Relias Assessments Assistance Material
DYSRHYTHMIAS
EKG interpretation
One of the most useful and commonly used diagnostic tools is electrocardiography
(EKG) which measures the heart's electrical activity as waveforms. An EKG uses
electrodes attached to the skin to detect electric current moving through the heart.
These signals are transmitted to produce a record of cardiac activity. Arrhythmia or
dysrhythmia are disturbances in the normal cardiac rhythm of the heart which occurs as
a result of alterations within the conduction of electrical impulses. These impulses
stimulate and coordinate atrial and ventricular myocardial contractions that provide
cardiac output.
Sinus Tachycardia
Sinus tachycardia is a heart rate greater than 100 beats per minute that originated from
the sinus node.
Rate: 100 to 180 beats per minute
P Waves precede each QRS complex
PR interval is normal
QRS complex is normal
Conduction is normal
Rhythm is regular
Causes of sinus tachycardia may include exercise, anxiety, fever, drugs, anemia, heart
failure, hypovolemia and shock. Sinus tachycardia is often asymptomatic. Management
however is directed at the treatment of the primary cause. Carotid sinus pressure
(carotid massage) or a beta blocker may be used to reduce heart rate.
Sinus Bradycardia
Sinus bradycardia is a heart rate less than 60 beats per minute and originates from the
sinus node (as the term "sinus" refers to sinoatrial node). It has the following
characteristics
Rate is less than 60 beats per minute
P Waves precede each QRS complex
PR interval is normal
QRS complex is normal
Conduction is normal
Rhythm is regular
Causes may include drugs, vagal stimulation, hypoendocrine states, hypothermia, or
sinus node involvement in MI. This arrhythmia may be normal in athletes as they have
quality stroke volume. It is often asymptomatic but manifestations may include:
syncope, fatigue, dizziness. Management includes treating the underlying cause and
administering anticholinergic drugs like atropine sulfate as prescribed.
Premature Atrial Contraction
Premature Atrial Contraction are ectopic beats that originates from the atria and they
are not rhythms. Cells in the heart starts to fire or go off before the normal heartbeat is
supposed to occur. These are called heart palpitations and has the following
characteristics:
Premature and abnormal-looking P waves that differ in configuration from normal P
, waves
QRS complex after P waves except in very early or blocked PACs
P waves often buried in the preceding T wave or identified in the preceding T wave.
Causes includes coronary or valvular heart diseases, atrial ischemia, coronary artery
atherosclerosis, heart failure, COPD, electrolyte imbalance and hypoxia. Usually there
is no treatment needed but may include procainamide and quinidine administration
(antidysrhythmic drugs) and carotid sinus massage.
Atrial Flutter
Atrial flutter is an abnormal rhythm that occurs in the atria of the heart. Atrial flutter has
an atrial rhythm that is regular but has an atrial rate of 250 to 400 beats/minute. It has
sawtooth appearance. QRS complexes are uniform in shape but often irregular in rate.
Normal atrial rhythm
Abnormal atrial rate: 250 to 400 beats/minute
Sawtooth P wave configuration
QRS complexes uniform in shape but irregular in rate
Causes includes heart failure, tricuspid valve or mitral valve diseases, pulmonary
embolism, cor pulmonale, inferior wall MI, carditis and digoxin toxicity.
Management if the patient is unstable with ventricular rate of greater than 150 bpm,
prepare for immediate cardioversion. If patient is stable, drug therapy may include
calcium channel blocker, beta-adrenergic blockers, or antiarhythmics. Anticoagulation
may be necessary as there would be pooling of blood in the atria.
Atrial Fibrillation
Atrial fibrillation is disorganized and uncoordinated twitching of atrial musculature
caused by overly rapid production of atrial impulses. This arrhythmia has the following
characteristics:
Atrial Rate: 350 to 600 bpm
Ventricular Rate: 120 to 200 bpm
P wave is not discernible with an irregular baseline
PR interval is not measurable
QRS complex is normal
Rhythm is irregular and usually rapid unless controlled.
Causes includes atherosclerosis, heart failure, congenital heart disease, chronic
obstructive pulmonary disease, hypothyroidism and thyrotoxicosis. Atrial fibrillation may
be asymptomatic but clinical manifestation may include palpitations, dyspnea, and
pulmonary edema. Nursing goal is towards administration of prescribed treatment to
decrease ventricular response, decrease atrial irritability and eliminate the cause.
Premature Junctional Contraction
Premature Junctional Contraction (PJC) occurs when some regions of the heart
becomes excitable than normal. It has the following characteristics.
PR interval less than 0.12 seconds if P wave precedes QRS complex
QRS complex configuration and duration is normal
P wave is inverted
Atrial and ventricular rhythms irregular
Causes of PJC may include myocardial infarction or ischemia, digoxin toxicity,
excessive caffeine or amphetamine use. Management includes correction of underlying
cause, discontinuation of digoxin if appropriate.
DYSRHYTHMIAS
EKG interpretation
One of the most useful and commonly used diagnostic tools is electrocardiography
(EKG) which measures the heart's electrical activity as waveforms. An EKG uses
electrodes attached to the skin to detect electric current moving through the heart.
These signals are transmitted to produce a record of cardiac activity. Arrhythmia or
dysrhythmia are disturbances in the normal cardiac rhythm of the heart which occurs as
a result of alterations within the conduction of electrical impulses. These impulses
stimulate and coordinate atrial and ventricular myocardial contractions that provide
cardiac output.
Sinus Tachycardia
Sinus tachycardia is a heart rate greater than 100 beats per minute that originated from
the sinus node.
Rate: 100 to 180 beats per minute
P Waves precede each QRS complex
PR interval is normal
QRS complex is normal
Conduction is normal
Rhythm is regular
Causes of sinus tachycardia may include exercise, anxiety, fever, drugs, anemia, heart
failure, hypovolemia and shock. Sinus tachycardia is often asymptomatic. Management
however is directed at the treatment of the primary cause. Carotid sinus pressure
(carotid massage) or a beta blocker may be used to reduce heart rate.
Sinus Bradycardia
Sinus bradycardia is a heart rate less than 60 beats per minute and originates from the
sinus node (as the term "sinus" refers to sinoatrial node). It has the following
characteristics
Rate is less than 60 beats per minute
P Waves precede each QRS complex
PR interval is normal
QRS complex is normal
Conduction is normal
Rhythm is regular
Causes may include drugs, vagal stimulation, hypoendocrine states, hypothermia, or
sinus node involvement in MI. This arrhythmia may be normal in athletes as they have
quality stroke volume. It is often asymptomatic but manifestations may include:
syncope, fatigue, dizziness. Management includes treating the underlying cause and
administering anticholinergic drugs like atropine sulfate as prescribed.
Premature Atrial Contraction
Premature Atrial Contraction are ectopic beats that originates from the atria and they
are not rhythms. Cells in the heart starts to fire or go off before the normal heartbeat is
supposed to occur. These are called heart palpitations and has the following
characteristics:
Premature and abnormal-looking P waves that differ in configuration from normal P
, waves
QRS complex after P waves except in very early or blocked PACs
P waves often buried in the preceding T wave or identified in the preceding T wave.
Causes includes coronary or valvular heart diseases, atrial ischemia, coronary artery
atherosclerosis, heart failure, COPD, electrolyte imbalance and hypoxia. Usually there
is no treatment needed but may include procainamide and quinidine administration
(antidysrhythmic drugs) and carotid sinus massage.
Atrial Flutter
Atrial flutter is an abnormal rhythm that occurs in the atria of the heart. Atrial flutter has
an atrial rhythm that is regular but has an atrial rate of 250 to 400 beats/minute. It has
sawtooth appearance. QRS complexes are uniform in shape but often irregular in rate.
Normal atrial rhythm
Abnormal atrial rate: 250 to 400 beats/minute
Sawtooth P wave configuration
QRS complexes uniform in shape but irregular in rate
Causes includes heart failure, tricuspid valve or mitral valve diseases, pulmonary
embolism, cor pulmonale, inferior wall MI, carditis and digoxin toxicity.
Management if the patient is unstable with ventricular rate of greater than 150 bpm,
prepare for immediate cardioversion. If patient is stable, drug therapy may include
calcium channel blocker, beta-adrenergic blockers, or antiarhythmics. Anticoagulation
may be necessary as there would be pooling of blood in the atria.
Atrial Fibrillation
Atrial fibrillation is disorganized and uncoordinated twitching of atrial musculature
caused by overly rapid production of atrial impulses. This arrhythmia has the following
characteristics:
Atrial Rate: 350 to 600 bpm
Ventricular Rate: 120 to 200 bpm
P wave is not discernible with an irregular baseline
PR interval is not measurable
QRS complex is normal
Rhythm is irregular and usually rapid unless controlled.
Causes includes atherosclerosis, heart failure, congenital heart disease, chronic
obstructive pulmonary disease, hypothyroidism and thyrotoxicosis. Atrial fibrillation may
be asymptomatic but clinical manifestation may include palpitations, dyspnea, and
pulmonary edema. Nursing goal is towards administration of prescribed treatment to
decrease ventricular response, decrease atrial irritability and eliminate the cause.
Premature Junctional Contraction
Premature Junctional Contraction (PJC) occurs when some regions of the heart
becomes excitable than normal. It has the following characteristics.
PR interval less than 0.12 seconds if P wave precedes QRS complex
QRS complex configuration and duration is normal
P wave is inverted
Atrial and ventricular rhythms irregular
Causes of PJC may include myocardial infarction or ischemia, digoxin toxicity,
excessive caffeine or amphetamine use. Management includes correction of underlying
cause, discontinuation of digoxin if appropriate.
