Postextrasystolic potentiation and dobutamine echocardiography in predicting recovery of myocardial function after coronary bypass revascularization.
BACKGROUND
Identification of viable but hibernating myocardium remains a relevant issue in the current era of myocardial revascularization. Echocardiography can be helpful in detecting reversible contractile dysfunction and optimizing the selection of patients for coronary bypass surgery.


RESULTS
Eighty-four consecutive candidates for bypass surgery with chronic multivessel coronary artery disease were screened, and 60 were included in this prospective study. Preoperative evaluation of a reversible contractile dysfunction in asynergic myocardial regions was performed by dobutamine infusion at 5 (low dose) and 10 (intermediate dose) microg x kg(-1) x min(-1) with each stage lasting at least 5 minutes; postextrasystolic potentiation (PESP), with a coupling interval ranging from 500 to 300 ms with a progressive 10-ms decrease; or a combination of both dobutamine infusion and PESP. Sensitivity (92% versus 86%) and predictive accuracy (89% versus 84%) were higher with PESP than dobutamine (P=.009 and P=.001, respectively), but the combination did not improve sensitivity or accuracy. Dobutamine induced ischemic dysfunction in 15% of patients at the intermediate dose; however, the low dose resulted in loss of sensitivity.


CONCLUSIONS
PESP echocardiography is a useful and cost-effective method to identify viable myocardium in patients with multivessel coronary disease undergoing revascularization and is more sensitive and accurate than dobutamine infusion.
Scognamiglio
R
R
Department of Clinical and Experimental Medicine, University of Padua, Italy.
Fasoli
G
G
Casarotto
D
D
Miorelli
M
M
Nistri
S
S
Palisi
M
M
Marin
M
M
Dalla Volta
S
S
D000328:Adult; D000368:Aged; D005117:Cardiac Complexes, Premature / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D002316:Cardiotonic Agents; D001026:Coronary Artery Bypass; D004280:Dobutamine; D004452:Echocardiography; D005260:Female; D005500:Follow-Up Studies; D005544:Forecasting; D006321:Heart / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D011184:Postoperative Period; D011446:Prospective Studies; D016896:Treatment Outcome
D002316:Cardiotonic Agents; D004280:Dobutamine