Atrial Fibrillation (AF) or Afib as I like to call it, is the most common heart rhythm disorder and effects around 1per cent of the population. Its becomes even more common with increasing age. It seldom occurs in those under 40 years old, but occurs in up to 5% per cent of those over 80 years of age. It's favorite age to strike is "my age" late forties to early fifties. I am 52; mine started when I was 51 but could have been happening for months or even years unnoticed. It should be said Atrial Fibrillation is an electrical problem in the heart and not a plumbing problem like a normal heart attack or blockage.
Normal Heart Electrical Activity and What Goes Wrong in Atrial Fibrillation.
The heart is basically a large muscular pump that drives blood around the body. To do this correctly, the heart's chambers, there are four of them, must be precisely controlled electrically so they work together as one pumping unit. The normal heartbeat begins with the sinoatrial or Sinus Node a natural pacemaker located in the top right heart chamber (the right atrium). This electrical pulse spreads across both top chambers, the atria, causing them to contract. The contraction of the atria moves blood into the two ventricles, which are the main pumping chambers. The electrical signal is delayed by about one tenth of a second by a special structure called the atrioventricular (AV) node, and then spreads quickly across the ventricles to cause them to contract. This extra filling of the ventricles by the atria is not vital, but does serve to "prime the ventricular pump" and improve overall heart function.
These atria, which contain the heart's natural pacemaker, the SA node, are, the part of the heart involved in Atrial Fibrillation. The ventricles, the muscular part of the heart that actually pumps the blood are electrically isolated from the atria, and the only way the electrical signal can reach them is through the AV node.
Normal heart rhythm is termed sinus rhythm (no, nothing to do with your nose)
Most people have a resting heart rate of between 60 and 80 beats per minute. In Atrial Fibrillation, the atria contract rapidly and irregularly at rates of 400 to 600 beats per minute. As luck (see GOD) would have it, the AV node will not allow that many signals through to the ventricles; only about 1 or 2 out of every 3 Atrial beats passes to the ventricles. Even so the ventricles beat too fast, at rates of 110 to 180 beats per minute. (Mine was over 170!)
The Most Common Symptoms:
Feeling out of breath, reasonable since your heart is beating faster than if you were running a marathon.
Heart palpitations (a sudden pounding, fluttering, or racing feeling in the chest).
Lack of energy; feeling over-tired.
Dizziness (feeling faint or light-headed).
Chest discomfort (pain, pressure, or discomfort in the chest area)
In my case - inability to sleep lying down
Make It Slow Down!
The first thing you want to do is control the runaway heart rate. This is done with drugs and even cardioversion. (similar to the crash paddles and electric shock as seen on TV) The goal is to get the heart to beat in a unified, normal manner again. This is called Normal Sinus Rhythm and is the Holy Grail that all us Afibbers want to achieve.
I have only touched on the simple mechanics of a complicated problem. Please read the other articles as we go into greater detail and try to explain the real "nature of the beast" - Atrial Fibrillation.
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