Title of article :
Effect of β-adrenergic receptor blockade on the physiologic response to dobutamine stress echocardiography
Author/Authors :
Neil J. Weissman، نويسنده , , Michael W. Levangie، نويسنده , , John B. Newell، نويسنده , , J. Luis Guerrero، نويسنده , , Arthur E. Weyman، نويسنده , , Michael H. Picard، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 1995
Pages :
6
From page :
248
To page :
253
Abstract :
Dobutamine is an effective pharmacologic stress agent because of its β-adrenergic receptor agonist properties. Theoretically, concurrent β-adrenergic receptor blockade might alter this effectiveness, but clinical experience has been variable. Before assessing the relative effectiveness and implications of dobutamine stress echocardiography (DSE) to detect myocardial ischemia in the presence of β-blockade the physiologic and hemodynamic effects of dobutamine with simultaneous β-blockade must be understood in a controlled setting. Therefore the purpose of this study was to determine if β-blocking agents alter the timing and magnitude of the physiologic response to graded doses of dobutamine during a standard DSE. Paired DSEs were performed in seven instrumented open-chest dogs with and without β-blockade (esmolol 500 μ/kg initial bolus and 100 μ/kg/min infusion). Heart rate, systolic pressure, proximal left anterior descending coronary artery flow, myocardial thickening, and percentage left ventricular area change (%AC) were monitored. The data for each parameter were fit to linear or exponential functions. With graded doses of dobutamine, the rate of increase in coronary flow was greater than that in %AC, which in turn was greater than that in heart rate (p < 0.05). With the addition of β-blockade, (1) despite attainment of a higher peak dobutamine dosage (14.6 ± 8.2 vs 38.6 ± 3.8 μ/kg/min; p < 0.005), the peak heart rate, coronary flow, and %AC were lower (p < 0.01); (2) the rates of increase in heart rate, flow, and %AC were blunted compared with pre-β-blockade responses (p < 0.05); and (3) the rates of increase in heart rate and flow were less than that in %AC (p = 0.03). Regardless of β-blockade, mean systolic blood pressure remained relatively unchanged from predobutamine levels. β-Blocking agents alter the magnitude and timing of the physiologic response during DSE in this canine model. By lowering the peak cardiac workload and inotropic response during DSE, β-blockade has the potential to influence the sensitivity of this test.
Journal title :
American Heart Journal
Serial Year :
1995
Journal title :
American Heart Journal
Record number :
526607
Link To Document :
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