Early systolic mitral annular motion velocities responses to dobutamine infusion predict myocardial viability in patients with previous myocardial infarction.
OBJECTIVE
This study was undertaken for the determination of the correlation between myocardial viability and regional systolic mitral annular motion velocity (MAV) response to dobutamine stress in patients with previous myocardial infarction (MI) with pulsed tissue Doppler scan imaging.


METHODS
The study included 45 patients (mean age, 65 +/- 12 years) with previous MI with 1 major coronary lesion and 30 healthy individuals (mean age, 61 +/- 14 years). 99mTc-methoxyisobutylisonitrile scintigraphy was performed to divide the patients into 2 groups: the viability (+) group (n = 25) and the viability (-) group (n = 20). Dobutamine was infused (at 2, 5, 10, and 20 microg/kg/min), and the peak first and second systolic MAVs (Sw1 and Sw2, respectively) were measured at the level of the mitral annulus corresponding to the infarct regions in the MI group and to the 6 mitral annular sites in the control group. In addition, the left ventricular wall motion score index (WMSI) was determined with 2-dimensional echocardiography.


RESULTS
At baseline, the WMSI was significantly greater and the mean Sw1 and Sw2 were significantly lower in both the viability (+) and (-) groups than in the control group, but there were no significant differences between the viability (+) and (-) groups. After dobutamine infusion, the WMSI improved only in the viability (+) group. The mean Sw1 and Sw2 increased significantly with 2 microg/kg/min and 5 microg/kg/min of dobutamine, respectively, in the viability (+) group. With an increase in Sw1 of 2.0 cm/s or more with 5 microg/kg/min of dobutamine, viable myocardium was detected, with a sensitivity of 92% and a specificity of 90%. There were no significant increases in Sw1 or Sw2 in the viability (-) group with dobutamine infusion.


CONCLUSIONS
Viable left ventricular myocardium is identified with peak early systolic MAV during dobutamine infusion.
Matsuoka
Masako
M
Second Department of Internal Medicine, School of Medicine, The University of Tokushima, Tokushima, Japan.
Oki
Takashi
T
Mishiro
Yuichiro
Y
Yamada
Hirotsugu
H
Tabata
Tomotsugu
T
Wakatsuki
Tetsuzo
T
Ito
Susumu
S
D000368:Aged; D006328:Cardiac Catheterization; D002316:Cardiotonic Agents; D016022:Case-Control Studies; D004280:Dobutamine; D025401:Echocardiography, Stress; D005260:Female; D006801:Humans; D008297:Male; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000187:drug effects / Q000502:physiology*; D009200:Myocardial Contraction / Q000187:drug effects / Q000502:physiology; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D019275:Radiopharmaceuticals; D013318:Stroke Volume / Q000187:drug effects / Q000502:physiology; D013599:Systole / Q000187:drug effects / Q000502:physiology; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods; D016277:Ventricular Function, Left / Q000187:drug effects / Q000502:physiology
D002316:Cardiotonic Agents; D019275:Radiopharmaceuticals; D004280:Dobutamine; D017256:Technetium Tc 99m Sestamibi