Arrhythmias
Associated With A Myocardial Infarction The initial phase of an myocardial
infarction (=MI) is particularly vulnerable for developing arrhythmias until the
scarred area in the heart muscle consolidates. This usually takes until 7 to 10
days from the beginning of a heart attack. In the first 3 days following an MI
this danger is highest and usually patients are kept in an Intensive Care Unit
setting or a Coronary Care Unit of a larger hospital. There the patient is hooked
up to the latest testing and heart monitoring. Telemetry is a newer technology
where the patient can mobilize, but is connected through radio waves to a central
monitoring station. An intravenous hookup is in place so that in an emergency
there is instant access to a vein and medication can be given very quickly. When
dangerous irregular heart rhythms develop and are detected on the monitor screen,
appropriate antiarrhythmic medication can be given intravenously, which then rapidly
stabilizes an otherwise very precarious cardiac situation. The cardiac care nurse
will check vital signs frequently in order to monitor the pump function of the
heart.
Ventricular
fibrillation: The worst scenario is the sudden occurrence of ventricular
fibrillation. This is a deadly arrhythmia where the heart muscle fibers
contract in a completely dissociated pattern so that the heart as a whole can
no longer pump blood. The patient becomes dizzy, then unconscious and would
die in only a few minutes, if left alone. The health care providers in the Coronary
Care Unit are prepared for this emergency and will quickly use a defibrillator
where a pulse of electric current is administered via electric paddles, which
are pressed against the skin of the chest wall. This depolarizes all of the heart
muscle fibers and the electrical impulses originating in the sinus node can then
start again, which makes the heart beat regularly on its own again. What a thrill
it is for the health care workers when such a maneuver is successful! With no
other underlying cause such a defibrillation procedure works miracles. It really
can safe lives. However, it has to be applied before the patient accumulates
a lot of lactic and carbonic acid from a lack of breathing and before the heart
muscle becomes too deplete of oxygen. In that condition the heart muscle does
not want to respond and options are running out very quickly. Ambulance drivers
today are trained to use portable defibrillators for emergencies such as these
and this has improved the survival among heart attack victims significantly. Unfortunately
many heart attack patients still die before they ever reach the hospital. It is
only in the last decade that the idea of the emergency response team that carries
some of the hospital equipment has caught on. The U.S. and Canada have been
pioneers in the introduction of this technology in emergency response teams outside
of hospitals. Thousands of lives have already been saved that way and thousands
more will be saved in future by bringing this service more and more to the rural
areas. Call 911 when you see a person with a heart attack, a seizure or a stroke.
Then the ambulance team can come and help to stabilize that person and rush him
or her to the hospital where more medical help is available. In order to establish
a "life chain" it is important that a significant percentage of the
population knows cardiopulmonary resuscitation (CPR). This way a person in distress
can be kept alive even when the heart is not beating on its own. Next the community
emergency response team can diagnose what rhythm the patient's heart is in using
the modern equipment. This information will then dictate what therapy is instituted.
In a straight forward case the ambulance attendant can proceed with the defibrillator.
If things are more complex, information may have to be relayed to the hospital
and a cardiologist may have to give radio instructions to the attendant on how
to proceed further.Often, by the time the ambulance arrives at the hospital,
the patient is already stabilizing because the anoxia (lack of oxygen in the tissues)
has been reversed. The underlying condition, which lead to the emergency, can
then be addressed in the hospital setting. With such a life chain as just described
the outcome has become much better. But without a preventative approach within
the population the figures of success will not exceed the 50 to 60 % success rate
on the long term. We have come a long way from figures of 5 to 10 % success in
the past before the emergency response team was established. However, when people
are overweight, smoke and do not exercise , the resulting disease process in the
heart, lungs and blood vessels is so severe that the overall outcome even with
the best emergency response team cannot be successful. Bad disease leads to bad
results. Without good ingredients a cook cannot bake a good cake. Medicine is
not any different: You need good basic tissues to have a good long term outcome
(Ref. 1, p. 1710). More info
on heart attacks can be found through this link. | 
