DYSRHYTHMIA RECOGNITION AND TREATMENT
Section I. DYSRHYTHMIA
a. Dysrhythmia is a disturbance in cardiac rhythm. Ninety percent of patients
with acute myocardial infarction (heart attack) will experience a form of cardiac
dysrhythmia during the first couple of weeks after their attack. Half of these will be life
threatening and will lead to cardiac arrest (sudden stoppage of adequate cardiac output)
unless properly treated. In order to analyze and treat a dysrhythmia correctly, you must
have a systematic approach to the electrocardiogram (EKG). Only after this process
has been completed can you make sound judgments as to which cardiac drug to
administer and when to defibrillate or use cardioversion.
b. When monitoring a patient's EKG, remember that you are monitoring
electrical activity of a heart, not mechanical activity. So, a pulse is always taken to
assure you of the heart's pumping action. Information learned from the EKG will be
used to help determine the treatment of the dysrhythmia. Dysrhythmia treatment could
be defibrillation, cardioversion, intravenous cardiac drugs, and/or CPR.
DYSRHYTHMIA = a disturbance in cardiac rhythm.
ELECTROCARDIOGRAM = monitors electrical activity of the heart.
a. Causes of Dysrhythmia. Dysrhythmias develop for various reasons
including acute myocardial infarction (heart attack), trauma, and drug reactions.
Drowning, near drowning, asphyxiation, and the patient's underlying medical conditions
can also cause dysrhythmias.
b. Significance of Dysrhythmia. There are several reasons why cardiac
dysrhythmias may be clinically significant. Heart rates below 40 to 50 beats per minute
lead to inadequate cardiac output and often precede electric instability of the heart. If
the sinus rate falls below 60 beats per minute, another conduction system may take
over. The Atrial Ventricular Junction (AV Junction) has an inherent rate of 40 to 60
beats a minute. The Ventricle has an inherent rate of 20 to 40 beats a minute. This
may lead to premature ventricular contractions and ventricular dysrhythmias. If a heart
rate is over 120 to 140 beats per minute, the heart must work harder. This causes
further myocardial ischemia (diminished blood flow). Tachycardias may be linked with a
drop in cardiac output which is secondary to decreased stroke volume, this lowered
volume being caused by the ventricles having less time to fill between heartbeats. And,