Fibrillation of the heart
In the next part of the article we will discuss about
fibrillation of the heart,
one type of irregular heart rate and what are the consequences for our
body. Our heart is an organ that has a so called „automatism”, an
intrinsic property of the cardiac tissue to create its own electric
impulse, a signal that allows changes in cell metabolism in order to
generate cardiac muscle contraction and therefore pumping blood into the
arteries. This electric signal is generated in the sinus node (a
structure capable of generating electric signal, located in right
atrium) and then conducted through special structures until it reaches
the ventricles (heart chambers that pump blood into the arteries). If
these structures called pacemakers, can’t function normally, irregular
heart rate occurs and one of them is
fibrillation of the heart.
What is fibrillation of the heart ?
What is fibrillation of the heart? And how many types of
fibrillation of the heart
exist? There are two types of fibrillation of the heart: one is called
atrial fibrillation and another ventricular fibrillation. The difference
between these types of fibrillation of the heart is not just in name,
but also in origin and prognostic. The first type of fibrillation of the
heart-the atrial fibrillation-is an irregular heart rate generated in
multiple atrial cells (but not in the sinus node which is the „natural”
heart pacemaker).
Patients with atrial fibrillation may experience palpitations,
shortness of breath, chest pain, dizziness, drowsiness, fainting, but
there are some patients that don’t complain of any symptom and they are
diagnosed with the occasion of a routine medical check or when the
complications occur. Usually, atrial fibrillation allows blood clots to
form and they can flow in the arteries and block them, causing a
condition known as ischemia: the tissues won’t receive enough blood and
oxygen and cells start to die. In this situation, strokes, pulmonary
embolism (clots in the pulmonary arteries that can lead to death), limbs
ischemia (if untreated it can lead to amputation) can occur and can
lead to patient’s death, if immediate measures aren’t taken. On the
electrocardiogram, in atrial fibrillation there is an irregular heart
rate, without „P” waves (which are a mark of heart rate generated by
the sinus node) and the frequency of the heart beats can vary: low,
average or rapid.
If this arrhythmia was discovered at its beginning, a conversion to
the normal heart rate called sinus rhythm can be tried (either using
medication or with electric shocks). After this procedure succeeded,
other medication is needed in order to maintain the normal heart rate,
to control the normal frequency of the heart beats and prevent blood
clotting. In some patients, when the beginning of this arrhythmia is
unknown, doctors will use only drugs to control the heart rate (
beta blockers like metoprolole, atenolol;
digoxin-a
drug that increases heart contractility and also has antuarrthymic
properties, very often used in the treatment of atrial fibrillation,
calcium channel blockers
like amlodipine, verapamil, diltiazem) and prevent blood clotting.
Atrial fibrillation associated with rapid heart rate can be a severe
medical condition affecting the level of consciousness and the only way
to save patient life is the electrical conversion to the sinus rhythm
using electric shocks.
The other type of
fibrillation of the heart-ventricular
fibrillation is an irregular heart rate generated in the ventricular
cells and is not compatible with life, meaning that is one of the heart
rate that generates cardiac arrest. Heart stops from beating and
emergency measures of resuscitation are needed-cardiac massage
alternating with artificial oxygenation of lungs, using facial masks
with balloons or orotracheal intubation (which is preferred if it is
possible to perform), electric shocks, specific medication like
adrenaline, vasopressin, amiodarone. If in 30-45 minutes all these
maneuvers are unsuccessfully, then the patient is declared dead.
As we saw above, fibrillation of the heart is a major heart
disorder, that requires special attention, knowledge, maneuvers and
skills, since ventricular fibrillation is the most frequent cause of
cardiac arrest in adults.
