Electrocardiogram . It is the graphic recording of the changes of electrical potentials produced during the activity of the heart muscle and that are propagated by the tissues and organic liquids that surround the heart to the body surface. These bioelectric signals, once amplified, are picked up by metal devices called electrodes , which are placed on the limbs and anterior chest wall .
Summary
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- 1 Electrocardiography in Cuba
- 2 Utility
- 3 Examination procedure
- 4 Normal electrocardiogram
- 5 References
Electrocardiography in Cuba
The application of the rope galvanometer to record the electrical activity of the heart by Dr. Willen Eithoven and the completion in 1902 of the first electrocardiogram, improved the diagnosis of Cardiovascular Diseases . The electrocardiography is introduced into Cuba in 1919 , difficulties in marketing were the causes of his arrival to the country 17 years after the completion of the first. Initially it had a private use and 6 years later with its introduction in the Hospital “General Calixto García” its employment is socialized.
Dr. José Manuel Martínez Cañas was the pioneer of electrocardiography in Cuba; it has as merit also having introduced the phonocardiography , he was the author of the first scientific works on cardiology published in Cuba and founder of the specialty in the country. Another prominent Cuban doctor, Dr. Octavio Montoro y Saladrigas, was closely linked to the first uses of electrocardiography and was also a founder of cardiology.
Utility
The ECG is very useful in the clinic due to its easy availability and versatility, as well as its non-invasive nature. It is of relevant importance in the diagnosis of cardiac arrhythmias , conduction disorders and myocardial ischemia . Electrocardiography also recognizes inflammatory disorders of the heart and pericardium , cardiac enlargements (atrial and ventricular), electrolyte disorders due to excesses or defects ( potassium , calcium ), as well as the toxic effects of some drugs.and is capable of predicting possible sudden deaths. It is a complex subject, whose exact and thorough understanding requires a lot of study and knowledge about electrophysiology .
Examination procedure
The patient will be lying down. The doctor will clean several areas on the arms , legs, and chest, and then attach small patches called electrodes to these areas. It may be necessary to shave or grab some hair so that the electrodes stick to the skin . The number of patches used may vary. The patches are connected by cables to a machine that converts electrical signals from the heart into wavy lines, which are often printed on paper. The test results are reviewed by the doctor.
Patient applying an EKG
Typically, the patient needs to remain still during the procedure. The doctor may also ask you to hold your breath for a few seconds as the test is being done. Any movement, including muscle tremors such as shivering, can alter the results, so it is important to be relaxed and relatively warm during an ECG recording. Sometimes this test is done while exercising or under minimal stress to monitor changes in the heart. This type of ECG is often called a stress test.
The doctor should know about all the medications the patient is taking, as some may interfere with the test results. Exercising or drinking cold water immediately before the ECG can cause false results. An EKG is painless. No electricity is sent through the body. Electrodes may feel cold when first applied.
Normal electrocardiogram
A normal EKG is one that shows a regular rhythm and with a Heart Rate within the normal ranges (60-100 bpm). A normal electrocardiogram result indicates that the heart has no problems conducting its electrical impulses. However, there are cardiac abnormalities that are not reflected on an ECG. In these cases the doctor usually recommends complementing the study with an Echocardiogram or with a Holter.