Objectives.: This investigation studied the relation between regional myocardial blood flow and left ventricular function during dobutamine stress in patients with coronary artery disease. Background.: Dobutamine stress is becoming more frequently used as an alternative to dynamic exercise in patients with ischemic heart disease. Methods.: We studied 12 patients with coronary artery disease. Dobutamine was infused from 5 μg/kg body weight per min up to 40 μg/kg per min or until chest pain or other intolerable side effects. Regional myocardial blood flow was measured with positron emission tomography and oxygen-15-labeled water. Regional wall motion was assessed in three short-axis slices by magnetic resonance imaging. Each slice was subdivided into four regions: septal, anterior, lateral and inferior. A total of 140 regions were suitable for comparison. Results.: During stress, new wall motion abnormalities developed in 27 regions. Myocardial blood flow (mean ± SD) increased in 113 regions that did not develop wall motion abnormalities (0.98 ± 0.26 [baseline]vs. 1.98 ± 0.87 [dobutamine] ml/min per g, p <0.001), whereas it did not change significantly in regions with stress-induced wall motion abnormalities (1.00 ± 0.28 [baseline] vs. 1.30 ± 0.62 [dobutamine] ml/min per g, p = NS). An absolute decrease in myocardial blood flow below the value at rest was observed in seven segments that developed wall motion abnormalities during stress. Conclusions.: The normal functional response to dobutamine stress is paralleled by an increase in coronary flow, whereas mechanical dysfunction is accompanied by a blunted increase, or even a paradoxic decrease, in regional coronary flow.
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine