Cardiac Arrhythmias by Claire Perry 2 | CPR St. Louis

Atrial fibrillation is a fast and chaotic beating of the atria.  It mainly affects older people so the risk of developing atrial fibrillation dramatically increases past the age of sixty.  Atrial fibrillation, or A-fib as it is commonly referred to, is mostly caused by wear and tear on the heart, especially for those people with chronic high blood pressure or other heart problems.  During A-fib, the electrical impulse that causes the heart to beat becomes uncoordinated. The atria beat so fast, that instead of a single, forceful contraction, the atria of the heart twitch or fibrillate.  Atrial fibrillation can be very dangerous over time if left untreated and can even cause more serious conditions such as heart attacks, stroke, and death.


Cardioversion is often a treatment for A-fib.  A cardioversion is where an electrical shock is used to reset the heart to its regular rhythm.  Usually, this procedure is done in a hospital or doctor’s office, and the patient is given medication to relax during the duration of the procedure so there’s no pain involved. There are also anti-arrhythmic drugs available, although these medications do not cure the arrhythmia, they can reduce the episodes of tachycardia or slow down the heart when an episode does occur.  Some medications can slow down the heart so much that a pacemaker is necessary to regulate the electrical impulses sent throughout the heart.  Another arrhythmia that is very similar to A-fib is called atrial flutter.  The heartbeats in atrial flutter are more organized and more rhythmic than the electrical impulses involved with atrial fibrillation.  Atrial flutter can be life-threatening because the heart does not pump blood well when it is beating too fast.  When blood flow is diminished, vital organs, such as the heart and brain, may not get enough oxygen from the blood and begin to shut down resulting in major organ failure.

Another tachycardic condition is called supraventricular tachycardia or SVT.  SVT is a broad term used to describe many arrhythmias originating just above the ventricles. This arrhythmia usually causes bursts of rapid heartbeats that begin and end suddenly and can last from seconds to hours. Supraventricular tachycardia may cause the heart to beat between 160-200 times per minute (Mayo Clinic, p.4).  This arrhythmia is often caused by an underlying heart condition and is prevalent in young people. One cause of SVT is known as Wolff-Parkinson-White syndrome. This arrhythmia is caused by an extra electrical pathway between the atria and ventricles.  This pathway allows electrical impulses to pass freely between the atria and ventricles, causing short circuits and rapid heart rates.  Although SVT is generally non-life-threatening, symptoms range from an overall uncomfortable feeling to a racing heart.

While the previous arrhythmias occur in the atria of the heart, there are serious arrhythmias that occur at the ventricles.  The first arrhythmia is called ventricular tachycardia.  This fast, irregular beating of the heart is caused by abnormal electrical impulses that start out in the ventricles.  Often times these irregular beats are due to a problem with the impulse traveling around scar tissue in the heart from a previous heart attack.  Ventricular tachycardia can cause the heart to beat more than two hundred times a minute.  This arrhythmia occurs mostly in people with heart-related problems such as scars from a heart attack or damage to the ventricle muscle due to coronary artery disease.  An episode of ventricular tachycardia is a medical emergency and can worsen to lead into ventricular fibrillation and death.

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