I enjoyed reviewing what EKG's can measure and what the waves represent. It is always good to refresh your memory so when patients ask you why you are performing the test and what problems can be be assessed from the test, we will have good and clear informative explanations.
An electrocardiogram is simply a recording of the electrical activity of your heart. By interpreting an ECG tracing, your doctor can diagnose several abnormal conditions that can affect your heart. Some of these conditions include: rhythm disturbances, a heart attack, or other abnormalities of the heart's structure. Two rhythm abnormalities include: tachycardia, which is an elevated resting heart rate and bradycardia, which is a resting heart rate under 50 beats a minute. Adult heart rates are normally about 75 beats per minute.
Transmission of action potentials through the conduction system generates electric currents that can be detected by electrodes placed on the body's surface. The ECG is a composite of all the action potentials, graphed as a series of up and down waves, produced by cardiac muscle fibers during each heartbeat. The electrocardiograph amplifies the heart's electrical signals and produces 12 different tracings from different combinations of limb and chest leads.
It has been about 9 years since I got certified as an EKG technician. I am now a Medical Assistant and I perform EKG's everyday at work. I realized in class that I had forgotten what parts of the wave represents. I learned that the P wave, is a small upward deflection on the ECG. It represents atrial depolarization. A fraction of a second after the P wave begins, the atria contract. The second wave, called the QRS complex, begins as a downward deflection. The QRS complex represents the onset of ventricular depolarization as the cardiac action potential spreads through ventricular contractile fibers. Shortly after the QRS complex begins, the ventricles start to contract. The third wave is a dome shaped upward deflection called the T wave. It indicates ventricular repolarization and occurs just before the ventricles start to relax. Repolarization (relaxation) of the atria is not usually evident in an ECG because it is masked by the larger QRS complex.
The simplest piece of information the ECG can provide is the rate of your heartbeat at the time you had this test. If 10 QRS complexes are recorded on the ECG paper or monitor in 10 seconds, then your heart rate is 60 beats per minute. The ECG can distinguish normal sinus rhythm from all types of tachycardia and bradycardia rhythms.
The ECG can also tell a physician if a heart attack has happened in the past. An elevated portion between the QRS complex and the T wave will show a strong indication that heart muscle injury, such as a heart attack, is occurring. If there is a deep early portion of the QRS complex, this may be evidence that a heart attack may have happened in the past.
Even if your not a doctor, I feel it is important to know how to look for this if you are the person performing the EKG. When I was only 19 and doing one of the morning rounds of EKG's for patients staying in the hospital, I noticed that there was a large rounded portion after the QRS wave. The patient was an elderly man and was sleeping. Instead of bringing the EKG down to my department to be viewed later by the cardiologist that comes in the afternoon, I brought it to one of the physicians on the floors. Indeed the patient was having a heart attack. I was thankful that I trusted my gut, to show it to someone and was thankful that I had learned what to look for in an EKG.
Clarissa Larry
ReplyDelete4/27/09
I found this blog on Electrocardiography to be very interesting.
I envy that you have already had the hands on with this equipment, and that you understood what Dana was discussing in lecture that night.
I understood what Dana was saying, however it was all new information and it just looked like wavy lines to me.
I wish I had known what to look for years ago. I lost a grandfather to heart problems, and when my husband was 38 , he had a heart attack that required him to have a stint.
Watching the heart monitor and when they were doing the ECG was so foreign to me at the time.
I now feel more confident when going to the doctors or for procedures to ask questions.
Great job Toby on going with your gut and reporting to the physician on the floor your concerns about the gentleman’s EKG.
You are going to make a great nurse!!!
Thank you Clarissa for your comments :)
ReplyDeleteIt is nice when we can put our knowlege and what we learn in school into the real world.
You will make a great nurse as well ! :)
My neighbor recently had a heart attach, His daughter performed CPR and saved his life. this happened 5 months ago and he is still out of work. His doctor will not let him return to work until his breathing improves. I was wondering if the heart attach would still be noticable after rehabilitation and time? I realize the muscle cells do not regenerate but could the other become strong enough to make it unnoticable on the ECG?
ReplyDeleteMy husband had a heart attack. He had what they call an acute inferior mi. Acute just means it was happening at the time, inferior is the location of the vessels, which is below, MI just means heart attack. The blood clot was in the inferior part of this heart but his biggest clot was at the proximal part of his RCA. When you see the elevation on the EKG you immediatly know he is what they medical field call a STEMI. St evelated mi. We like to call it at the hospital tombstone. Hardly anyone that is stistaining a heart attack to the level he was usually lives, they are usually making plans for a
ReplyDelete"tombstone". Some say it looks like a fireman's hat. I am grateful because I knew all the staff including the cardiologist so I knew what to expect when they told me the news. My husband was only 39 years old. We had celebrated his birthday just 5 days prior. It has been a year and a half and I still cry. Ironic really, I knew what to expect, I had a feeling this would happen because of all the stress he had and I still get choked up. It's hard being on the other side with a patient. I know for me it has taught me a lot about how to help families. When I talk to them I myself can be empathetic, you can't do that unless you have lived it. It has helped.