[Determinants of contractile reserve in the infarction area. A quantitative study using dobutamine in contrast left ventriculography].
OBJECTIVE
The aim of this study was to relate the contractile reserve in infarction segments to the dysfunction at rest and to the residual coronary stenosis.


METHODS
The study group consisted of 95 patients with a first myocardial infarction. Contrast left ventricular at baseline and after dobutamine infusion at 7.5 microg/kg/min and coronary angiograms were performed. The centerline method was used to quantify the extent of dysfunction (percentage of chords with dysfunction in the territory of the infarction artery) and its maximum severity (maximum units of standard deviation [SD] below the normal wall motion reference). Reduction of dysfunction extent with dobutamine was measured.


RESULTS
On increasing baseline dysfunction severity, both the magnitude of the response to dobutamine ( 2 SD 3 SD 4 SD +/- 5 SD [n = 15] = 9+/-13%, > 5 SD [n = 13] = 3+/-4%, p = 0,0001), and the number of patients with a significant (> or =15%) positive response ( 2 SD 3 SD 4 SD 5 SD = 0%, p<0,0001) decreased. There were no differences in dobutamine improvement among the subgroups with (n = 84) or without (n = 11) significant stenosis in the infarction artery (18+/-15 vs. 16 +/-18%), or between the subgroups with a patent (n = 76, 18+/-19%) or occluded (n = 19, 11+/-11%) artery.


CONCLUSIONS
Dobutamine response is related to dysfunction severity in the infarction area: when the severity is 5 (high negative response prevalence), dobutamine testing does not seem indicate. The existence of residual coronary stenosis does not attenuate contractile reserve at low dobutamine doses.
Sanchis
J
J
Servicio de Cardiología, Hospital Clínico Universitario, Valencia.
Bodí
V
V
Berenguer
A
A
Insa
L
L
Mainar
L
L
Valls
A
A
Chorro
F J
FJ
Gómez-Aldaraví
R
R
López Merino
V
V
D002316:Cardiotonic Agents; D003327:Coronary Disease / Q000209:etiology / Q000503:physiopathology; D004280:Dobutamine; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D008875:Middle Aged; D009200:Myocardial Contraction; D009203:Myocardial Infarction / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D011859:Radiography; D012720:Severity of Illness Index
D002316:Cardiotonic Agents; D004280:Dobutamine