DIAGNOSTIC INSTRUMENTS AND MACHINES USED FOR THE DETECTION OF
CARDIAC PATHOLOGIES AND ABNORMALITIES
The use of exciting, new, and increasingly sophisticated techniques for diagnosis of heart disorders has burgeoned in recent years. The United States ranks among the world leaders, with remarkable availability of these procedures for patients (30:273). The tests are used not only to diagnose, but also to pinpoint exact locality, extent, and severity of the abnormality, as well as to check the efficacy of treatment and the progress of the disease.
The danger of this mushrooming technology is the possible overuse of tests. It is emphasized that in most cases one or at most two tests are required to gain enough information (31:116). The cornerstones in cardiology are still the taking of accurate history and thorough physical examination. These alone will yield an accurate diagnosis in many if not the majority of cases. In fact, the overuse of modern techniques which may be inadequately interpreted has been linked with poor clinical judgment and management (9:189). In general, diagnosis follows a stepwise progress starting with the simplest, least invasive, least expensive, and least risky methods. With this knowledge, appropriate decisions can be made regarding the use of more sophisticated and/or invasive procedures.
The stethoscope and sphygmomanometer (blood pressure monitor) are the two basic instruments at the start of this diagnostic progression, and they form part of the physical examination. Detection of auscultation (sound waves that travel through the body) of the heart depends on the vibrations set up by the sudden acceleration and deceleration of the blood as it is controlled by the intracardiac valves in the beating heart (7:233). The stethoscope does not amplify the sound but channels it to the ears of the examiner, who uses the bell-type endpiece for low frequency sounds and the wide, flat diaphra...