conditions is then compared with imaging obtained after coronary vasodilation. Patients are also queried regarding adverse side effects, which may include light-headedness, chest pain or pressure, and nausea. Echocardiographic images (in contrast to perfusion images are made during dobutamine infusions. In some cases, like exercise stress tests, pharmacologic studies may be prematurely terminated due to the development of worsening symptoms or significant heart rhythm irregularities.
QUESTION: Can the results of these tests be used to develop an exercise prescription? ANSWER: It is difficult to use the results of these tests to develop an exercise prescription. This is primarily because the rises in heart rate and oxygen consumption during pharmacologic testing are far lower than those achieved with exercise stress. These tests simply suggest whether there is underlying myocardial is chemia and coronary artery disease. Consequently, for patients who have recently undergone pharmacologic stress testing, many clinicians recommend an initial exercise heart rate that is 20 y to 30 beats above standing rest as the prescribed training intensity, using perceived exertion as an ad- junctive intensity modulator.