocardial viability in patients with chronic CAD.
