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ATRIAL FIBRILLATION OVERVIEW
In Atrial
Fibrillation (A-Fib) the upper part of your heart beats (quivers) faster than
the rest of your heart. If you could look inside your chest, the top part of
your heart would be shaking like Jell-O
or beating more rapidly than the lower section of your heart. You feel an
uncomfortable flutter in your chest or like your heart is going to jump out of
your ribs or that your heart is "flip-flopping around." Your pulse is irregular
and/or more rapid than normal. Someone described their A-Fib as "...like a motor
idling too fast in my chest." You may feel lightheaded, very tired, have shortness of breath,
sweating and chest pain, and sometimes a distressing need for frequent urination
(it isn't clear how A-Fib and frequent urination are related). Some people
experience heart or chest pain.
Somewhere in your heart extra
electrical signals are being generated which cause the top part of your heart to
contract and quiver rapidly and irregularly (fibrillate) as many as 300-600
times a minute.

(If you'd like an explanation of the various parts of the EKG
signal, go to The EKG Signal.)
Your whole heart, however,
does not beat that fast. Your heart is a muscular pump divided into four
chambers---two atria located on the top and two ventricles on the bottom.
Normally each heart beat starts in the right atrium where a specialized group of
cells called the Sinus Node generates an electrical signal that travels down a
single electrical road (the AV Node or AV Junction) that connects the atria to
the ventricles below. This electrical signal causes the heart to beat. First,
the atria co ntract,
pumping blood into the ventricles.
Then, a fraction of a second later. the ventricles contract sending blood
throughout the body. Normally the heart beats at 60-80 times per minute. When a
doctor or nurse takes your pulse, he/she is counting contractions of your
ventricles.
In A-Fib, electrical signals from other parts of the heart
disrupt your heart's normal rhythm and cause the atria to beat or quiver on
their own sometimes as rapidly as 600 times a minute. However, only a small
number of these atrial beats make it through the AV Node which acts like a gate
to the ventricles. This is fortunate, because you couldn't live with a heart
beat that rapid. But some A-Fib beats do make it through the AV Node and make
your whole heart beat irregularly and/or faster than normal.
ATRIAL FLUTTER
Some people have Atrial Flutter along with their A-Fib, or
sometimes by itself without A-Fib. In Atrial Flutter the atria don't fibrillate but rather beat
faster than the ventricles but in a coordinated, regular rhythm. You can
consider Atrial Flutter as a more regular, milder variety of A-Fib. A-Flutter often,
though not always, originates in the right atrium, whereas A-Fib usually comes
from the left atrium. Here is an EKG of Atrial Flutter:
ECG 3 - atrial flutter

This ECG illustrated a heart in
atrial flutter. This has very distinct appearance. The "flutter waves" that we
expect to see in atrial flutter are noticeable throughout the ECG, but are very
easy to see in the rhythm strip. The rhythm is still regular, although this is
not always the case in AFL
130 (from
wolfminimaze.com)
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HOW SERIOUS AN ILLNESS IS A-FIB?
Stroke risk
If you have A-Fib, how sick are you? A-Fib may
feel weird and can be very frightening, but an attack of A-Fib by itself
usually isn't life threatening. The biggest
danger from A-Fib is stroke.
Because your heart isn't pumping out properly, blood can pool in your atria,
particularly in the
Left Atrial Appendage. Blood clots can form and travel to the brain
causing stroke.
If you have A-Fib and aren't being treated by a doctor, you are five-to-six times more likely to have a
stroke than the general population.106
Researchers estimate that 35% of patients with A-Fib will suffer a stroke107
(unless treated).
The American Heart Association states that
A-Fib is a major cause of stroke, especially if you're older. It estimates
that 15% of strokes come from untreated A-Fib. An A-Fib stroke is worse than
other causes of stroke. 23% of A-Fib stroke patients die, and 44% suffer
significant neurologic damage. This compares to only an 8% mortality rate
from other causes of stroke.132
There is also a danger of "silent"
A-Fib strokes where
stroke effects aren't evident but may appear like attention deficit,
forgetfulness, and senile dementia.72
Silent A-Fib is very common. Up to 30% of A-Fib patients are unaware they
have A-Fib.140
25% of those with A-Fib stroke had no prior diagnosis of A-Fib.141,142
Talk to your doctor about blood thinners
If you have A-Fib, it is most important to talk to your
doctor about taking a blood
thinner like aspirin (Plavix, Ticlid) or warfarin (Coumadin) to help prevent these clots from
forming. (Plavix and
Ticlid are antiplatelet drugs like aspirin but they are not the same or
interchangeable with aspirin. If your doctor prescribes Plavix or Ticlid, you
should not substitute aspirin for them.)
However, especially if you are young, active, and have an otherwise
normal heart, you and your doctor may decide your A-Fib stroke risk is low,
and you don't need a blood thinner. (For a more detailed discussion of
anticoagulation for patients with A-Fib, go to Dr. Waldo's presentation
2006 ACC/AHA/ESC Guidelines for the Treatment of A-Fib - Update and Critique:
Impact of A-Fib Guidelines on Clinical Practice.)
(There are two main types of stroke. A clot in a narrow blood
vessel is called an "ischemic" stroke and is the kind that often occurs in
A-Fib. Almost 85% of strokes are ischemic. A "hemorrhagic" stroke occurs when
a blood vessel leaks blood into the brain.)56
A-Fib damages your heart, brain
and other organs
If you have A-Fib, you
may not be getting enough blood to your brain and other organs which may cause
weakness, fatigue, dizziness, fainting spells, and shortness of breath.
Recent studies indicate that
A-Fib
reduces mental abilities and may lead to dementia.98 Permanent (Chronic) A-Fib has been found to significantly reduce blood flow to
the brain and brain function.76
A-Fib
untreated can also lead to more serious heart rhythm problems and to heart
failure77. Prolonged A-Fib
episodes may stretch and weaken the heart muscle. The ability of the atria to
contract is diminished (called "ejection fraction"). If you have A-Fib, you're more likely to
die than someone in normal heart rhythm. A-Fib nearly doubles your chances of
death.61
A-Fib remodels your heart and
is a progressive disease
It's important to be treated as
reasonably soon as possible. A-Fib begets A-Fib. In a process called "remodeling," your
heart actually changes if you have A-Fib long enough. The fast, abnormal
rhythm in your atria causes electrical changes and enlarges your atria. Your
heart develops fibrosis, the formation of fibrous tissue in the heart. Your
A-Fib episodes become more frequent and longer, often leading to continuous
(Chronic) A-Fib. However, some people never progress to more serious A-Fib
stages.
But even with Chronic A-Fib, people have been cured, and
this remodeling of the heart partially or almost completely reversed [see
Left Atrial Function...After Catheter Ablation].
If you have occasional episodes of
A-Fib and don't have other serious heart problems, you most likely have Focal
A-Fib and stand a good chance of being cured by Pulmonary Vein Ablation. But don't delay! The longer you wait to be treated,
the worse your A-Fib could get. (If you've had A-Fib for six weeks, your A-Fib
probably hasn't progressed very much. But if you've had A-Fib for six years,
you should get treated as reasonably soon as possible.)
HOW DO YOU GET A-FIB (CAUSES)? 
Nearly three million people
in the U.S. have A-Fib. By the year 2050, the number will be 5.6 million.71 This year there will be over
340,000 new cases in the US. A-Fib is the most common heart arrhythmia.146 Americans
over 40 have a one in four lifetime risk of developing A-Fib.82
If you've had other heart problems, this could lead to
diseased heart tissue which generates the extra A-Fib pulses.
Hypertension (high blood pressure) and Mitral Valve disease seem to be related
to A-Fib, possibly because they stretch and put pressure on the pulmonary veins
where most A-Fib originates. Many people ("up to
40% of patients"42) get
A-Fib after open heart
surgery.
"Pericarditis"---inflammation of the pericardium, a sack-like membrane
surrounding the heart---can lead to A-Fib.
Heavy drinking may trigger A-Fib, what hospitals call
"holiday heart"---the majority of A-Fib admissions occur over weekends or
holidays when more alcohol is consumed.
Extreme fatigue, emotional
stress, severe infections, severe pain, and illegal drug use can trigger A-Fib.
Low or high blood and tissue
concentrations of minerals such as potassium, magnesium and calcium can trigger A-Fib.
Thyroid problems
(hyperthyroidism), lung disease, reactive hypoglycemia, viral infections, and
smoking can trigger A-Fib. Smoking cigarettes raises the risk of developing
A-Fib even if one stops smoking, possibly because past smoking leaves behind
permanent fibrotic damage to the atrium which makes later A-Fib more likely.129
Some
research has identified a Familial A-Fib where A-Fib is passed on genetically28
but it is relatively rare.
Some cases have
been reported where antihistamines, bronchial inhalants, local anesthetics,
tobacco use, MSG, cold
beverages, and even sleeping on one's left side or stomach are said to have triggered A-Fib.
The author used to include caffeine (coffee, tea, sodas, etc.) in this list, but
some research suggests that coffee and caffeine in moderate to heavy doses (2-3
cups to 10 cups/day) may not trigger or induce A-Fib.144,
145 Coffee (caffeine) may indeed be
antiarrhythmic and may reduce propensity and inducibility of A-Fib both in
normal hearts and in those with focal forms of A-Fib.143
(Thanks to Karl for calling our attention to these articles.)
Chocolate in large amounts may trigger attacks. Chocolate contains a little
caffeine, but also contains the structurally related theobromine, a milder
cardiac stimulant (thanks to Prof. Phil Page from the UK for this info). GERD
(heartburn) and other stomach problems (like H. pylori) may be related to or
trigger A-Fib. If so, antacids and proton pump inhibitors like Nexium may help
your A-Fib (Thanks to Ian Betts for this observation). A report from England suggests that the veterinary antibiotic "Lasalocid"
found in eggs and poultry meat may cause or trigger A-Fib.65
One person writes that hair regrowth products seem to trigger his A-Fib.
Recent research indicates sleep apnea (where your breathing
stops while you are
sleeping) may contribute to A-Fib, probably by causing stress to the Pulmonary
Vein openings.90 Many
people have sleep apnea and don't know it. Your significant other can tell you
if you snore a lot, which is often a sign of sleep apnea. If you have A-Fib, it
might be wise to have yourself checked for sleep apnea. (Thanks to David Embler
for this observation.) (Gail writes that both her sleep apnea and her A-Fib were
cured by a
CPAP [Continuous Positive Airway Pressure] breathing machine. E-mail:
gail(at)bonairwine.com [the "@" is written as "(at)" to avoid access by spam
mailing lists].)
If your
A-Fib episodes occur usually at night, after a meal, when resting after
exercising, or when you have digestive problems, you may have Vagal A-Fib. (See
Vagal A-Fib)
Athletes are more prone to A-Fib
perhaps because
they have larger hearts where there is more room for these extra electrical
signals to develop and propagate, and possibly because of the extra pressure
they put on their pulmonary veins through aerobic exercise. A-Fib is often found
in tall people, particularly basketball players.89 Men get
A-Fib more than women.
A-Fib is associated with aging of
the heart. As patients get older, the prevalence of A-Fib increases, roughly
doubling with each decade. 2-3% of people in their 60s, 5-6% of people in their
70s, and 8-10% of people in their 80s have A-Fib.68,69,70
This suggests that A-Fib may be related to degenerative, age-related changes in
the heart. Inflammation may contribute to the structural remodeling associated
with A-Fib.82
But
in many A-Fib cases (around 50% of Paroxysmal A-Fib44),
there is no currently discernible cause or trigger (called "Lone" or "Idiopathic A-Fib").26
(Some research suggests that inflammation may initiate Lone A-Fib.84)
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CURING A-FIB
The key to stopping A-Fib is to eliminate the extra
electrical pulses A-Fib generates. Medications in general aren't very
effective or have serious side effects. Sometimes an electrical shock
can return your heart beat to normal. (For a more detailed discussion of cures
for A-Fib, see
CURES FOR
ATRIAL FIBRILLATION)
A very effective treatment to eliminate these extra
electrical pulses is Pulmonary Vein Ablation
(Isolation). Under sedation anesthetic (you aren't
knocked out) or general anesthesia a soft, flexible tube with an electrode at the tip is inserted
into a vein or artery in your groin
and moved into your heart. This catheter is directed to the precise
location(s) in your heart that is producing these extra signals. Using
radiofrequency (RF), laser, cryo or ultrasound energy these area(s) are burned off
or isolated from your heart. All you feel is a little warmth or tingling.
After the procedure you may feel a little tenderness or have some bruising in
your groin where the catheter was inserted. Otherwise the procedure is
usually painless, because there are no nerve endings inside the heart or blood
vessels. See Cures for a discussion of the current
methods of treating A-Fib.
A partial alphabetical list of medical facilities in the U.S.
performing Pulmonary Vein Ablation (Isolation) is found
under Facilities. See also
Finding A Doctor.
Back to Top (Last updated 5/11/09)
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