ECG Dysrhythmias Updated March 2006: D. Tucker, RPh, BCPS
Mar 27, 2015
ECG Dysrhythmias
Updated March 2006: D. Tucker, RPh, BCPS
Overview
ECG waveforms Normal sinus rhythm Asystole Bradycardia Ventricular fibrillation Ventricular tachycardia
ECG Rhythm Strip
Electrocardiogram or ECG is used to measure the activity of the heart
ECG is used to represent the conduction of electrical impulses from the atria to the ventricles
ECG is used to characterize rhythms and conduction abnormalities of the heart
ECG Waveforms
P WaveElectrical activation (depolarization) of the right then left atrium due to discharge from the sinoatrial (SA) node
PR SegmentPassage of the impulse through the atrioventricular (AV) node and bundle of HIS
QRS Complex Electrical depolarization of the ventricles
ST Segment Plateau phase
T Wave Repolarization of the ventricle
U Wave Repolarization of the HIS-Purkinje system
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ECG Waveforms
Normal Sinus Rhythm
Normal impulse conduction through the heart
Normal sinus rhythm (NSR) is the standard against which all other rhythms are compared
NRS contains no ectopic or aberrant beats
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ECG Rhythms
Normal sinus rhythm
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ECG Rhythms
Asystole
Bradycardia
Ventricular fibrillation
Ventricular tachycardia
Asystole
Asystole is a cardiac standstill, i.e., flatline Asystole is the absence of electrical activity
in the venticles Asystole usually results from a prolonged
period of cardiac arrest without resuscitation
Asystole usually means the patient’s life has ended
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ECG Rhythms
Ventricular asystole
Bradycardia
Bradycardia is when the heart is < 60 beats/minute or when the heart rate is slower than expected
Sinus bradycardia usually occurs as a response to a reduced demand for blood flow
Signs and symptoms might include: Chest pain, shortness of breath Hypotension, pulmonary edema, congestive heart
failure
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ECG Rhythms
Sinus bradycardia
Ventricular Fibrillation
Ventricular fibrillation (VF) occurs as a result of electrical impulses coming from multiple ectopic pacemaker in the ventricles
VF results in no cardiac output as a result of producing no effective ventricular contractions
With VF the ventricular muscle quivers instead of contracting
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ECG Rhythms
Ventricular fibrillation
Ventricular Tachycardia
Ventricular tachycardia (VT) is a result of 3 or more ventricular contractions occur earlier than expected resulting in a ventricular rate of >10 beats/minute
VT usually preceeds VF Causes of VT include myocardial ischemia,
heart failure, drug toxicity from procainamide, quinidine, or cocaine
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ECG Rhythms
Ventricular tachycardia
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Name TheseECG Rhythms
A
B
D
E
C