Left atrial functional reserve in patients with nonischemic dilated cardiomyopathy: an echocardiographic dobutamine study.
OBJECTIVE
To evaluate left atrial functional reserve in patients with chronic heart failure and nonischemic dilated cardiomyopathy (DCM).


BACKGROUND
Left ventricular functional status has been investigated using echocardiographic dobutamine.


METHODS
In 35 consecutive patients (29 men and 6 women; mean +/- SD age, 42.37 +/- 13.5 years), peak oxygen consumption (O(2)max) was measured; the day after, a low-dose dobutamine (5 to 10 micro g/kg/min, of 5 min each step) study was performed. Left atrial volumes at mitral valve opening, onset of left atrial systole, and mitral valve closure were measured by using two-dimensional echocardiography. Left atrial active emptying volume (LAEV) [volume at onset of atrial systole - minimal volume] was calculated, as was left atrial active emptying fraction (LAEF): [(volume at onset of atrial systole - minimal volume)/volume at onset of atrial systole] x 100. The changes (values obtained after inotropic stimulation minus those obtained at baseline) of the above-mentioned echocardiographic variables were considered as left atrial functional reserve.


RESULTS
In the entire study group after dobutamine infusion, increases in LAEV (3.34 +/- 7.54 mL, p = 0.01) and LAEF (6 +/- 13.2%, p = 0.01) were observed. The changes in the above-mentioned parameters were correlated with O(2)max values (r = 0.73 and r = 0.71, respectively; p < 0.001). After inotropic stimulation, LAEV and LAEF were increased in patients with O(2)max values > 14 mL/kg/min (5.62 +/- 7.28 mL and 10.04 +/- 13.13%, respectively) and decreased in patients with O(2)max values < 14 mL/kg/min (- 1.08 +/- 6.13 mL and - 1.6 +/- 9.9%, respectively; p = 0.01 for both).


CONCLUSIONS
Echocardiographic dobutamine can evaluate left atrial functional reserve in patients with nonischemic DCM.
Paraskevaidis
Ioannis A
IA
Second Department of Cardiology, Onassis Cardiac Surgery Center, 356 Syngrou Avenue, 176 74 Athens, Greece. elbee@ath.forthnet.gr
Dodouras
Thomas
T
Adamopoulos
Stamatis
S
Kremastinos
Dimitrios Th
DT
D000328:Adult; D002311:Cardiomyopathy, Dilated / Q000000981:diagnostic imaging* / Q000473:pathology; D016022:Case-Control Studies; D004280:Dobutamine; D015150:Echocardiography, Doppler / Q000379:methods*; D005080:Exercise Test; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011336:Probability; D011379:Prognosis; D011446:Prospective Studies; D012016:Reference Values; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013318:Stroke Volume / Q000502:physiology*; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging*; D016277:Ventricular Function, Left / Q000502:physiology
D004280:Dobutamine