What kind of information does a physician receive from an EKG, and how is an EKG made? The EKG is a routine procedure which is frequently used, the results of which can be partially evaluated by a computer, but are often overestimated. Sometimes patients fear the EKG because they are under the false impression that electrical currents are sent through their bodies. What really happens?
Each heart beat produces a very weak electrical current of .001 volts. Highly sensitive instruments can measure these currents in the arms, legs, and chest by amplifying the signals and then measuring them. It is even possible to make EKG's without using any wires connecting to the patient.
Abnormal waves often indicate impaired circulation of the heart muscle resulting from, for example, coronary arteriosclerosis or a heart attack. It is also feasible to detect an abnormal rhythm. Unfortunately, it is not possible to state with absolute certainty
from a normal EKG that a heart is healthy. In fifty percent of coronary patients, the EKG at rest does not show significant abnormality!
For this reason, the physician will also order an exercise EKG if he suspects coronary heart disease. This EKG is made while the patient walks on a treadmill or sits pushing the peddles of an
exercise bicycle. Depending upon the peddle resistance, the patient can achieve twenty-five, fifty, seventy-five or a hundred watts of work energy. At the same time the pulse rate and blood pressure are monitored. Following the procedure of exercise, the recuperation capacity is evaluated as the body returns to the resting state. The EKG may also be observed by a wireless (telemetric) EKG during an exercise therapy session as in the course of rehabilitation from, a heart attack. Recently an EKG has
been developed in the form of a small box which the patient carries for a twenty-four hour period. In this manner, abnormal and possibly dangerous aberrations of the heart rhythm can be detected if it is suspected that a certain daily activity causes problems for the patient.
Bicycle ergometry or treadmill EKG's can be very useful. Impaired circulation of the myocardium, the effect of medication, as well as abnormal rhythm not discoverable by a resting EKG can thus be detected and treated in an early stage. Moreover, bicycle ergometry can be used for training in the rehabilitation after a heart attack.
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Cardio & Blood
