1
Q
What are Dysrhythmias?
A
Disorders of formation or conduction (or both) of electrical impulses within heart—irregular or erratic rhythm
Can cause disturbances of:
* Rate
* Rhythm
or Both
Potentially can alter blood flow and cause hemodynamic changes
2
Q
What is a normal sinus rhythm?
A
- Ventricular and atrial rate : 60-100 bpm with a regular rhythm.
- QRS shape and duration is normal and between 0.6-0.12 sec.
- P wave normal and always in front of QRS with a 1:1 ratio.
PR interval is consistent and between 0.12-0.20 seconds.
3
Q
What is a sinus bradycardia rhythm?
A
- Ventricular & atrial rate < 60 bpm
The rest is normal.
4
Q
Who may have bradycardia as a normal HR?
A
Aerobically trained athletes such as marathon runners and distance swimmers.
5
Q
Which drugs may cause bradycardia?
A
Beta blockers and Calcium Channel Blockers.
6
Q
Which disease states are associated with Bradycardia?
A
Hypothyroidism
Increased intracranial pressure
Inferior myocardial infarction (MI)
Coronary Artery Disease
7
Q
Unstable and symptomatic bradycardia is frequently due to :
A
Hypoxemia.
8
Q
True / False
In patients with asymptomatic bradycardia, we normally don’t treat it.
A
True - treatment usually only happens when the patient becomes unstable and symptomatic.
9
Q
How do we treat bradycardia?
A
- Atropine (inotropic agent) - treatment of choice
- Pacemaker (increase HR) - for ongoing bradycardia
If caused by medication :
May need to be held
DC’d
Reduced
10
Q
How do we administer Atropine?
A
Typically give 0.5 mg via IV push every 3- 5 min until reaching max dose of 3 mg
11
Q
When Atropine is ineffective in treating bradycardia, what do we do next?
A
Pacemaker and medications that speed up the heart such as dopamine or epinephrine.
12
Q
What is a sinus tachycardia rhythm?
A
Ventricular & atrial rate > 100-120 bpm
Rest is mostly normal. P wave may be hidden in the T wave if HR is too fast.
13
Q
What may cause Tachycardia?
A
- Vagal inhibition or sympathetic stimulation (fight vs flight)
- physiologic and psychologic stressors
*effect of drugs
14
Q
Which physiologic and psychologic stressors may cause tachycardia?
A
Exercise,
fever,
pain,
hypotension,
hypovolemia,
anemia,
hypoxia,
hypoglycemia,
MI,
myocardial ischemia,
heart failure,
hyperthyroidism,
anxiety,
fear
15
Q
Which medications may cause tachycardia?
A
Epinephrine (EpiPen) - allergic reaction
Norepinephrine (Levophed) - ICU pressor
Atropine (AtroPen),
Caffeine,
Theophylline (Theo-Dur),
Hydralazine (Apresoline).
16
Q
How do we treat sinus tachy?
A
- If persistent and causing hemodynamic instability we would do a synchronized cardioversion.
- If stable - vagal maneuver bearing down, forceful and sustained coughing, applying cold stimulus to the face.
- IV beta blockers such as metoprolol to reduce HR and decrease myocardial oxygen consumption.
17
Q
What is Atrial flutter?
A
- Ventricular rate 75-150 bpm and Atrial rate 250-400 bp
- rhythm normally regular,
- QRS normally regular (may be irregular or absent).
- P wave is usually saw tooth shape - these are now called F (flutter) waves.
- PR interval is usually difficult to determine
- P to QRS ratio = 2:1, 3:1 or 4:1
18
Q
What are the s/s of Atrial flutter?
A
May be asymptomatic.
Symptomatic : chest pain, SOB, hypotension
19
Q
What is the treatment goal with A flutter?
A
Slow ventricular response by increasing AV block
20
Q
Which pharmacological agents are used to treat A flutter?
A
- Calcium channel blockers & β-blockers
- Anti-dysrhythmia drugs used to convert atrial flutter to sinus rhythm (e.g., ibutilide [Corvert]);
- To maintain sinus rhythm (e.g., amiodarone, flecainide [Tambocor], dronedarone [Multaq])
21
Q
Apart from pharmacological agents, how can we treat A flutter?
A
- Vagal maneuvers
- Adenosine trial - causes sympathetic block and slow conduction through AV node.
- Electrical cardioversion— Performed to convert atrial flutter to sinus rhythm (emergency & electively)
- Ablation
22
Q
How is Adenosine give?
A
Via rapid IV push followed by a 20 ml flush, and elevate the arm. Often by using a stopcock for quick injection and flush.
23
Q
What is an ablation?
How does it treat A flutter?
A
A cardiac ablation is a procedure where a cardiologist uses a catheter to destroy (ablate) a tiny area of heart tissue that is causing abnormal electrical signals.
The catheter is inserted through a vein (usually the femoral vein in the groin) and guided into the heart. Energy is delivered through the catheter tip to create a small scar
The scar tissue cannot conduct electricity, so it blocks the abnormal electrical pathway that was causing the arrhythmia.
24
Q
A flutter treatment is aimed at :
A
antithrombotic therapy
rate control
rhythm control
25
What is Atrial Fibrillation?
Ventricular rate : 120-200 bpm Atrial rate 300-600 bpm with irregular rhythms.
Normal QRS shape.
No discernable P waves and unable to measure PR intervals.
Many P waves to 1 QRS intervals.
26
What is A- fib with RVR?
A fib with rapid ventricular bpm. Patient will usually be very symptomatic.
27
A fib increases the risk of :
heart failure, myocardial ischemia, and embolic events
28
What are the treatment goals of A-fib?
* Preventing embolic events w/ use of anticoagulants.
* Rate control - Patient may still be in a-fib but with reduced rate.
* Cardioversion if needed.
29
Ventricular rate control is a priority for patients with A-fib, how do we achieve this?
* Calcium channel blockers (e.g., diltiazem)
* β-blockers (e.g., metoprolol),
* Digoxin (Lanoxin)
* Dronedarone
30
What medication do we use after a Cardioversion to maintain sinus rhythm?
Amiodarone
Ibutilide
31
If drugs or cardioversion do not convert atrial fibrillation to normal sinus rhythm, but rate is controlled and they are not symptomatic, then what do we do next?
long term anticoagulation therapy is needed - Warfarin is the drug of choice. We closely monitor INR with this treatment.
If using Apixaban/Eliquis, then lab monitoring is not necessary.
32
What is premature atrial contraction?
An extra atrial beat.
Ventricular and atrial rate depend on underlying rhythm. Both rhythm are irregular due to early P waves.
QRS usually normal.
P wave is early and can be hidden in the T wave.
Creates a PR interval shorter than normal, but still 0.12-0.2 sec.
R to QRS ratio 1:1
33
What may cause Premature Atrial Contractions?
* Caffeine
* Alcohol
* Nicotine
* Hypervolemia - stretching of atrial myocardium.
* Anxiety
* Hypokalemia (low potassium level)
* Hypermetabolic states (e.g., with pregnancy)
* Atrial ischemia, injury, or infarction
Patients may state that they can feel their heart skipping a beat.
34
What is medical management directed at to treat PAC?
Medical management is directed toward treating the underlying cause (e.g., reduction of caffeine intake, correction of hypokalemia).
35
More than 6 PAC's per minute may indicate what?
a worsening disease state or the onset of more serious dysrhythmias, such as atrial fibrillation.
36
What is a first degree atrioventricular block ?
* Prolongation of the PR interval (beginning of P wave to beginning of QRS) Ventricular and atrial rate and rhythm depend on underlying rhythm. .
* QRS shape usually normal. P wave in front of QRS has regular shape - just prolonged.
* PR interval > 0.20seconds - measurement is constant.
* Looks like normal sinus rhythm until you measure the PR interval which will be > 0.20
37
What usually causes a first degree AV block?
* Increased vagal tone
* Age related changes to the conduction system
* MI
* Rheumatic heart disease
* Congenital heart defects
* Electrolyte imbalances - Low potassium or magnesium
* Certain medications such as beta blockers or CCB's
* Sleep apnea
* Pacemaker malfunction
38
How do we treat AV block?
If asymptomatic, we just monitor.
39
What is a Premature Ventricular Contraction ?
It is the premature (early) occurrence of a QRS complex caused by an ectopic focus in the ventricles - extra beat from the ventricles.
HR depend on underlying rhythm.
Ventricular and atrial rhythm is irregular due to early QRS, creates one RR interval shorter than others.
QRS >0.12 sec w/ bizarre and abnormal shape.
P wave may be absent (hidden in QRS or T wave or infront of QRS)
PR interval : If P wave in front of QRS - PR interval <0.12
P to QRS ratio : 0:1 or 1:1
40
What are Multifocal PVCs?
PVCs that arise from different foci appear different in shape from each other
41
What are Unifocal PVCs?
PVCs that have the same shape
42
What are Ventricular bigeminy?
When every other beat is a PVC
43
What are Ventricular trigeminy?
When every third beat is a PVC
44
What are Couplet PVCs?
Two consecutive PVCs.
45
What is Ventricular tachycardia?
3+ PVCs in a row
46
What are PVC's associated with ?
* stimulants (energy drink)
* electrolyte imbalances
* hypoxia
* heart disease
47
Are PVCs harmful in normal hearts?
No, but can cause CO reduction which may lead to angina, and HF in diseased heart
48
True / False
PVCs May not generate a sufficient ventricular contraction to result in a peripheral pulse.
True
May be a apical-radial pulse deficit.
49
How do we treat PVCs?
Correct underlying cause (e.g., oxygen therapy for hypoxia, electrolyte replacement)
Medications:
β-blockers
amiodarone
Ablation
50
What is a Monomorphic Ventricular Tachycardia ?
* Consistent QRS shape and rate
* Ventricular rate 100-200, Atrial rate depend on underlying rhythm but may be hard to detect.
* Heart rhythm is regular.
* QRS >0.12 sec with bizzare & abnormal shape
* P to QRS ration is difficult to determine. More QRS than P
51
What is a Polymorphic Ventricular Tachycardia ?
* Varying QRS shapes and rhythms
* Also called Torsades de pointes (twisting of the points)
* Associated with prolonged QT interval of the underlying rhythm.
* Could be congenital or acquired.
* Could be due to a CNS disease or certain medications, low K= lvls, Ca or Magnesium.
* Usually pulseless.
52
What are medications that we want to monitor due to side effect of prolonged QT interval?
Ciprofloxacin
Erythromycin
Haloperidol
Lithium
Methadone
53
How do we treat Monomorphic or Polymorphic Ventricular Tachycardia?
* Stable w/Pulse → monitor w/antiarrhythmic
* Monophasic VT (symptomatic) → Cardioversion
* Pulseless VT → Defibrillation
54
For long term treatment of V-tach with an EF < 35%, what would we do?
Implanted Cardiac defibrillator (ICD)
55
For long term treatment of V-tach with an EF > 35%, what would we do?
Antiarrhythmic medication
56
What is V- fib?
Ventricular rate > 300 bpm
Irregular rhythm w/o specific pattern
Irregular and indescribable QRS shape and duration.
57
What is V-fib associated with?
* MI,
* ischemia,
* disease states,
* procedures
Patients are unresponsive, pulseless, and apneic
58
What happens if V-fib is not treated rapidly?
Death will occur.
59
How do we treat V-fib?
Immediate CPR and ACLS.
* Defibrillation
* Drug therapy (epinephrine followed by amiodarone)
60
What can V-fib be caused by?
Untreated or unsuccessfully treated V-tach
Cardiomyopathy
Valvular heart disease
Acid-base abnormalities
Electrolyte abnormalities
Electrical shock
61
What is Asystole?
Total absence of ventricular electrical activity.
Absent QRS complexes confirmed in two different leads
P waves may be apparent for a short duration
There is no heartbeat, no palpable pulse, and no respiration
62
How do we treat Asystole?
CPR w/ minimal interruptions
Identify underlying and contributing factors.
63
What are the H&T's that we should be checking to prevent Asystole?
Hypovolemia
Hypoxia
Hydrogen Ions (acidosis)
Hyper or Hypokalemia
Hypothermia
Hypoglycemia
Toxins
Tamponade
Tension pneumothorax
Thrombosis (pulmonary and coronary)
Trauma
64
What is Pulseless Electrical Activity?
Electrical activity on the ECG but no mechanical activity of the heart - no pulse.
65
How do we treat Pulseless Electrical Activity?
CPR
intubation
IV epinephrine
If underlying cause → treat and correct
NOT a shockable rhythm
66
Primary PEA is caused by?
A problem with the heart itself
67
What may secondary PEA be caused by?
* Blood loss
* Low BP
* Low oxygen levels
* Dehydration
* Electrolyte Problems
* Heart Attack
* Pulmonary embolism
* Hypothermia
* Trauma
* Toxic effect of prescription or recreational drugs
68
How do we treat PEA?
CPR
69
What do we use pacemaker treatment for?
* Permanent or temporary slow impulse formation
* Symptomatic AV or Ventricular conduction issues
* Cardiac Resynchronization therapy used for advanced HF - both ventricles are beign paced.
70
What are potential complications of Pacemaker use?
* Infection
* Bleeding or hematoma formation
* Dislocation of lead - common in newly placed pacemakers. Arms should be immobilized for a while to prevent dislocation.
* Skeletal muscle or phrenic nerve stimulation
* Cardiac tamponade
* Pacemaker malfunction
71
What is an ICD?
Implantable Cardioverter Defibrillator
* Device that detects and terminates life-threatening episodes of tachycardia and fibrillation
* Anti-tachycardia pacing
It responds to a rate that exceeds the predetermined level.
72
Who are the candidates for ICDs?
Patients who are high risk of V-tach or V-fi or who have survived cardiac death caused by V-fib.
Patients who experience symptomatic v-tach
Patients who have syncope secondary to V-tach
Patients w/ coronary artery disease who hare 40 days post MI with moderate to severe left ventricular dysfunction EF < 35%
Or patients who are diagnosed with non-ischemic cardiomyopathy for at least 9 months.
73
What are the nursing managements after a Permanent Electronic Device Insertion?
ECG assessment and monitoring.
CXR after procedure and prior to discharge to ensure leads are in the right places and to rule out pneumothorax complications.
Nursing assessment :
* CO and hemodynamic stability- VS
* Incision site
* Level of knowledge and education needs of family and patient
* Signs of ineffective coping
74
How is a Cardiac Ablation done?
* A thin tube (catheter) is threaded through a vein (often in the groin) up to the heart.
* The tip of the catheter delivers energy (heat via radiofrequency or extreme cold via cryoablation) to create a scar.
* Scar tissue doesn’t conduct electricity, so it blocks the “bad” electrical pathway.
75
When is a Cardiac Ablation normally used?
For arrhythmias that don’t improve with medications or cardioversion.
Commonly : a-fib, a-flutter or certain types of SVTs
76
What is the purpose of Cardioversion?
To "reset" the heart when it’s beating abnormally but the patient still has a pulse (e.g., atrial fibrillation, atrial flutter, stable VT with a pulse).
77
What type of energy delivery is done with Cardioversion?
the machine times the shock with the heart’s own rhythm (the R wave on the ECG).
78
Why is Cardioversion synchronized?
To avoid shocking during the heart’s vulnerable period (the T wave), which could cause dangerous rhythms.
79
What is normally the patient's state when doing Cardioversion?
Usually done when the patient is stable and awake → sedation is often used.
80
What is the purpose of Defibrillation?
To restart the heart when it has no effective pulse (e.g., ventricular fibrillation, pulseless VT).
81
What type of energy delivery is done with defibrillation?
Unsynchronized shock → delivered immediately, no need to time with the rhythm.
82
Why is Defibrillation done unsynchronized?
The patient has no organized rhythm, so there’s nothing to sync with.
83
What is normally the patient's state when doing Defibrillation ?
Emergency, patient is unconscious and pulseless.
84
True / False
Cardioversion is usually an elective procedure.
True
If elective and arrythmia's have lasted for longer than 48 hrs, we want to provide an anticoagulant for a few weeks before cardioversion,
85
What medication should be withheld 48 hrs prior to cardioversion and why ?
Digoxin should be held to ensure resumption of sinus rhythm w/ normal conduction
86
True / False
Patients do not need to be NPO prior to Cardioversion.
False
Patients should be NPO 4 hrs prior to cardioversion,
87
What are equipment that we want to ensure that we have in the room prior to cardioversion?
Ambu bag w/ suction
Intubation equipment
88
How can we tell if a cardioversion have been successful?
We'll see conversion of sinus rhythm and adequate peripheral pulses and BP.
89
What should we monitor post-procedure (cardioversion) ?
LOC
VS -until stable
ECG required during and after
90
What is given to patients after the initial or unsuccessful defibrillation?
Epi
This makes it easier to convert the arrythmia to normal sinus with the next defibrillation.
91
What medication can we give if the ventricular arrhythmia persists after defibrillation?
Antiarrhythmic medication such as amiodarone, lidocaine or magnesium.
92
Sleep Apnea can cause:
1st degree ❤️ block
