Therapeutics - Anti Arrhythmic Drugs Flashcards
what is normal sinus rhythm?
60-100 bpm
what is the pathway of normal sinus rhythm
starts with electrical impulses generated at the SA
SA located at the right atrium
spreads to atria to AV node
travels down bundle of HIs
further spreads to bundle branches
reaches the purkinje fibers which stimulate ventricle contraction
what is an arrhythmia
an irregular heartbeat
occurs when electrical signals that control the heart rhythm do not work properly
heart beats too fast or too slow or irregular pattern (fibrillation)
p wave controls what action of the heart
activation of the atria
the qrs wave controls which action of the heart
activation of the ventricles
what does the t wave control
recovery wave, repolarization of the ventricles
Supraventricular arrhythmias occur where in the heart
above the bundle of his
where does normal sinus node originate
SA node
normal sinus rhythm transmits through the _____ to the his purkinje system
AV node
how to measure rhythm of the heart
EKG
What are the supraventricular arrhythmias
sinus brady, sinus tachy, paroxysmal supraventricular tachy, atrial flutter, atrial fib, WPW, premature atrial contractions
T or F supraventricular arrhthymias are characterized by normal QRS complexes
T
T or F ventricular arrhythmias are considered emergent and life threatening
T
What are the ventricular arrhythmias
premature ventricular contractions, ventricular tachy, ventricular fib, pulseless electrial activity, asystole
what types of conduction blocks are there
first, second, third AV block
left or right bundle branch block
sinus brady is ____ bpm
less than 60
what are some causes of sinus brady?
increased vagal tone - parasympathetic effects
inferior wall MI
medications such as beta blockers, verapamil
what are the symptoms of sinus brady?
from none to
organ hypoperfusion
hypotension, altered mental status, shock, ischemia
what is the first step to treat sinus brady?
find the causes and correct causes
what is the first line treatment of sinus brady?
atropine 1 mg IV repeat every 3-5 minutes
what is the maximum dose of atropine
3 mg
what to use for sinus brady if atropine fails?
transcutaneous pacing, dopamine and epinephrine
how many bpm is sinus tachy
greater than 100 bpm
what are the causes of sinus tachy
body attempting to maintain CO and BP, can be physiologic
medications - sympathetic (epinephrine), caffeine, nicotine, cocaine, anything blocking parasympathetic (atropine)
what are the symptoms of sinus tachy?
none to
palpitations, irregular pulse, fatigue, syncope, and other signs of organ hypo-perfusion
what is the non pharmacologic treatment for sinus tachy
vagal maneuvers - valsalva, carotid massage to decrease sympathetic tone which increases vagal tone
what is the pharmacologic treatment of sinus tachy?
adenosine is the first line of treatment
6 mg IV bolus, can repeat with 12 mg IV bolus q2 minutes
max 30 mg
glush line following bolus
what are some symptoms a patient with sinus tachy treated with adenosine may experience
chest heaviness
flushing
anxiety
wheezy or sob In asthma pts
if adenosine does not work for sinus tachy, what other drugs can be used?
beta blocker or non DHP CCB
what is seen for afib on an ekg
irregularly irregular ventricular rate with NO P WAVES
unreadable because 350 - 450 bpm
ventricular rate ranges from normal to RVR up to 160 bpm
atrial fibrillation can be paroxysmal which means it lasts _____ days
less than 7
atrial fibrillation that last more than 7 days is called
persistent afib
can afib be permanent
yes
what are some risk factors for afib?
age
smoking
sedentary
alcohol
increased weight
taller
htn
db
cvd
ckd
osa
hyperthyroidism
sepsis
more education
more income
white
male
what are the symptoms of afib
none to symptoms of tachycardia
palpitations, irregular pulse, fatigue, syncope, and other signs of organ hypo-perfusion
how can afib be managed?
reduce stroke risk
optimize risk factors
symptom management to control rhythm and rate
what are the different risk factors and what are the reccomendations for management
overweight - loss greater than 10%
inactive -210 minutes per week of moderate to vigorous
smoke cigarettes - quit
alcohol - minimize or eliminate
caffeine - only as needed to avoid triggers
HTN - reach BP goals
what are the randomized controlled trials comparing rate control versus rhythm control
AFFIRM, RACE, AF CHF
all the patients in AFFIRM, RACE, AF CHF received
oral antioagulation
what were the results of AFFIRM
overall mortality and strokes equivalent, less hospitalizations and AE with rate control
what were the results of the RACE study
cardiovascular death and morbidity equivalent
what were the results of the AF CHF
cardiovascular death equivalent
what did the EAST ADNET4 study reveal
early rhytm control led to fewer composite outcomes
what are the goals of rate control?
to reduce symptoms and have resting HR between 100-110 bpm
what are the pharmacologic options for rate control?
beta blockers
calcium channel blockers
digoxin
why are beta blockers a good option for rate control>
inexpensive and generic
what is the loading dose and maintenance dose of metroprolol for rate control for afib?
loading dose - 5 mg IV over 5 minutes for acute rate control
maintenance - 25-100 mg po bid
when are beta blockers controindicated?
in 2nd or 3rd degree heart block, sick sinus syndrome and severe bradycardia
in which pts should beta blockers be avoided
if the pt has an hyperactive airway, hypoglycemia in db pts
what are the only kind of calcium channel blockers can be used to control rate
nondihydropyridines - many formulations
what is the loading and maintenance dose of diltiazem for control rate in afib patients
loading dose - 0.25 mg/kg IV over 2 minutes, repeat 0.35 mg/kg in 15 mins, then 5-15 mg/hr IV infusion for acute
maintenance dose 60-90 mg tid or 4x day po for long acting
what is the loading and maintenance dose for control rate for afib using verapamil
loading dose - 5-10 mg IV ocer 2 minutes, can repeat 10 mg in 15-30 m then 5-10 mg/hr IV for acute
maintenance 40-120 mg tid po for long acting
calcium channel blockers should be avoided in
HFrEF
what kind of DDI should we be aware of for calcium channel blockers
CYP450 and CYP3A4
afib rate controlled with digoxin needs adjustment for ___ impaired patients
renally
which is more effective digoxin or BB/CCBs
BB/CCBs
what is the po dosage for digoxin
125 or 250 mcg tablets
what is the iv dosage of digoxin
100 mcg/ml
What are some drug interactions that one should be aware of when administering digoxin?
verapamil
quinidine
propafenone
flecainide
amiodarone
pgq inhibitors
what is the goal of rhythm control?
to reach nsm and reduce symptoms
what is acute transition to NSR called
cardioversion
how can one treat rhythm control “cardioversion”
medications like ibutilide, amiodarone, flecainide, propafenone “pill in the pocket?
or can do electrical cardioversion
how to maintain rhythm of atrial fib?
dofetilide, dronedarone, flecainide, propafenone, amiodarone, sotalol
limited by comorbidities such as MI, HF or structural heart disease
if a pt needs to maintain afib rhythm, but has HF, MI or other structural heart disease, what medication can they take?
sotalol
amiodarone
When should we choose to control rhythm in afib pts
if atrial fibrillation is less than a year, and if HF symptoms persist on rate control, hemo instability
short duration, concurrent HF, persistent symptoms, hemodynamically unstable
what variables impact whether we control rate or rhythm for afib>
patient choice
age
antecedent history of af
symptom burden
rate control in af
la size
lv function in af
av regurgitation in af
if the patient is younger, what is preferred, rate or rhythm control?
rhythm
patients with a longer history of afib, should control their
rate
patients with more symptoms, treatment of afib faors
rhythm control
what is the daily dose of flecainide for rhythm control
200-300 mg po daily
what is the daily dose of propafenone for rhythm control
450-900 mg daily
what is the dosage of flecainide and propafenone?
prn , one dose
for flecainide or propafenone, a ____ agent is necessary
AV nodal blocking agent
what is the daily dose of sotalol for rhythm control in pts with afib
150-320 mg daily
what are the monitoring parameters of sotalol
monitor EKG - QTC interval for initial 3 days then 3-6 months
in what pts is sotalol contraindicated in
ClCr less than 40 ml/min
which drug is most effective in rhythm control in afib patients
amiodarone is highly effective
amiodarone is highly effective but why is it reserved only for patients who failed other therapies
because it has multiple toxicities
what is the half life of amiodarone
58 days - 15-143
T or F amiodarone has large volume distribution
T
what are the DDI of amiodarone
it inhibits CYP 1A2, 2D6, 2C9, 3A4, PGP
what is the loading dose of amiodarone
6-10 mg total
what is the maintenance dose of amiodarone
200 mg per day
what are the monitoring reccomendations for amiodarone
baseline - cxr, alt/ast, tsh, ekg
repeat every 6 months : tsh, alt/ast
repeat every year - ekg, physical (for skin and neuropathy)
others as clinicaly indicated - CXR, CT, opthalmic
what are drug that prolong the QTc interval and risk for torsades de pointes
type I and III antiarrhythmias
azithromycin
chlorpromazine and thioridiazine
citalopram
clarithromycin and erythromycin
haloperidol
methadone
what are the ADR of amiodarone
hypo and hyper thyroidism
hepatotoxicity
qt interval prolongation
interstitial lung disease
corneal microdepsots
blue gray skin - photosensitivity
neurological
what is the daily dose for dofetilide
500 mcg
does dofetilide need to be dose adjusted
yes for renal dysfunction
dofetilide is contraindicated in patients with
ClCr less than 20 ml/min
what are the risks of dofetilide
serious ventricular arrythmias
when should dofetilide be administered
initiate while inpatients x3 days
qtc prolonging risk
then EKG 3-6 months
what is the daily dose for dronedarone
400 mg bid
what are the benefits of dronedarone over amiodarone
has a shorter half life
there is no iodine
and less noncardiac toxicities
is dronedarone more or less effective than amiodarone
less effective
dronedarone is CI in pts
with permanent AF
NHYA class 2-3 with recent composition
NHYA class 4
dronedarone has an FDA warning for
hepatotoxicity
what causes cardiac emergencies
pulseless VT, VF, PEA, and asystole
extra ventricular systolic beat characterizes
PVC
what characterizes ventricular tachy
greater than 3 PVCs + HR greater than 100
TdP is characterized by
hall mark of long QTc
PEA is characterized by
organized electrical activity
flatline is also known as
asystole
T or F vtach can be with or without a pulse
T
if there is a pulse during Vtach this means that there is ____ happening
perfusion
TdP can be due to
congenital long QT syndrome but more likely drugs
by definition ventricular fibrillation is considered
hemodynamically unstable
key characteristic of VF on ECG is
no clear QRS complexes
a lack of pulse, cardiac output and blood pressure of VF can lead to
sudden cardiac death
what are the components of basic life support
basic recognition of SCA and activation of emergent responses
early performance of high quality CPR - CAB , hand only
rapid defibrillation for VF , pulseless VT only
what does ACLS stand for
advanced cardiac life support
defibrillation is only for
pulseless VT and VF
what ACLS intervention outcomes improve survival to hospital discharge
high quality CPR
defibrillation when appropriate
what ACLS intervention outcomes improve the return of spontaneous circulation but DO NOT improve survival to discharge
IV access placement, drug deliery, advanced airway placement
what are the treatable causes of sudden cardiac arrest
Hypoxia
hypovolemia
hydrogen ions - acidosis
hypo hyper kalemia
hypothermia
toxins
tamponade
tension pneumo
thrombosis pulm and coronary
what are the ACLS medications
epinephrine 1 mg IV/ IO every 3-5 m
amiodarone 300 mg IV IO once when defib x3 fails and epinephrine x1
vasopressin 40 units not recc
ventillation is
2 breaths per 30 s or 1 breath / 8 seconds if bag valve mask ambu bag self inflating bag
