![]() It has even been suggested 2 that we should dispense with the ECG when stress echocardiography is performed. Some authors 1,2 have compared the ECG and imaging information for the same patient using pharmacological stress testing with dobutamine and conclude that imaging is more trustworthy and informative, and that its precision for detecting ischemia is greater than that of ECG. On the contrary, if the image is normal and ECG changes are suggestive of ischemia, the patient is usually considered an electrocardiographic false positive. When imaging shows ischemia, although there are no exercise-induced changes in the electrocardiogram (ECG), the patient is considered to have ischemia. Something similar occurs when effort stress testing is accompanied by imaging. When pharmacological stress testing is performed with imaging, the electrocardiographic information can usually be overlooked and the image is used fundamentally to determine if a test is positive or negative. Generally, inotropic or chronotropic-positive drugs are used with echocardiographic imaging and arteriolar vasodilators are used with radionuclide perfusion scans, although any type of drug can be used with any imaging system. Two groups of drugs are used in pharmacological stress tests: inotropic or chronotropic-positive drugs and arteriolar vasodilators. Pharmacological stress for the diagnosis of ischemic heart disease is indicated only in patients incapable of physical exercise, since the drugs do not reproduce a physiological situation, so many data of interest provided by the effort stress test cannot be evaluated. ![]() The capacity to tolerate effort testing indicates, in general, a better prognosis than inability to tolerate it. This technique is widely available, inexpensive, easy to perform, and contributes different types of information: functional capacity, chronotropic response and the response of blood pressure to exercise, appearance of arrhythmias or conduction disorders, lower-limb claudication, chest pain, and electrocardiographic changes suggestive of myocardial ischemia. Of all the noninvasive tests for inducing and detecting myocardial ischemia, the most elemental is exercise stress testing. For this reason, we usually resort first to noninvasive tests for the diagnosis of ischemic heart disease. If we did so, we would be absolutely sure of the presence or absence of obstructive injuries of the epicardial vessels, but the cost-benefit relation would be inadequate, and there probably would not be enough hemodynamic units available. It would be an error to perform coronary arteriography in every patient with chest pain. Nevertheless, it is not possible or suitable to use these methods indiscriminately in all patients. The instruments available in tertiary hospitals allow us to exclude or diagnose any heart disease with a high degree of precision.
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