Serial changes in response of hibernating myocardium to inotropic stimulation after revascularization: a dobutamine echocardiographic study.
OBJECTIVE
We sought to evaluate the serial changes in the response of the hibernating myocardium to dobutamine stimulation after revascularization.


BACKGROUND
An improvement in myocardial contraction during dobutamine stress echocardiography (DSE), particularly a biphasic response, predicts recovery of rest function. However, little is known about the changes in the response of the myocardium to dobutamine after revascularization.


METHODS
Thirty-four patients with stable coronary artery disease and regional left ventricular dysfunction underwent DSE before, early (within 1 week) and late (>6 weeks) after coronary angioplasty. Dobutamine was given in incremental doses from 2.5 to 40 microg/kg body weight per min.


RESULTS
Of 180 revascularized segments with severe rest dysfunction, recovery of rest function was seen in 56 segments (31%) late after angioplasty, 80% of which had early recovery. Ventricular function during DSE was similar early and late after revascularization. Patients who showed a biphasic response to DSE before revascularization (n = 12) had the most improvement in function at rest (mean [+/-SD] wall motion score index [WMSI] 1.98 +/- 0.75 vs. 1.35 +/- 0.54, p < 0.05) and during DSE (2.11 +/- 0.67 vs. 1.21 +/- 0.41, p < 0.05) late after revascularization. Patients with sustained improvement during DSE before revascularization had no significant change in wall motion during DSE after angioplasty. However, patients without improvement in function at low dose DSE, who demonstrated worsening of function at a high dose, had significant augmentation in wall motion during DSE after revascularization (WMSI 2.16 +/- 0.50 vs. 1.60 +/- 0.57, p < 0.05). Patients who had no recovery of rest function had significant improvement in wall motion response to DSE, particularly when ischemia was inducible before revascularization.


CONCLUSIONS
In myocardial hibernation, the majority of recovery of rest function occurs early after revascularization. Although patients who recover rest function show the most marked improvement in wall motion during DSE, those without recovery of rest function also have improved function during DSE, particularly when there is evidence of ischemia before revascularization.
Afridi
I
I
Department of Medicine, Baylor College of Medicine and The Methodist Hospital Echocardiography Laboratory, Houston 77030, USA.
Qureshi
U
U
Kopelen
H A
HA
Winters
W L
WL
Zoghbi
W A
WA
D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D002316:Cardiotonic Agents / Q000494:pharmacology*; D017023:Coronary Angiography; D003327:Coronary Disease / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000628:therapy; D004280:Dobutamine / Q000494:pharmacology*; D004452:Echocardiography; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000187:drug effects*; D017682:Myocardial Stunning / Q000000981:diagnostic imaging / Q000503:physiopathology*; D011446:Prospective Studies; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology*
D002316:Cardiotonic Agents; D004280:Dobutamine