Ventricular arrhythmias occur in the lower chambers of the heart, called the ventricles. Supraventricular arrhythmias occur in the area above the ventricles, usually in the upper chambers of the heart, called the atria.
The irregular beats can either be too slow bradycardia or too fast tachycardia. Bradycardia is a very slow heart rate of less than 60 beats per minute.
Bradycardia most often affects elderly people, but it may affect even the very young. It may be caused by one of two sources: The central nervous system does not signal that the heart needs to pump more, or the SA node may be damaged. This damage might be related to heart disease, aging, inherited or congenital defects, or it might be caused by certain medicines—including those used to control arrhythmias and high blood pressure.
Tachycardia is a very fast heart rate of more than beats per minute. The many forms of tachycardia depend on where the fast heart rate begins. If it begins in the ventricles, it is called ventricular tachycardia. If it begins above the ventricles, it is called supraventricular tachycardia.
Ventricular tachycardia is a condition in which the SA node no longer controls the beating of the ventricles. Instead, other areas along the lower electrical pathway take over the pacemaking role. Since the new signal does not move through your heart muscle along the regular route, the heart muscle does not beat normally. The most serious arrhythmia is ventricular fibrillation, which is an uncontrolled, irregular beat. Instead of one misplaced beat from the ventricles, you may have several impulses that begin at the same time from different locations—all telling the heart to beat.
The result is a much faster, chaotic heartbeat that sometimes reaches beats a minute. This chaotic heartbeat means very little blood is pumped from the heart to the brain and body and can result in fainting. Medical attention is needed right away. About , deaths from heart attacks each year are thought to be caused by ventricular fibrillation.
People who have heart disease or a history of heart attack have the highest risk of ventricular fibrillation. Forgot Username? About MyAccess If your institution subscribes to this resource, and you don't have a MyAccess Profile, please contact your library's reference desk for information on how to gain access to this resource from off-campus.
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Enable Autosuggest. You have successfully created a MyAccess Profile for alertsuccessName. Previous Chapter. Next Chapter. Bashore T. Bashore, Thomas M. When the heart rate is less than 60 beats per minute that condition is termed as bradycardia.
This is the basic difference between tachycardia and bradycardia. Different clinical conditions can result in these abnormalities of the heart rate. Therefore, the correct identification of the underlying pathology and the proper treatment of it are the key to getting rid of them. You can download PDF version of this article and use it for offline purposes as per citation notes. Hall, John E. Guyton and Hall textbook of medical physiology. Philadelphia, PA: Elsevier, Ranidu is passionate about writing articles on medical topics in general parlance.
His experience in communicating with the general public during his medical practice has enabled him to describe facts that a layman has to know about a particular disorder in a concise and understandable manner. Your email address will not be published. Figure ECG showing Bradycardia. Leave a Reply Cancel reply Your email address will not be published. Tachycardia vs Bradycardia.
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