Asystole • There is a total absence of electrical activity in the heart
• The patient is clinically dead
• EKG tracing is referred to as straight line or flat line
• Complete absence of P waves and QRS complexes • True Asystole is an
absolute medical emergency o If your patient is speaking to you, they are
NOT in Asystole. 1. The following are common causes of an isoelectric line
that is not asystole i. Loose or disconnected leads ii. Loss of power to the
ECG monitor iii. Low signal gain on the ECG monitor
,Atrial Ectopic Beat (PAC—Premature Atrial caused by a premature depolarization of the atria originating from a focus
Contraction) outside of the sinus node. They are common and benign without any
additional indication of heart abnormality. Because these beats are
premature, the RR interval between the ectopic beat and the preceding
sinus beat is shorter than the RR interval between two sinus beats.
Causes:
• Atrial hypoxia; Atrial irritability
• Medications, especially stimulants
• Fatigue, anxiety
• Valve disease, COPD (dilated/hypertrophied atria)
• Digoxin toxicity, Hypokalemia
Treatment: Rarely treated; observe & document frequency & patient’s
condition
Note the difference in the P wave morphologies (shaded) for the sinus
beats (one, three, four, and six) and atrial ectopics (two and five). The
underlying rhythm is retained (indicated by arrows) by the compensatory
delay.
,
, Atrial Fibrillation In AF there is a complete absence of a Sino-Atrial stimulus which would
result in a P wave. Certain parts of the atria are depolarizing whilst other
parts are repolarizing causing ineffective quiver of the atrial muscle
resulting in a loss of atrial kick. As a result, the arterial and coronary
circulations lose at least 30% of their normal supply. The stimuli produced
are weak and partially depolarize the AV junction. This is enough to cause
a refractory period in which the AV node is unable to conduct other
impulses. Fibrosis and/or ischemia can cause damage to the conduction
tissue which then predisposes the patient to onset of arrhythmias.
Atrial rate unable to count. Ventricular rate variable
Rhythm HIGHLY irregular
P waves are absent; replaced by fibrillatory “F” waves
PR interval none
QRS narrow
ST and T waves frequently not identifiable
Causes can be:
• Idiopathic (cause unknown)
• Hypertension
• Mitral valve disease
• Cardiomyopathy
• Thyrotoxicosis
• Alcohol
• Sick Sinus Syndrome
• The patient is clinically dead
• EKG tracing is referred to as straight line or flat line
• Complete absence of P waves and QRS complexes • True Asystole is an
absolute medical emergency o If your patient is speaking to you, they are
NOT in Asystole. 1. The following are common causes of an isoelectric line
that is not asystole i. Loose or disconnected leads ii. Loss of power to the
ECG monitor iii. Low signal gain on the ECG monitor
,Atrial Ectopic Beat (PAC—Premature Atrial caused by a premature depolarization of the atria originating from a focus
Contraction) outside of the sinus node. They are common and benign without any
additional indication of heart abnormality. Because these beats are
premature, the RR interval between the ectopic beat and the preceding
sinus beat is shorter than the RR interval between two sinus beats.
Causes:
• Atrial hypoxia; Atrial irritability
• Medications, especially stimulants
• Fatigue, anxiety
• Valve disease, COPD (dilated/hypertrophied atria)
• Digoxin toxicity, Hypokalemia
Treatment: Rarely treated; observe & document frequency & patient’s
condition
Note the difference in the P wave morphologies (shaded) for the sinus
beats (one, three, four, and six) and atrial ectopics (two and five). The
underlying rhythm is retained (indicated by arrows) by the compensatory
delay.
,
, Atrial Fibrillation In AF there is a complete absence of a Sino-Atrial stimulus which would
result in a P wave. Certain parts of the atria are depolarizing whilst other
parts are repolarizing causing ineffective quiver of the atrial muscle
resulting in a loss of atrial kick. As a result, the arterial and coronary
circulations lose at least 30% of their normal supply. The stimuli produced
are weak and partially depolarize the AV junction. This is enough to cause
a refractory period in which the AV node is unable to conduct other
impulses. Fibrosis and/or ischemia can cause damage to the conduction
tissue which then predisposes the patient to onset of arrhythmias.
Atrial rate unable to count. Ventricular rate variable
Rhythm HIGHLY irregular
P waves are absent; replaced by fibrillatory “F” waves
PR interval none
QRS narrow
ST and T waves frequently not identifiable
Causes can be:
• Idiopathic (cause unknown)
• Hypertension
• Mitral valve disease
• Cardiomyopathy
• Thyrotoxicosis
• Alcohol
• Sick Sinus Syndrome
