According to Practical Clinical Skills, reading a telemetry strip, or an electrocardiogram, begins with understanding the events that a normal electrocardiogram tracing represents. Once a person has a good grasp of this concept, it is possible to move on to interpreting the heart rate and rhythm and detecting abnormalities. However, it takes time and a good deal of practice to perfect the technique.Know More
Practical Clinical Skills explains that a normal EKG tracing represents the waveforms created by the electrical activity of the heart muscle as it beats one time. It begins with the "P" wave, which is normally deflected upward and represents atrial depolarization, the electrical event that initiates the beat. The "P" wave is followed by the QRS complex, which represents the depolarization and contraction of the left ventricle or the actual pumping action of the heart. It begins with the "Q" wave, which deflects downward and is followed by a large upward deflection, the "R" wave. The "R" wave is then followed by a larger downward deflection, the "S" wave and a small upward-deflected "T" wave, which represents repolarization or the heart's return to a resting state.
In some tracings, a last wave, known as the "U" wave, may be visible. This represents the recovery of specialized fibers within the heart muscle, known as the Purkinje fibers, which are responsible for synchronizing the heartbeat. The intervals between the various waveforms, their shape and their size are important indicators of how the heart muscle is functioning and a person's overall health, according to Practical Clinical Skills.Learn More
A TB skin test is read between 48 and 72 hours after administering the injection by measuring the size of any swelling found at the site of the test. If little or no swelling is present, the test is negative, according to the Centers for Disease Control.Full Answer >
WebMD explains that to measure blood pressure at home, the proper equipment is needed. Home blood pressure monitors are available in the traditional arm-cuff model and in a wrist model.Full Answer >
The cancer antigen 125 test returns a false positive if medical personnel administer it at certain times during the menstrual cycle. Pelvic inflammatory disease, liver disease, pregnancy, lupus or endometriosis can also cause a false positive, according to WebMD.Full Answer >
Liver function tests often involve many different measurements that can often be hard to understand. The main values measured in a liver blood test are the aminotransferases (ALT and AST), each accompanied with a range that is considered normal, states eMedicineHealth.Full Answer >