Is Dobutamine Stress Echocardiography Useful for Noninvasive Differentiation of Ischemic from Idiopathic Dilated Cardiomyopathy?

Dobutamine stress echocardiography was performed in 56 consecutive patients, mean age: sixty-two ±twelve years. Twenty-two patients had an idiopathic dilated cardiomy-opathy (group 1) and 34 had angiographically proven ischemic dilated cardiomyopathy (group 2). Wall motion score index and left ventricular ejection fraction were determined at baseline, 5 μg/kg/min, peak, and ten minutes after stepwise dobutamine infusion. Worsening or no change in global wall motion score was observed in 9 group 2 patients (26%) and 1 group 1 patient (5%, P=.07). No significant difference was observed with regard to wall motion score index decrease between baseline and peak dose. Left ventric-ular ejection fraction increase during dobutamine infusion was comparable in both groups. Thus, an ischemic response was observed more often in the coronary artery disease group, yielding a good specificity and positive predictive value although sensi-tivity was low. However, left ventricular function improvement did not help to discrimi-nate patients with or without significant CAD