Dysrhythmias 1, 2, and 3 Flashcards
How to differ a sinus arrhythmia from AFIB
Breathing in will increase the HR
Breathing out will decrease the HR
What is considered sinus bradycardia?
<60 BPM
really only worried if it is <45 BPM though
What can lead to sinus bradycardia?
Normal in healthy individuals
Should go up if they exert themselves
What if sinus bradycardia does not increase with exertion?
Sick sinus bradycardia
What drug can cause bradycardia?
Clonidine - lowers BP but decreases HR
lithium
methyldopa
Why can a stroke lead to bradycardia?
To compensate for increased ICP, the heart will pump softer
Scan the HEAD!
Why can an inferior wall MI cause bradycardia?
Problems of right coronary artery, which supplies the SA node, leads to a decreased HR
What is the treatment for obstructive sleep apnea bradycardia?
Treat the OSA!
CPAP
Don’t treat the bradycardia - it is just a result of the underlying cause, which is the OSA
How to diagnose sinus bradycardia sick sinus syndrome?
Put on treadmill and DO NOT see something close to predicted value (220 - age)
How to treat sick sinus syndrome?
Remove medications to see if this is the underlying cause of their bradycardia (do not remove amiodarone though). Otherwise:
Pacemaker - there HR will fluctuate like crazy, so you can more easily decrease an elevated HR
When do you treat sinus bradycardia?
If they are symptomatic
What shortens in sinus tach?
The T wave to the next Q wave
What underlying things can lead to sinus tachy?
hyperthyroidism, fever, sepsis, pain, anemia, volume depletion, pheochromocytoma, hypoxia, PE, heart failure, acute coronary ischemia, alcohol/alcohol withdrawal, stimulants
How do you treat sinus tachy?
RARELY
If they are in sinus tach, they are there for a reason
What can you do to try to slow down sinus tach?
Vagal maneuvers
even deep breathing
If no fluctuation, it is not sinus!!!
When is sinus tach a concern?
If there is an underlying heart problem
Where do we make up time for sinus tach?
Diastolic shortens, so we get less filling.
We still have the same systolic pump, but filling/relaxation may be compromised
When is sinus tach concerning?
If it is symptomatic and they have an underlying heart problem
What leads to inappropriate sinus tach?
Occurs in absence of heart disease or secondary causes
_ resting HR and/or exaggerated HR response to exercise
Exact cause unknown; possible exaggerated autonomic control
Difference between inappropriate sinus tachy and POTS
POTS is based on change in position while inappropriate sinus tach is based on things that would normally lead to increased HR, but it is an exaggerated response (may increase 2x compared to a normal, healthy patient).
Three different heart blocks
1st degree = PR interval greater than 0.2 seconds
2nd degree = sometimes it goes through
3rd degree = complete heart block; complete A-V dissociation, in which no supraventricular impulses are conducted to the ventricles
What causes first-degree heart block and Mobitz type 1?
May occur in normal individuals with heightened vagal tone
Drug effect - especially digitalis, calcium channel blockers, beta-blockers, or other sympatholytic agents
Electrolyte abnormalities
Organic disease - ischemia, infarction, inflammatory processes (including Lyme disease), fibrosis, calcification, or infiltration
May be transient or chronic
What can lead to a mobitz type II and third degree heartblock?
Almost always due to organic disease involving the infranodal conduction system
May be transient or permanent
What can be a normal heart block? What is not normal?
The first two heart blocks can be normal:
1st degree heart block and Mobitz type 1
The last 2 are almost ALWAYS pathologic:
Mobitz type 2 and type 3 heart block
What is a more exhaustive list of mobitz type II and III block?
ischemia
idiopathic
neuromuscular diseases
trauma
aortic valve problems/infections/surgery
Get an echo
What are the s/s of 1st degree AV block?
No symptoms, cannot hear on stethescope because everything goes through
just incidental on EKG
Mobitz type 1 s/s
Most commonly asymptomatic; however, may note palpitations, DOE, or dizziness
Mobitz type 2 s/s
Mainly exertional symptoms
palpitations, DOE, weakness, or dizziness
Third-degree block s/s
Symptoms vary, and are worse with exertion; palpitations, DOE, weakness, near syncope, syncope, and/or heart failure
Physical exam findings include bradycardia and possibly signs of heart failure
What are the diagnostic studies for heart blocks?
ECHOOOOOOOO
EKG
Ischemic, go to heart cath or CTA
What can we not do for heart block patients that is a common work block?
Exercise and chemical stress test
What labs do ALL heart block patients get?
Labs: CBC, CMP, TSH
Management of First degree AV block?
Nothing, just avoid PR prolongation medications
Management of mobitz type I?
Nothing, just avoid PR prolongation medications
Mobitz Type II and Third-degree AV Blocks
Unstable rhythms and majority require permanent pacemaker implantation
However, if transient due to acute organic process, then temporary pacing may be sufficient
If you have symptoms for premature atrial contractions, do you treat?
None!
BB if significant
Premature ventricular contraction - are they concerning? What should patients do?
Normally in normal hearts (60-80% of the time)
-concerning if EXERTIONAL - normal if they rest and lay down at night
should keep a log of when they notice them
What can cause premature ventricular contraction
Caffeine, stress, alcohol
Structural heart disease – CAD, Valvular disease, LVH
Electrolyte abnormalities
Thyroid disease
What electrolyte should we order in addition to BMP?
Mg levels - not included
go hand and hand with K+
What are the s/s of premature ventricular contractions?
reentry circuit
Typically initiated by a PAC or PVC
What is the MC pathophys of supraventricular contractions
reentry circuit
Typically initiated by a PAC or PVC
What are the two reentry types that lead to supraventricular
AVNRT (AV nodal reentrant tachycardia) – most common form
AVRT (AV reciprocating tachycardia)
WPW – Accessory pathway
fast pathway
short green light, long red light
MC form of SVT reentry
AVNRT
When is a reentry a problem?
When there is a PAC, which can lead to a circuit
how to tell the difference between WPW and AVNRT
need resting EKG to show delta waves on Wolff-parkinsons
what is the clinical presentation of SVT
Rapid onset and offset of rapid heart rate and awareness of symptoms
patient management of SVT
Valsalva (push down on abdomen with crossed fingers around the umbilical and have patient press abdomen against fingers for 5-10 seconds PREFERRED)
Stretching the arms and body, lowering the head between the knees
Coughing, breath holding
Splashing cold water on the face, placing ice or frozen peas on the face
All to increase intrathoracic pressure
What can be done by a provider to reduce symptoms of SVT?
Carotid sinus massage – SHOULD ONLY BE DONE BY A PROVIDER
-firm pressure, deep tissue, for 5-10 seconds
much more intense vagal response
ONE CAROTID AT A TIME
need telemetry and crash cart
What is the first line pharm treatment for acute SVT
Adenosine
What are some other pharm treatment of acute SVT?
CCB – Diltiazem, Verapamil
Beta-Blocker – Esmolol, Lopressor
What is used for refractory SVT
Amiodarone
Procainamide (anti-dromic wide complex tach)
What is the first-line treatment of hemodynamically unstable tach
SHOCK (Synchronized electrical cardioversion)
if hypotensive
First-line treatment of long-term SVT
catheter ablation
First line therapy for recurrent, symptomatic PSVT
curative
can cause complete heart block if they ablate too much
First-line meds if not a surgical candidate for SVT
BB or CCB
when do you refer to EP for SVT?
WPW -should go to cath lab
What can lead to ectopic atrial arrythmias?
Results from an ectopic atrial focus creates an action potential at a rate faster than the sinus rate, therefore becoming the pacemaker
Onset and termination occur abruptly
P wave morphology varies from sinus node P wave
Atrial rate can range between 50 and 180 bpm
Most commonly between 100 to 160 bpm – Atrial Tachycardia
May be unifocal or multifocal
How to tell if something is atrial tach?
Everything normal, except abnormal p waves and tachy
What can cause ectopic atrial rhythm?
Mostly normal
-2-6%
get an ECHO!
What are some electrolyte disturbances that can lead to atrial tach
Electrolyte disturbances (especially hypokalemia), chronic lung disease or pulmonary infection, acutealcoholingestion, hypoxia, and use of cardiac stimulants (theophylline,cocaine)
treatment of atrial tach
only symptoms
BBs and CCB first-line
then EP
what likely causes atrial fib?
Likely left atrium, but don’t know
left atrium fire around the same time, fire off at 350-400, go to AV node or accessory pathways
leads to irregularly irregular rhythm
What are the different phases of afib?
Paroxysmal (<48 hours) - normally short-lived. MC
Persistent - short burst do not fix themselves >7 days - we need to convert them to sinus (patients that do not seek treatment) success rates to maintain sinus decrease if you get to this stage
Long-standing persistent >1 year
Permanent: livable rhythm (majority of patients get here) - if you live long enough
Is there a cure to Afib?
NO
all patients will have permanent afib
what is the goal of treatment of paroxysmal vs permanent afib
paroxysmal = we want to keep them in sinus
permanent = we want to manage symptoms
What are the risk factors for afib?
CHF
HTN
Advanced age
CAD
Valvular heart disease (can affect that component of the heart)
because these risk factors are so common, afib is so common
What is a very common underlying cause of afib?
OSA very common
also underlying lung problems, leading to increased heart pressure
also cardiac surgery, pericarditis, and other underlying causes
Is afib alone common?
No, typically just one episode in otherwise healthy young patients and then it goes away.
Still risk of recurrence
what are the symptoms of afib?
May be completely asymptomatic
Palpitations, heart racing sensation, SOB, chest pain, fatigue, dizziness, near syncope – all possible
May cause hypotension, especially if underlying heart disease and HR elevated
Persistent tachycardia may lead to cardiomyopathy
May also present due to thromboembolic event – CVA, acute limb arterial occlusion
what are the PE of afib
Irregularly irregular rhythm
May have signs of CHF
Distal pulses may be difficult to obtain, especially if vent. rate is rapid
how to tell if afib or heart failure came first?
Treat afib, if heart failure goes away, it was the problem. If the heart failure persists, then the afib came from the heart failure - not the other way around
What do you treat, the pulse or electrically what they see on the monitor for afib>
The monitor - the HR on a pulse ox may not be accurate in afib
What do you order for diagnostic studies for afub?
ECHO
BMP +Mg
TSH
What is the three-fold management of afib?
- Thromboembolic event prevention to prevent stroke, ischemic bowel, and ischemic limb
2 and 3: Rate control vs rhythm control
What is interesting about frequency of afib and mortality?
Frequency and symptoms are NOT correlated to mortality
if they feel fine in afib, you keep in afib
if they feel bad in afib, you try to convert to sinus
What are the rate control meds for afib?
CCBs
Beta blockers
Digoxin
What is the long term management of afib?
AV node ablation with pacemaker implantation
What class of drugs can you not use for heart problems?
class 1c
normal heart afib
class 1c, then
sotalol use
if you have CAD
what are our 2 meds we use for heart failure
amiodarone dofetilide
management of hemodynamically unstable afib with KNOWN afib with <48 hours
shock
what patients get shocked
CHADS2 -VASc score
Congestive HF
Hypertension
Age => 75
DM
S2 prior TIA or stroke
Vascular disease (MI, aortic plaque, etc, AAA)
Age 65-74
Sc sex category (female = 1 pt)
What chads2-vasc score is typically treated?
typically 2 or more
CHA2DS2-VASc score = 0
no treatment
CHA2DS2-VASc score = 1
recommend antithrombotic therapy with oral anticoagulation or antiplatelet therapy (ASA 81 mg) but preferably oral anticoagulation
CHA2DS2-VASc score = 2
recommend oral anticoagulation
What is the HAS-BLED used for?
To see if they would be at a higher risk of bleeding rather than stroke
If Has-bled is greater than CHADS2 VASc score, then talk to patient about whether or not they wanna be on Anti-coagulants
What is the initial anticoagulant used for afib
LMWH
Heparin
Treatment of valvular AFIB
ONLY Warfarin
this is also the only time you should use warfarin!!!!
treatment of any other AFIB
a DOAC!
Eliquis (superior)
Xarelto (not-inferior)
Pradaxa (not-inferior)
Savaysa (not-inferior)
what is the maintenance of afib
Tell patients it changes with time, no cure.
Deal with it long term
see every 6 months for drug monitoring
CBC, BMP
Avoid alcohol (cardiotoxic)
Control underlying RF
What is atrial flutter?
An ORGANIZED afib
right or left sided
saw-tooth pattern
see atrial activity
What is the ONLY difference between atrial flutter and AFIB management?
MAY be curative with ablation on it’s own
otherwise the EXACT same treatment
A 23-year-old female presents for an annual evaluation and reports no problems. On exam, cardiac rhythm is slightly irregular, with an increase in her heart rate with inspiration and a decrease during expiration. Which of the following is the recommended management for this patient?
No treatment
A 31-year-old female presents complaining of a racing heart. Electrocardiogram demonstrates a supraventricular tachycardia, likely due to AV nodal reentry. Mechanical measures fail to convert the rhythm. Which of the following medications should be initiated?
Amiodarone (Pacerone)
Adenosine
Flecainide (Tambocor)
Disopyramide (Norpace)
Lidocaine
Adenosine
which works on the AV node, first-line treatment
only time we ever use this med!!!
A 70-year-old woman is brought to the Emergency Department by ambulance because she has had nausea, shortness of breath, and diaphoresis for the past 2 hours. Medical history includes type 2 diabetes mellitus, hypertension, and hyperlipidemia. Current medications include metformin and HCTZ. Temperature is 98.7 F, pulse rate is 38 bpm, respirations are 20/min, and BP is 90/60 mmHg. Oxygen saturation is 90% on room air. The patient is alert and oriented to person only. Physical examination shows pallor, diaphoresis, and cool skin.
Which of the following diagnostics is most important to obtain initially in this patient?
Chest CT without contrast
12-lead EKG
CBC, PT, PTT
CMP
Urinalysis
12-lead EKG, because we wanna see what is coming from it
A 71-year-old male presents with fever, cough, shortness of breath and mild lethargy. Chest x-ray demonstrates an area of consolidation of the right middle lobe. Telemetry demonstrates a sinus tachycardia of 115 bpm. Which of the following is the most appropriate management of this patient’s dysrhythmia?
IV administration of metoprolol (Lopressor)
manage underlying pneumonia
IV administration of adenosine
carotid sinus massage
Manage underlying pneumonia, the HR will improve as a result
What is the typical presentation of junctional arrhythmias and treatment
stable
find reversible cause
does not require anything
what is the worst type of arrhythmia
ventricular
What are the two mechanisms of accelerated idioventricular rhythm?
(1) an escape rhythm due to suppression of higher pacemakers resulting from sinoatrial and AV block or from depressed sinus node function
(2) slow ventricular tachycardia due to increased automaticity
treatment of accelerated idioventricular rhythm?
ONLY if there is hemodynamic instability
Non-sustained V tach
less than 30 seconds, terminates spontaneously
NOT concerning
160–240 bpm
Sustained V tach
greater than 30 seconds
WORRIED
160–240 bpm
what can cause v tach
acute MI
CAD
Cardiomyopathy
What is Catecholaminergic Polymorphic VT?
you get scared, release NE, Epinephrine, and then get V tach and pass out
what should be on your differential if a kid passes out in reaction to fear or exertion?
NOT EPILEPSY
worried about congenital abnormalities
What type of PVCs are concerning?
Multifocal
Unifocal not as concerning
What most likely causes Torsades?
Prolonged QT
check drugs!
What normally causes prolonged QT?
Drug induced by far
if not, refer
What is congenital long QT syndrome?
Three different syndromes
MCC of death of long QT II
The most common forms of congenital LQTS are caused by ion channel defects.
LQT1and LQT2are K+channel abnormalities
LQT3is an Na+channel mutation.
Proposed as one of the causes of sudden infant death syndrome
Most patients have the first event around 9 to 12 years of age.
LQT1and LQT2account for 80% of the cases.
Exercise and sudden auditory stimuli are triggers
LQT3is only seen in 10% of the cases, but it accounts for most of the lethal cases of LQTS.
Most of the events occur during sleep at slower heart rates
what is brugada syndrome
RBBB with ST segment elevation that does not return to baseline
If it does not return to baseline than refer to EP (preferred) or cardiology
What is the treatment of brugada
Propranolol and Nadolol are preferred
What is the treatment of hemodynamically unstable V tach?
shock and sedation
What is the acute treatment of hemodynamically stable V tach?
IV amidodarone to convert to sinus
IV lidocaine if refractory
IV Mg possible
What is the long term treatment of V tach?
ICD
Beta blockers
Amiodarone, Sotalol (Class III AAD)
Catheter ablation
seen by EP
what is the treatment of nonsustained VTach?
Nothing if they are asymptomatic and have no underlying heart disease
BB if symptomatic
What can stable V tach lead to?
unstable V fib
leading cause of sudden death
what is the management of V fib?
SHOCK, unsynchronized
What is more concerning LBBB or RBBB and why?
LBBB, because it is often d/t underlying heart disease. Also it involves the LAD that is the primary blood supply.
still sometimes seen in normal hearts
What can lead to LBBB
LBBB is not usually the result of a single clinical entity, except in acute MIs.
Several chronic conditions which contribute to myocardial fibrosis (hypertension, coronary artery disease, cardiomyopathies) can contribute to the development of LBBB.
LBBB may result following acute myocardial insult, and if occurs is associated with worse prognosis
Functional LBBB
Rate-related aberrancy
How do you evaluate LBBB?
- Chest pain with acute ischemia = treat as if it is an anterior STEMI
- Asymptomatic with baseline EKG that has LBBB, do not send to ER but look for RF and work them up with an echo
- If they have risk factors for ischemia, then work up according to heart score
Management of LBBB
treat underlying problemo
What should be on your differential for a RBBB
lung disease etiologies
Patients with RBBB workup
Based on symptoms
not concerning
do not even need an echo
Bifasicular block management
Benign
do not need to do anything for it
When would you consider a pacemaker for bifascular bock?
Syncope w/ bifascular block
Get an echo
Get EP
otherwise no treatment
