UNIT 1-ECG AND CODE MANAGEMENT Flashcards
Identify this rhythm
Artifact
- You will see artifact on the monitor when leads and electrodes are not sexure, or if there is muscle activity (shievering) or electrical interferce
- Artifact is a distortion of the baseline and waveforms seen on the ECG
What are your nursing interventions when you have Artifact on your ECG?
Because accurate interpretation of cardiac rhythm is difficult when artifiact is present. If artifact occurs, check the connections in the equipment. You may need to replace the electrodes if the conductive gel has dried out.
What are the four properties of cardiac cells that enable the conduction system to start an electrical impulse, send it through the cardiac tissue, and stimulate muscle contraction?
- Automaticity
- Excitability
- Conductivity
- Contractility
What is automaticity?
The ability to initate an impulse spontaneously and continuously
What is excitability?
Is the ability to be electrically stimulated
What is conductivity?
The aility to transmit an impusle along a membrane in an orderly manner
What is contractility?
The ability to respond mechanically to an impulse
Describe the function of the conduction system?
- Normal cardiac impulse begins in the sinoatrial (SA) node in the upper right atrium.
- It spreads over the atrial myocardium via interatrial pathways and internodal pathways, causing atrial contraction.
- The impulse then travels to the atrioventricular (AV) node, through the bundle branches. It ends in the purkinje fibers, which transmits the impulse to the ventricles.
Dysrhythias result from disorders of….
impusle formation, conduction of impulses or both
The SA node is the normally the ___1___ of the heart? firing at how many times per min?
- Pacemaker
- 60-100
What should we know about secondary pacemakers from another site?
NOT CLEAR ON THIS
Can fire in two ways
1. If the SA node fires more slowly than a secondary pacemaker, the electrical signals from the secondary pacemaker may “escape” The secondary pacemaker will then fire automatically at its intrinisc rate.
2. Another way that secondary pacemakers can start is when they fire more rapidly than the normal pacemaker of the SA node. “triggered beats” (early or late) may come from an ectopic focus or accessory pathway which is outside the normal conduction pathway in the atria, AV node or ventricles. The results in a dysrthmia, which replaces the normal sinus rhythm.
What is the intrinsic rate of the AV node or the His- Purkinje system?
AV node fires at a rate of 40 to 60 times per minute or the His-purkinje system at a rate of 20-40 times per min
The autonomic nervious system play an important role in the rate of….. in the cardiac system.
- Impulse formation
- Speed of conduction
- Strength of cardiac contraction
What are the components of the autonomic nervous system that affect the heart?
- Vagus nerve fibers of the parasympathetic nervous system and nerve fibers of the sympathetic nervous system
How does stimulation of the vagus nerve which a part of the parasympathetic nervous system affect the heart?
- Decreases rate of firing of the SA node
- Slowed impusle conduction of the AV node
How does stimulation of sympathetic nerves in the sympathetic nervous system affect the heart?
- Increases rate of SA node
- Increases impulse conduction of AV node
- Increase cardiac contractility
What are some sympathetic nervous system responses?
Stressed state
1. Pupils expand
2. Fast & shallow breathing
3. Heart pumps faster
4. Gut INACTIVE
What are some parasympathetic nervous system symptoms?
Calm
1. Pupils shrink
2. Slow deep breaths
3. Heart slows
4. Gut ACTIVE
What is Telemetry monitoring?
It is the observation of the patients HR and rhythm at a site distant from the patient
What are the 2 types of systems used for telemetry monitoring?
- Centralized monitoring
- Bedside advanced alarm systems
Centeralized monitoring system- ECG requires….
The nurse or a telemetry tech to contionusly observe a group of patients ECGs at a central location
Advanced alarm system bedside monitoring does not require….
Constant survallience. These systems have the cability of detecting and storing data. Advanced alarm systems provide different levels of detection of dysrhythimas, ischemia or infarction.
What do we need to remember about computerized monitoring systems?
They are not fail proof. We should frequently assess all monitored patients for any signs of hemodynamin instability
What should we know about the P wave?
- It is the 1st waveform that is normally seen.
- This wave should be upright (postive deflection) with a rounded top in lead
The P wave represents what part of the cardiac conduction system?
The P wave represents the SA node sending out an electrical impulse and represents atrial depolarization (contraction)
What should we know about the QRS wave (or complex)
- Normally follows the P wave.
- Can take on many different forms
- Normal QRS complexes are usually pointy and skinny in width.
The QRS complex represents what in the cardiac conduction system?
This complex represents ventricular depolarization (contraction) The ventricles depolarize from the endocardial layer (inside of the heart) to the epicardial layer (outermost layer of the heart)
How do we calculate the HR on an ECG
- Count the number of QRS complexes in 1 min
- QRS complexes in 6 seconds and multiply by 10
How does regularity determined when looking at the ECG?
Regularity can be determined by counting the boxes between the waveforms being measured, such as p wave to pwave or qrs to qrs complex (r to r). A regular rhythm will have the same number of boxes or equal space between waveforms or complexes
What are important concepts and questions to consider with our assessment of cardiac rhythm?
- Interpret the rhythm AND evaluate the clinical status of the patient
- Is the patient hemodynamically stable?
- Determine cause of dysrthymia
- This is a priority. For example, tachycardias may be the result of a fever and may cause a decrease in cardiac output and hypotension. Electrolyte distubances can cause dysrthmias and if not treated can be life-threatening
- Treat the patient, not the monitor
How should we assess the cardiac rhythm?
When assessing a cardiac rhythm, use a consistent and systematic approach.
1. Pwave
- look for its presence, is it upright or more inverted? Is there one for every QRS complex or more than one? Are there atrial fibrillatory or flutter waves?
2. P-R interval
- Is it normal duration or prolonged
3. Ventricular rate and rhythm?
- Is it regular or irregular
4. QRS complex
- Measure the duration of the QRS complex. Is it normal or prolonged
5. ST segment
- Is it isometric (flat), elevated, or depressed
6. Q-T interval
- Measure the duration of the Q-T interval is it normal or prolonged
7. T wave
- Is it upright or inverted
Identify this rhythm
Normal Sinus Rhythm which refers to a rhythm that starts in the SA node at a rate of 60-100 times per min and follows the normal conduction path way
Identify this dysrhythmias
Sinus Bradycardia
What do we need to know about sinus bradycardia
- Sinus bradycardia may be a normal sinus rhythm in aerobically trained athletes and in some people during sleep
- May be associated with some disease states
What is sinus bradycardia?
It occurs in response to a parasympathetic nerve stimulation and certain drugs, carotid sinus massage, valsalva maneuver, hypothermia, increased introcular pressure, vagal stimulation and administration of certain drugs like adrenergic blockers, calcium channel blockers
What are some common disease states associated with sinus bradycardia?
- Hypothyroidism
- Increased ICP
- Hypoglycemia
- Inferior myocardinal infarction (MI)
What are the manifestations of sinus bradycardia
- Hypotension
- Pale, cool skin
- Weakness
- Angina
- Dizziness or syncope
- Confusion or disorienatation
- SOB
Clinical significance of sinus bradycardia depends on how the patient tolerates it.
Symptomatic bradycardia refers to a HR that is….
Less than 60beats/min and is inadequate for the patients condition, causing the patient to experience symptoms
Treatment of sinus bradycardia includes?
- Atropine (anticholinergic drug) usually given to symptomatic patients
- Pacemaker
- Stop offending drugs
Identify this rhythm?
Sinus Tachycardia
Identify this rythem
Sinus Tachycardia
What do we need to know about sinus tachycardia
- The conduction pathway is the same in sinus tachycardia as that in normal sinus rhythm.
- The p wave is normal, procedes each QRS complex and has a normal shape and duration
- The P-R interval is normal and the QRS complex has a normal shape and duration
What is the rate of sinus tachycardia?
101-180beats/min
What causes sinus tachycardia?
- The discharge rate from the sinus node increases because of vagal inhibition or sympathetic stimulation
- Sinus tachycardia is associated with physiologic and psycholotic stressors such as exercise, fever, pain, hypovolemia, anemia, hypoxia, hypoglycemia, MI, heart failure, hyperthyridism, axiety and fear
- It can also be an effect of drugs such as epi, norepinephrine, atropine, caffeine, theophylline, or hydralazine, sudafed
What are manifestations of sinus tachycardia?
- Dizziness
- Dyspnea
- Hypotension
- Angina in patients with CAD
Clinical significance of sinus tachycardia depends on the patients tolerance of increased HR.
What is the treatment of sinus tachycardia
- Guided by cause for example for the patient who is experiencing tachycardia from pain… effective pain managment will treat tachycardia
- Vagal maneuver
- B-adrenergic blockers
- Metoprolol can be given to reduce HR and decrease myocardial oxygen consumption
Identify this rythem
PSVT- Paroxysmal Suptraventricular tachycardia
What is PSVT?
Is a dysrhythmia startin gin an etopic focus anywhere above the bifurcation of the bundle of HIS. Identification of the ectopic focus is often difficult even with a 12 lead.
What is the HR of someone experiencing PSVT
151-220 beats/min and the rhythm is regular or slightly irregular
What does the rhythm present with PSVT?
The P wave is often hidden in the preceding T wave. If seen, it may have an abnormal shape. The P-R interval may be shortned or normal, and the QRS complex is usually normal.
Identify this rhythm?
PSVT
What is a PSVT?
Paraoxysmal refers to an abrupt onset and ending. Termination is sometimes folled by a brief period of asystole
In a normal heart PSVT is associated with…
- Overexertion
- EMotional stress
- deep inspiration
- Stimulants such as caffeine and tobacco
PSVT is also associate dwith rheumatic heart disease, dig tox, CAD, or cor pulmonale
Identify this rhythm
Effect of Adenosine
1. Explain that the patient may feel chest pressure afte med is given
2. Injection site should be as close to heart as possible
3. Monitor patients ECG continously brief periods of asystole is common
4. Assess for flushing,dizziness, chest pain or palpitation
Identify this rhythm
Atrial flutter which is a atrial tachydysrthythmia identifed by recurring, regular sawtooth-shaped flutter waves that originate from a signle extopic focus in the right atrum or less commonly, the left atrium
What is the atrial rate of atrial flutter
200-350 beats per min
How is atrial flutter discribed?
- Atrial rhythm is regular and ventricular rhythm is usually regular
- The P-R interval is variable and not measureable
- The ORS complex is usually normal. Becuase the AV node can delay signal from the atria, there is usually some AV block in a fixed ratio of flutter waves to QRS complexes
Atrial flutter is typically associated with?
- Chronic lung disease
- Cardiomyopathy
- Hyperthyroidism
- Hypertention
- PE
- drugs
- digoxin, quindine, and epi
Can occur in a healthy heart but its rare.
What is the treatment of atrial flutter
- Pharmacologic agent
- Calcium channel blocker and b adrenergic blockers, antidysrthymic
- Electrical cardioverson may be performed to convert the atrial flutter to sinus rhythm in an emergency ( The patient is hemodynamically unstable) and electively.
- Radiofrequency catheter ablation is a treatment of choice for atrial flutter. Usuing a low-voltage, high-frequency form of electrical engery. The tissue is ablated (or destroyed) the dysrhythmia is ended and normal sinus rhythm is restored.
Patients with atrial flutter at at an increased risk of?
Stroke because of the risk of thrombus formation in the atria from the stasis of blood. Warfarin is given to prevent stroke in patients with atrial flutter
Identify this ryrthm
Atrial Fibrillation
- Most common clnically significant dysrhymia w/ respect to morbidity and mortality rates and economic impact
- The dysrhythmia may be paroxymal and end spontanously or be persistent lasting longer than 7days
What causes Afib and what can it cause if left untreated?
- As with atrial flutter– causes a decrease in CO and increased risk of stroke
- Often develops acutely with thyrotoxicosis, alcohol intoxication, caffeine, electrolyte disturbances, stress, cardiac surgery
- A fib results in a decrease in CO because of ineffective atrial contractions (loss of atrial kick) and/or a rapid ventricular response. Thrombi (clots) form in the atria because of blood stasis. An embolized clot may develop and pass to the brain, causing a stroke.
Afib is usually occurs in the patient with….
- Heart disease
- CAD
- Rheumatic heart disease
- Cardiomyopathy
- HTN heart disease
- HF
- Pericadiitis
When the ventricular rate is between 60-100 beats/min in a fib this is considered….
Atrial fibrillation with controlled ventricular response
example b
Atrial fibrillation with a ventricular rate greater than 100 beats/min is atrial fibrillation with a …… response
rapid or uncontrolled ventricular response aka AFIB with RVR
example c
What is the treatment of Atrial Fibrillation?
- Slow the ventrial response by increasing the AV block
- Drugs to control ventricular rate and/or convert to sinus rhythm (amiodarone and ibutilide most common)
- Electrical cardioversion
- Anticoagulation
- Radiofrequency ablation
- Maze procedure with cryoblation
Identify this rhythm?
PVC: Premature ventricular contraction which is a contraction coming from an ectopic focus in the ventricles. It is the premature (earlY)occurence of a QRS complex
A PVC is wide and distorted in shape compared to a qrs complex coming down the normal conduction pathway
What are PVCs that arise from different foci and appear in a different shape from each other called?
Mulifocal PVC
PVCs that have the same shape are called?
Unifocal PVCs
When every other beat is a PVC, the rhythm is called…
Ventricular bigeminy
When every third beat is a PVCs it is called…
Ventricular trigeminy
Identify this rhythm?
Ventricular Tachycardia
Ventricular rate in vtach is how many beats/min
150 to 250 beats/min
Rhythm may be regular or irregular
Patients in Vtach can be considered __1__ or __2__
- Stable (has a pulse)
- Unstable (no pulse)
Identify this rhythm
Ventricular fibrillation
Vfib which is a severe derangment of the heart rhythm characterized on ECG by irregular waveforms of varying shapes and amplitude. This represents the firing of multiple ectopic foci in the ventricle. Mechanically the ventricle is simply quievering with no effective contraction, and consequently no CO occurs.
Lethal dysrhythmia- HR not measurable. Irreglar and chaotic.
Identify this rhythm
Asystole- represent the total absence of ventricular electrical activity
Occasionally P waves are seen
No ventricular contraction occurs because depolarization does not occur
Identify this rhythm
HINT NO PULSE
Pulseless electrical activity- Is a situation in which organized, electrical activity is seen on the ECG, but there is no mechanical activity of the ventricles and the patient has NO PULSE
Prognosis is POOR unless the underlying cause is quickly identified and treated
Identify this rhythm
3rd degree AV heart block (complete heart block)- Constitutes one form of AV dissociation in which no impulses from the atria are conducted to the ventricles. THe atria are stimulated and contract independently of the ventricles. the ventricular rhythm is an escape rhythm, and the ectopic pacemaker may be above or below the vifurcation of the bundle of his
Atrial rate is usually a sinus rate of 60-100
Ventricle rate depends on the site on the site of the block. if its the AV node the rate is 40-60 beats/min and if its in the his-purkinje system it is 20-40 beats/min
Describe the characteristic of thrid degree AV heart block on the ECG
- Atrial and ventricular rhythms are regular but unreleated to each other
- The P wave has a normal shape
- The P-R interval is variable and there is no relationship between the Pwave and the QRS complex.
- THe QRS complex is normal if an escape rhythm is initated at the bundle of his or above it is widened if an escape rhythm is initatied below the bundle of his.
