Final cardiac Flashcards
What is the conduction pathway in the heart
- SA node
- Intra atrial pathways
- AV node
- Bundle of His
- Left and right bundle branches
- Purkinje fibers
Does the parasympathetic nervous system increase your SA node or decrease? What about the sympathetic nervous system?
The parasympathetic system slows the SA node (it’s like the brake)
The sympathetic system increases the SA node (it’s like the gas)
What do the waves and the intervals stand for on an ECG
P wave = depolarization of the atria
PR interval = time for the impulse to spread through the atria
QRS = depolarization of the ventricles
ST = time between ventricular depolarization and repolarization
T wave = repolarization of the ventricles
QT interval = time for entire depolarization and repolarization of the ventricles
How many seconds is a typical strip
6 seconds
How many seconds is a big box and how many seconds is a little box
Big box = 0.2 seconds
Little box = 0.04 seconds
What is the rate of the SA node and the atria
60-100
What is the rate of the AV node and bundle of His
40-60
What is the rate of the bundle branches and purkinje
20-40
How many seconds should the PR interval be?
0.12-0.20 seconds (about 3-5 little boxes)
How many seconds should the QRS complex be
Less than 0.12 seconds (less than 3 little boxes)
What is artifact
Artificial ECG info - maybe a lead is lose, pt is up walking around, etc…
What is the absolute refractory period? Why is it important? What part of the ECG wave is it?
When excitability is zero and the heart cannot be stimulated (important with cardioversion - we don’t want to shock the heart when it’s doing something). It’s from Q to the T wave.
How do we diagnosis dysrhythmias? (probably don’t need to memorize - just be familiar just in case)
- Holter monitoring (usually only worn for 24 hours)
- ZIO Patch (usually worn for 14 days)
- Event recorder monitoring (you can control when it records)
- Exercise treadmill testing
- Signal-averaged ECG (multiple ECG’s use averages for dx)
- Electrophysiologic study (“EP Study” with the use of catheters to study the origin of the dysrhythmia)
What are the steps when we look at a rhythm?
- Is the rate regular or irregular? Is it regularly irregular?(R wave to R wave)
- Rate? (multiply the R waves by 10)
- Is there one P wave in front of every QRS? Do they all look the same?
- Is the PR interval normal and consistent?
- Is the QRS narrow or wide?
- Is there a T wave?
How do we know someone is in sinus bradycardia
Rate is less than 60
What can cause sinus bradycardia 9
- Carotid sinus massage
- Hypothermia
- Hypothyroidism
- Increased intracranial pressure
- Obstructive jaundice
- MIs
- Increased vagal tone (when a pt is bearing down and passes out on toilet)
- Administration of parasympathomimetic drugs
- Drugs like beta blockers and CCBs.
What are symptoms of bradycardia
- Hypotension
- Pale, cool skin
- Weakness
- Angina
- Dizziness or syncope
- Confusion or disorientation
- Shortness of breath
(anything that you would see with decreased cardiac output)
What is our tx for bradycardia 4
- Stop offending drug (like beta blocker or CCB)
- IV atropine (1mg) (may or may not work depending on what’s causing the bradycardia)
- Pacemaker
- Dopamine or epinephrine infusion
How do we know someone is in sinus tachycardia
Their HR is over 100
What things can cause sinus tachycardia
Yes - here are the signs
- Exercise
- Pain
- Hypovolemia (Heart is working faster and faster to try and increase cardio output because volume is low)
- Myocardial ischemia (with any kind of ischemia, heart works harder to get blood to that area)
- Heart failure (HF)
- Fever
- Anxiety
- Hyperthyroidism
- Effects of drugs: Levophed, atropine, caffeine, theophylline, hydralazine, pseudoephedrine
How can we treat sinus tachycardia 2
- Treat the underlying cause! (such as pain, fever, hypovolemia (someone is really dehydrated, give them fluids, heart rate goes down)
- Vagal maneuver (have them bear down, blow into a straw)
- Drugs (beta blockers, adenosine, CCBs)
What do (premature atrial contraction) PACs look like
- Caused by ectopic focus (starting from somewhere other than the SA node)
- The p wave looks different, because it is firing prematurely from a different place in the heart (not the SA node), and then it will be followed by a narrow QRS
- This beat occurs sooner than the next expected beat
How can we tell the difference between a PAC and PVC
Since the PAC is coming from the atrium, the QRS will be narrow, versus a PVC, which is coming from the ventricle, the QRS will be wide
If someone has PACs or another dysrhythmia, how would we describe their rhythm
Describe the underline rhythm, like sinus tachycardia, with PACs
What can cause PACs
- Emotional stress
- Physical fatigue
- Caffeine
- Tobacco
- Alcohol
- Hypoxia
- Electrolyte imbalances
- COPD
- Valvular disease
If someone is healthy, are we worried about isolated PACs
No, not really
When would we be worried about someone with PACs
If they have heart disease, because it may be a warning sign of a more serious dysrhythmia like a-fib
What might PACs feel like
- Palpitations
- Heart “skips a beat”
(shouldn’t have dramatic symptoms)
What might PACs feel like
- Palpitations
- Heart “skips a beat”
What are tx options for PACs
- Get off caffeine
- Beta blockers
- Monitor for more serious dysrhythmias
What does paroxysmal supraventricular tachycardia mean
- Paroxysmal = abrupt onset and termination
- Supraventricular = occurs above the ventricles (bund of His)
What will a PSVT look like
- Rate 150-220
- Regular
- Sometimes you can’t even see your P waves because it’s going so fast
- QRS narrow
- Has an abrupt onset and end (doesn’t gradually get faster and faster, all of a sudden it’s just really fast - ie you were in 80 and now you’re in 220)
What can cause paroxysmal supraventricular tachycardia
- Overexertion
- Stress
- Deep inspiration
- Simulants
- Disease
- Digitalis toxicity
Why would we be worried about paroxysmal supraventricular tachycardia
Well a HR of 180 or greater can lead to a decreased cardiac output and stroke volume leading to hypotension, palpitations, dyspnea and angina.
If a patient is stable, what techniques can we use to help treat PSVTs
- Vagal stimulation (ie beardown, blow through a straw)
- Coughing
- IV adenosine (6mg IV push - fastest IV push ever - because its half life only lasts seconds)
- Beta blockers
- CA channel blockers
- If these do work, move to cardioversion
Would we expect to see a pause in someone’s rhythm when we give adenosine? Why?
Yes, the pause may even last 6 seconds, because we’re stopping the electricity in the heart (might have asystole)
If a patient is in paroxysmal supraventricular tachycardia rhythm and they’re unstable, what do we do
Synchronized cardioversion
How does synchronized cardioversion work
Hit sync on your cart, it will find your QRSs and puts lines above them, so that way you won’t shock them in the wrong spot of their rhythm
What does atrial flutter look like
Recurring, regular, sawtooth-shaped flutter waves, but eventually you’ll have a ventricular get through.
- Big key = it’s regular and fast (usually 75-150bpm) (Little flutter waves, and then every 4th beat, for example, you’ll have a beat get through and create a QRS complex)
- P wave = looks sawtooth-shaped
What typically causes a-flutter
Disease, like coronary artery disease, hypertension, heart failure, etc…
What is the one of the big things that we worry about with atrial flutter
A clot developing, because the blood flow is not moving out of the atrium (it’s just swirling there)
If a pt is tolerating a-flutter well, will we treat it
No, probably not (pt might just live with it)
What is our tx goal for atrial flutter
Slow the atrial response by increasing AV block
How can we treat atrial flutter
- Beta blockers, CCBs
- Anticoagulants
- Cardioversion if unstable
- Radiofrequency ablation
What is a-fibrillation
Total disorganization of atrial electrical activity due to multiple ectopic foci (basically firing everywhere), resulting in an ineffective contraction
What is the most common dysrhythmia
A-fib, prevalence increases with age
How can we tell if someone is in a-fib on their ECG
The rhythm is irregularly irregular (a bunch of random looking little p waves, and then random QRSs
What can cause atrial fibrillation
*Caused by a disease (not by taking a med or caffeine, etc)
- Valvular heart disease
- HTN
- CAD, acute MI
- Cardiomyopathy
- HF
- *Pericarditis - big risk for developing a-fib
- Obesity
- Hyperthyroidism
- Cardiac surgery (Common after a CABG)
- ETOH
What can a-fib lead too
- Decrease in cardiac output
- Increased risk of stroke
- Increase risk of rapid ventricular response (going into tachycardia)
What are the different classifications of a-fib
Recurrent- 2 or more episodes
Paroxysmal- terminates spontaneously
Persistent- sustained greater than 7 days
Permanent- lasts longer than 1 year
Lone AF young adults with no causative reason
What are our tx goals for atrial fibrillation
- Decrease ventricular rate to less than 100
- Prevent embolic stroke using an anticoagulation
What drugs can we give to help stop atrial fibrillation
- *Calcium channel blockers
- *Beta blockers
- Amiodarone
- Digoxin
What is interesting about amiodarone
It has a long half life, 40-55 days, which means that it’s going to stay in your system for a long time, so really make sure that you want to give it.
What txs can we do to help treat atrial fib
- Pacemakers
- Cardioversion if unstable
- AV ablation possibility
- Long-term anticoagulation if in chronic a-fib
What is the big thing with a-fib and cardioversion
*They don’t want you to throw a clot if they cardiovert you
- So if they know that you have been in a-fib more than 48 hours or if they don’t know when your a-fib started, the n they won’t cardiovert you until you have been on anticoagulants for 3-4 weeks
What tool can they use for anticoagulant decision making
CHAD-SVASC score
What are our different anticoagulants, and what are the benefits
- Coumadin: cheap, can be reversed easily, can spike blood levels, have to have INRs drawn (vitamin k is the antidote)
- ASA
- Novel oral anticoagulants (dabigatran (Pradaxa), apixaban (Eliquis), rivaroxaban (Xarelto)): no INR testing, keep blood levels smooth, expensive
What interval are we looking at with heart blocks
The PR interval
Is a first-degree a big deal
No not usually, people tolerate these pretty well, can live their whole lives with these.
What can cause first-degree AV blocks
- MI
- CAD
- Rheumatic fever
- Hyperthyroidism
- Vagal stimulation
- Drugs: Digoxin, β-adrenergic blockers, calcium channel blockers, flecainide
What does first-degree AV blook look like
They have a long PR interval (greater than 0.2)
What are the 2 different types of second degree AV blocks type 1
- Mobitz 1
- Wenckebach
What is happening in a second degree AV block
- The PR interval gets longer and longer, and then the QRS complex is blocked (you won’t have a QRS complex (you’ll have a missed ventricular contraction)
Are we worried about second degree type 1?
Yes and no, usually people are fine, but it can progress into a type 2 or type 3.
How do we treat a second degree type 1 if the patient is symptomatic or asymptomatic?
- Asymptomatic: just observe
- Symptomatic: treat with atropine or pacemaker
What can cause a second degree AV block type 2
- Heart disease
- Drug toxicity
Why are we worried about a second degree AV block type 2
It is often progressive and can result in a decreased cardiac output
How do we treat a second degree AV block type 2
Pacemaker
What is the difference between a type 1 and a type 2 second degree AV block
In type 1 we will see the PR interval progressively get longer and longer, while in type 2 the PR interval is the same
What is happening in a third degree AV heart block (complete block)
The atrium and ventricles are not coordinated at all. There are random p waves and random QRSs (they are firing at different rates and not talking to each other) (rhythm is very slow)
What can a third degree block lead too
- Decreased cardiac output
- Ischemia
- HF
- Shock
- Syncope
How do we treat a third-degree AV heart block
With pacemaker
What is a big way to tell if someone is having PVCs
They have wide QRSs and no P waves
How can we tell if someone is having premature ventricular contractions (PVCs) based on the ECG
We will find a premature, wide, crazy big looking QRS and no P waves (because they’re coming from the ventricles
What is causing a PVCs
A contraction is originating in ectopic focus in the ventricles
What is important to remember about PVCs?
We get really worried when PVCs start going together in a row, because it can lead to ventricular tachycardia
What can cause PVCs (probably don’t need to know)
Anything that can increase the workload on the heart
- Exercise
- Fever
- Hypervolemia
- HF
- Tachycardia
- Caffeine
- Stress
- Pain
Do PVCs cause a pulse
No, not usually (this is why we can feel/hear a pulse difference when listening to the apical pulse and feeling the radial pulse)
After what procedure do we commonly see PVCs
After someone has had an angiogram or stent placement and the coronary artery is getting perfused again
What is the tx for PVCs
- Oxygen
- Fix electrolytes
- Drugs: beta blockers, procainamide, amiodarone, lidocaine
What is ventricular tachycardia V-tach
Run of three or more PVCs and the ventricles take over
Can someone live with V-tach
No, not for very long - it’s life-threatening and they will not live very long in this rhythm
What is a good way to remember what v-tach looks like
It looks like tombstones (very wide QRS - can’t really see any other waves)
What can cause v-tach
- Long QT syndrome (big one)
- Electrolyte imbalances
- Heart disease
- Drug toxicity
- CNS disorders
What can sustained v-tach cause
Severe decrease in cardiac output, which can lead to:
- hypotension
- pulmonary edema
- decreased cerebral blood flow
- cardiopulmonary arrest
What rhythm are we worried about our patient’s going into if they have v-tach
V-fib
What can cause v-tach
- MIs
- Electrolyte imbalances
- Digoxin toxicity
- Stimulants like caffeine and meth
How do we treat v-tach if the pt is stable
- Antidysrhythmic, like amiodarone
- Cardioversion
Will a pt have a pulse with v-fib
No
What does v-fib look like
Basically you can’t tell anything from the ECG, it just looks like little irregular waves
Why is it important to catch someone in v-fib
It’s the last shockable rhythm before they go into asystole
What does a person in v-fib look like
- No pulse
- No BP
- No respirations
- Unconscious
- Pretty much dead
Do we do cardioversion or defibrillation with v-fib
Defibrillation, because they don’t have a pulse
What big things can cause v-fib 2
- When someone gets shocked
- Coronary reperfusion after fibrinolytic therapy
Will asystole always look like a flatline
No, not always. It may have a little bit of movements
Is there any electrical activity in asystole
No - there isn’t anything going on
What is the rule when determining if someone is in asystole
They have to be in asystole in more than one lead
Can you defibrillate someone in asystole
No - because there isn’t any electrical activity going on in the heart
What is our tx for asystole
- CPR
- Epinephrine
- Treat the underlying cause
No matter the rhythm, if someone doesn’t have a pulse, what are we doing
CPR
What is happening in pulseless electrical activity
You have a rhythm (can be anything) on the ECG, but you’re not getting a pulse
What mnemonic can we use to think about what is causing someone to go into cardiac arrest
Hs and Ts (what is causing the problem and how can we reverse it)
Hypovolemia
Hypoxia
Hydrogen ion (acidosis)
Hyper-/hypokalemia
Hypoglycemia
Hypothermia
Toxins
Tamponade (cardiac)
Thrombosis (MI and pulmonary)
Tension pneumothorax
Trauma
What is the treatment for pulseless electrical activity
- CPR
- Intubation
- Epi
- Fix the underlying cause
What is the issue with peripheral artery disease (PAD)
Their arteries are pretty far occluded before they start having symptoms (so it’s difficult to catch early)
What causes most sudden cardiac deaths
Ventricular dysrhythmias like v-tach and v-fib
What is prodysrhythmia
Where antidysrhythmic drug can actually cause life-threatening dysrhythmias (so they are given to try and treat dysrhythmias, but end up causing them)
What two rhythms do we use defibrillation on
- V-fib
- V-tach
Do we do defibrillation for a pulseless electrical activity rhythm
No - start CPR and fix the underlying cause
When is defibrillation most effective
Within 2 minutes of dysrhythmia onset
What is happening in defibrillation
You’re sending an electrical shock through the heart to depolarize the cells, and hopefully help the AS node resume the pacemaker role
What 4 things should I remember about synchronized cardioversion
- Done on a pt with a pulse
- Synchronizer switch must be on
- There should be little lines above the R wave
- It will shock on the R wave
Can a pt have a combination of a defibrillator and a pacemaker
Yes - important to know what kind they have
Why would a pt get a defibrillator in
Have survived SCD
Have spontaneous sustained VT
Have syncope with inducible ventricular tachycardia/fibrillation during EPS
Are at high risk for future life-threatening dysrhythmias
If someone’s defibrillator is shocking them more than once, what should they do
Call 911 because the could be in a lethal dysrhythmia
What are pacemakers used for
To pace the heart when the normal conduction pathway is damaged
What do we want to see after a pacemaker spike
We want to see something, like a QRS, so we know that it’s doing something
How do pacemakers work
- They can pace either the atrium, ventricle and/or both
- They can start working with a HR drops below a preset rate
What is cardiac resynchronization therapy
Where they have a pacemaker that is pacing both ventricles, which is called biventricular pacing. It’s used to treat pts with HF
What are big complications that we should watch for with pacemakers
- Infection
- Hematoma formation
- *Pneumothorax (puncturing a lung)
- Atrial or ventricular septum perforation
- Lead misplacement
What should you teach your pt to avoid if they have a pacemaker, because these things can either deactivate the pacemaker or rip the pacemaker out with a magnet
Power-generating equipment
Welding equipment
Anti-theft stuff
Certain pieces of equipment used by dentists
Magnetic resonance imaging (MRI) machines
Radiation machines for treating cancer
Heavy equipment or motors that have powerful magnets
What is our pt teaching for pacemakers
Follow-up appointments for pacemaker function checks
Incision care (keep incision dry for 4 days - report signs of infection)
Arm restrictions (don’t raise arm on pacemaker side above shoulder until approved by your cardiologist)
Avoid direct blows
Avoid high-output generator
No MRIs unless pacer approved
Microwaves are OK
Avoid anti theft devices
Travel not restricted
Monitor pulse
Pacemaker ID card
Medic Alert ID
What are indications for pacemakers
Pretty much anything
- AV blocks
- A-fib
- Bundle branch blocks
- Cardiomyopathy
- HF
- SA node dysfunction
- Tachydysrhythmias, like v-tach
What is radiofrequency catheter ablation therapy
They can go into an ectopic area of the heart that is causing an issue and “burn” or ablate that area so it hopefully stops causing problems
What are noncardiovascular causes of syncopeobably not super important)
Stress
Hypoglycemia
Dehydration
Stroke
Seizure
What are cardiovascular causes of syncope (probably not super important)
Cardioneurogenic or “vasovagal” syncope (Carotid sinus sensitivity)
Dysrhythmias (tachycardias, bradycardias)
Prosthetic valve malfunction
Pulmonary emboli
HF
What are the 3 layers of the heart, starting with the inner most layer
- Endocardium
- Myocardium (muscle)
- Pericardium (also has the pericardial space with 10-15mLs)
What is infective endocarditis 2
- Disease of the endocardial layer of the heart
- Most often affects the aortic and mitral valves
How is infective endocarditis classified
- Cause (like from IV drug use, fungal, etc)
- Plus the site of involvement (like a valve)
What is the difference between subacute and acute infective endocarditis
- Subacute: when there is a preexisting valve disease
- Acute: when the valves are healthy
What 3 organisms can cause infective endocarditis
- Bacterial (most common)
- Viruses
- Fungi
What is the issue with bacterial caused infective endocarditis
These bacteria make biofilms, which can make it hard for us to kill
What are risk factors for infective endocarditis
- Aging
- IV drug use
- Prosthetic valves
- MRSA in your blood
- Hemodialysis
What are the 3 stages of infective endocarditis
- Bacteremia (bacteria floating around in the heart)
- Adhesion (adhere to heart valves)
- Vegetation (start growing - create biofilms)
What is a big risk with infective endocarditis
Things can get stuck in these biofilms like fibrin, leukocytes, platelets and microbes, and create clots, which can break off and cause a stroke
(30% of people develop embolization)
What are the nonspecific symptoms of infective endocarditis
- Fever
- Chills
- Weakness
- Malaise
- Fatigue
- Anorexia
What are subacute symptoms of infective endocarditis
- Arthralgias
- Myalgias
- Back pain
- Abdominal discomfort
- Weight loss
- Headache
- Clubbing
What are vascular symptoms of infective endocarditis
- Splinter hemorrhages in the nail beds (look like little splinters)
- Petechiae
- Osler’s nodes on fingertips or toes (red and painful lesions)
- Janeway’s lesions on pads of the fingers and toes (not painful)
- Roth’s spots
If someone has infective endocarditis, what might we hear when listening to the heart
Murmur
Besides a risk for an embolism, what is another complication caused by infective endocarditis
HF
How do we diagnosis infective endocarditis
- History is SUPER important (anything that can introduce bacteria into the blood)
- Labs: *blood cultures (from 3 different sites), CBC with diff (look at WBCs) , ESR and c-reactive protein (see if there’s inflammation)
- *Echo (look at the valves to find vegetation/disfunction)
- Chest x-ray
- ECG
- Duke criteria
If someone is at risk for infective endocarditis, what should they do before having a procedure done (think of Kaleb and the dentist)
Need to be on prophylactic antibiotics before having tx
What is our tx for someone with infective endocarditis 7
- Long-term IV antibiotics (4-6 weeks)
- Repeat blood cultures to see if the antibiotics are working
- Valve replacement if needed
- Follow up echo and inflammatory markers (1, 3, 6, 12 months)
- Antipyretics (acetaminophen)
- Fluids
- Res
What type of infection is a big risk for infective endocarditis
Staph or strep
What is some nursing care for someone with infective endocarditis 2
- Moderate activity (don’t want to cause chest pain while they’re fighting the infection)
- Deep breath and cough every 2 hours
What is happening in myocarditis
There is inflammation going on
What things can cause myocarditis 6
- Viruses
- Bacteria
- Fungi
- Radiation
- Pharmacological factors
- Chemical factors
- Autoimmune
- Idiopathic
What can myocarditis lead too
- Cellular damage
- Necrosis
- Cardiomyopathy
What is interesting about the symptoms of myocarditis
The symptoms can range from benign to life threatening symptoms like HF, dysrhythmias or sudden cardiac death
What are symptoms of myocarditis
- Fever
- Fatigue
- Malaise
- Myalgias
- Pharyngitis
- Dyspnea
- Lymphadenopathy (swollen lymph nodes)
- N/V (early symptom of viral illness)
- Cardiac symptoms usually 7-10 days after viral illness
- Pericarditis
What are early and late symptoms of pericarditis
Early: pleuritic chest pain, pericardial friction rub, effusion
Late: HF symptoms - s3 heart sounds, crackles, JVD, syncope, peripheral edema, and angina