AF VTE Flashcards
non-dihydropyridine CCBs prescribed for
rate control, prescribed for AF not for HF
Verapamil selective for myocardium – reduce myocardium oxygen demand and act on coronary vasospasm to treat arrhythmia and angina
b. Diltiazem –cardiac depressant and vasodilator, decrease arterial pressure with little of the cardiac stimulation by dihydropyridines
c. Both for AF to improve QOL and exercise tolerance
d. Both avoid in patients with HF due to negative inotropic affects, edema AE
p-value
0.05 less than
function of BB
slow heart rate
Block catecholamines (fight-flight hormones) released by adrenal gland responsible for increasing heart rate and narrowing vasculature
b. Slowing heart rate, acting as vasodilators to widen vessels and allowing the heart to receive more blood and oxygen
c. Often prescribed for HTN, CHD, post-MI, AF
d. Stimulate muscles to constrict air passages (B2) – thus avoid in pts with asthma or bronchospasmic conditions
e. Mask symptoms of hypoglycemia thus avoid in pts with diabetes
normal heart rate
Resting 60 to 100 beats per minute
effect of age on heart rate (specifically on the heart walls thickening and blood vessels stiffening)
As aging progresses: the heart’s walls thicken, decreasing the heart rate both at rest and during activity
embolus
moving thrombus
a. Anything (fat, air, or clot) that journeys through blood vessels until it reaches one that is too small to let it through
b. The medical problem is brings on is called an embolism
c. Thromboembolism refers to a small piece of thrombus that breaks free to roams the circulatory system
ion channels
a. Voltage gated channels that allow ions to pass through (in and out) of the cell for polarization
b. Depolarization: calcium channels allow for influx of calcium ions into cell
c. Repolarization: potassium leaves the cell at resting state
what happens when an electrical impluse re-enters the cardiac muscle
AF
arrhythmia
(Chaotic cycle lead to reentry, circus movement)
causes of AFib
sleep apnea, HTN, MI
are cardiomyopathies structural or functional
functional
sensitivity of lab testing
accuracy of the probability of a positive test given that the patient has disease;
define specificity
probability of a negative test given that the patient is normal; higher the specificity, the fewer normal
people are misdiagnosed as having the disease.
can atrial fib occur in patients with structurally normal hearts
Yes; Individuals with
structurally normal hearts can develop AF, as evidenced by lone AF patients, or the
disease may develop in relation to various CV and other diseases.
mean and median
mean - average
median - middle
AF Paradox
lower incidence of AF with Blacks, an indication that we’re just not able to
ascertain AF as well in certain racial and ethnic groups. Perhaps blacks would have higher rates of AF if more sensitive AF detection methods are used.
normal LVEF
LVEF 50% to 70% is considered
normal.
Coagulation Cascade
either intrinsic: contact activation pathway involving Factors XII, XI, IX, VIII, V,
or extrinsic: tissue factor pathway involving Factor VII
the two pathways converge to produce thrombin
what effect do statins have on AFib
inconclusive
maze surgical incision patterns
curly H
Maze” refers to the series of incisions arranged in a maze-like pattern in the atria
Surgical Ablation
The first open-heart surgical ablation technique for AF – and still the gold standard –
was the Maze procedure, developed in 1987 by James Cox and associates. Also called
the Cox Maze procedure, this cut-and-sew technique was found to effectively restore
sinus rhythm and atrial contraction in patients with intermittent or chronic AF.;
hemorrhagic stroke
occurs when a blood vessel bursts inside the brain
mechanism of warfarin
Vitamin K antagonist;
posterior
directed toward or situated at the back; opposite of anterior
bradycardia
slow heart rate, less than 60 beats per minute
calculation of INR
INR = (PTpatient/PTnormal)^ISI
potassium release from heart cells associated with (calcium produces heart contraction)
repolarization to resting state
what causes more hospitalizations for stroke: Afib or HTN
HTN
demographic trend for the population of patients with Afib
increasing
incidence
Incidence refers to the frequency an illness develops in a population during a specific
period of time, normally 1 year.
SA Node
pacemaker of the heart
ECG
(ECG) This test records the heart’s electrical activity. It can
measure the rate and regularity of heartbeats, the size and position of the chambers,
the presence of any damage to the heart, and the effects of drugs or devices used to
regulate the heart (such as a pacemaker). Typically 12 to 15 electrodes are strapped to
the patient’s chest for a diagnostic ECG. Also called an EKG.
electrical depolarization
depolarization. Depolarization opens calcium channels allowing an influx of
calcium, QRS segment, ventricular contraction,
QTc
adjusted for heart rate; electrical depolarization and repolarization of the ventricles; corresponds to the time during which the lower
ventricles are triggered to contract and then build the potential to contract again; in other
words, a rough estimate of the length of an average “ventricular action potential”.
upper chambers of the heart
atria
function of pulmonary arteries
carry deoxygenated blood away from the heart to the lungs; only artery that carries ‘blue blood’
what can lead to deadly arrhythmias
wide QT interval, VTach
anterior
nearer the front, esp. situated in the front
AV node
located between the atria and the ventricles (B). Here, the signal slows down
slightly, allowing the ventricles time to finish filling with blood.;
chambers of the heart
looking at the heart: right atrium —- left atrium
tric valv septum mitral valve
right ventricle left ventricle
causes of stroke associated with AFib
thromoembolism
most common reason for hospitalization in elderly which is also complication of AFib
Stroke
majority of cardioembolic thrombi from in patients with AFib
LAA
persistant atrial fibrillation
sustained AF beyond 7 days; also includes cases of long-standing AF
factors that reduce myocardial blood flow
CVD, MI, thromboembolism, fibrillation…etc
htn, plaque
blood tests recommended for patients presenting with possible AFib
yes; Blood tests can be abbreviated, but should include complete blood count and smear,
thyroid, renal and hepatic function measures, as well as serum electrolytes and the
hemogram (a record of the cellular components of the blood)
what is TEE and when used
look for clot in LAA, patients for whom cardioversion is delayed should be treated to control the ventricular rate and minimize the risk for thromboembolism prior to cardioversion. When
possible, these patients should undergo TEE prior to DCC to exclude intracardiac
thrombus; transesophageal echocardiography - A specialized probe containing an ultrasound transducer at its tip is passed into the patient’s esophagus
holter monitoring
use when: If diagnosis of the type of arrhythmia is in question
As a means of evaluating rate control;
ambulatory electrocardiography device) is a portable device for continuously monitoring various electrical activity of the cardiovascular system for at least 24 hours (often for two weeks at a time)
does lack of symptoms assure that AFib is absent in patients who have demonstrated the arrhythmia previously
No - AFib can be asymptomatic, many patients don’t present until stroke or event, AV nodal blocking drug mask symptoms,
can tachycardia induce AF through an accessory pathway
YES: Tachycardia can also induce AF, through AV node re-entry of electrical impulses,
through an accessory pathway
does transthoracic echo diagnose valvular heart disease? LV size and function? Peak RV pressure?
YES, YES, YES: Valvular heart disease Left atrium (LA) and right atrium (RA) size LV size and function Peak right ventricular (RV) pressure (pulmonary hypertension) LV hypertrophy LA thrombus (low sensitivity) Pericardial disease
disadvantages of direct-current cardioversion
requires sedation, recurrence probability high immediately following
heart failure and AFib
heart failure can lead to AFib and AFib can lead to HF…HF increases risk for AF/AF increases risk for HF…
rate control, rhythm control, strict rate control
rate and rhythm interchangeable
Rate control: A treatment for atrial fibrillation using drugs that maintain an optimal heart rate while allowing the arrhythmia to continue; Rhythm control: A treatment for atrial fibrillation using antiarrhythmia drugs that
maintain the heart’s normal rhythm as set by the sinus node, the heart’s natural
“pacemaker.”; strict rate control: heart rate control of 80bpm,
Vaughn Williams Classification
classified drugs based on MOA
not need to know this:
Antiarrhythmic drug classifications:
I: Sodium Channel Blockers -
1a moderately slow: disopyramide, procainmide, quinidine (not used much today)
1b minimally slowed: lidocaine, mexiletine
1c markedly slowed: flecainide, propafenone (used most commonly today)
II: Beta Blockers
III: Potassium Channels Blockers
amiodarone, bretylium, dofetilinde, ibutilide, sotalol
IV: nondihydropyridine CCBs - verapamil, diltiazem
guideline icons
A thru C: multiple populations evaluated to very limited populations evaluated
Class I to Class III: Benefit decreases and Harm increases
data registry
large-scale, national clinical
registries provide an important opportunity to evaluate current clinical practice, improve quality of practice
pharmacologic cardioversion, what is the time frame that is identified as most successful from the onset of atrial fib
48 hours
when is amiodarone used
rhythm and rate control drug, last resort when other drugs have failed,
RAAS system function
A system in the body that responds
to low blood pressure and decreased blood volume by releasing hormones to help
regulate long-term blood pressure and extracellular fluid volume
does the RAAS cause structural changes in the tissue of people with AFib
YES: Many of the structural changes in atrial tissue associated with AF depend on increased
activity of the RAAS
Upstream therapies
ACE-I, ARBs, ARAs, PUFAs
where are deep veins located in the leg
Centered in leg near the leg bones and enclosed by muscle
inherited and acquired risks for VTE
inherited: antithrombin III deficiency, Factor V Leiden, Protein C deficiency, Protein S deficiency, Prothrombin gene mutation
Dont need to know:
Acquired: age, antiphospholipid antibodies, cancer, central venous catheter, chronic care facility resident, critical illness, HIT, HRT, hyperhomocysteinemia, HTN, immobilization, long-haul flights, CHF, COPD, obesity, oral contraceptives, pregnancy
D-Dimer testing
excludes DVT as diagnosis, D-dimer concentrations rise in the
blood of patients with venous thromboembolism due to fibrinolysis of newly formed
clots; results from degradation of fibrin clots
acute VTE, what agent is favored for parenteral anticoag for the first 5 - 7 days
LMWH
indications to screen someone for a hypercoacuable disorder
family history of absnormal blood clotting, abnormal blood clotting at a young age (<50 years), thrombosis in unusual location (veins in arms, liver, intestine, kidney), idiopathic blood clots, recurrent blood clots, history of frequent miscarriages, stroke at a young age
post thrombotic syndrome
long term complication of DVT
platelets
tiny discs that circulate in the blood stream and are a important component to clot formation
hemostasis
a process which causes bleeding to stop, meaning to keep blood within a damaged blood vessel by clotting
thromoblytics
dissolve clots after they form - not used for AF
RE-MEDY trial
Warfarin vs dabig for extended treatment of VTE
noninferior VTE, superior for bleeds
ADVANCE trials
apixaban and enox (lovanox) has been studied in TKR and THR
patients for thromboprophylaxis, phase 3, I, II, III
ASPIRE trial
The net clinical benefit seen with aspirin led the investigators to call lowdose aspirin an “attractive option” for secondary prevention in VTE patients, not significant in bleeding
hypertension (HTN)
High blood pressure defined as a systolic pressure above 140 mm Hg or
a diastolic pressure above 90 mm Hg. Essential (or primary) hypertension indicates no
known medical condition to explain the condition; secondary hypertension means the
high blood pressure is resulting from another condition such as kidney disease.
Persistent hypertension is a risk factor for heart failure, heart attacks, strokes, and
more. Lifestyle changes, including diet and physical activity, are often encouraged; a
variety of medications can be prescribed to treat hypertension.
CHADS2
Congestive HF 1 pt, HTN 1pt, Age > 75 yrs 1pt, Diabetes 1pt, Stroke prior 2 pts = total 6
what tools do physicians use to estimate patients risk of stroke
CHADS2, CHADSVASC,
consistent factors seen in clinical trials that stand out as consistent risk predictors for stroke; which is most powerful predictor
increasing age over 65 years, history of HTN, history of stroke or TIA, diabetes; systemic embolism is the most powerful predictor
normal INR
2.0 - 3.0
risk factors for AF
age, HTN, DM , obesity, valvular, ischemic, nonischemic structural heart disease
modifiable: HTN, BMI, DM, smoking, prior cardiac disease
recommended for patients with CHADS score of 0
Anticoag,
An individual with a CHADS2 score of
0 – similar to a low-risk patient from the ACCF/AHA/HRS guideline stratification – is not
a candidate for warfarin therapy because of the bleeding risk,
renal disease
kidney disease
medical condition in which the kidneys fail to adequately filter waste products from the blood.[1] The two main forms are acute kidney injury, which is often reversible with adequate treatment, and chronic kidney disease, which is often not reversible.
antiplatelet agents
ASA, clopidogrel, abciximab (ReoPro)
amiodarone, clopidogrel, digoxin, warfarin
warfarin = antiocoag, 3 weeks pre cardioversion, 4 post cardioversion
dig = rate control, digoxin can
be used to control heart rate in patients with AF and HF who do not have an accessory
pathwayand digoxin is effective following oral
administration to control heart rate at rest in patients with AF and is indicated for
patients with HF, LV dysfunction, or for sedentary individuals
amiod = rate/rhythm control, appropriate
choice for a patient with persistent AF, HF, and reactive airway disease who cannot
tolerate either a CCB or a beta-blocker and who has a rapid ventricular rate despite
using digoxin
clopid = antiplatelet, treating AF as dual therapy with aspirin
ACCF/AHA recommend for pts who cannot take warfarin
dual antiplatelet therapy, clopid + ASA
oral anticoag reduces stroke risk
65%, 2/3
Class I recommended strategies for stroke prevention in the current ACC/AHA AF guideline
ASA
Vitamin K Antagonists
anticoagulants that act by interfering with vitamin K-dependent production of clotting
proteins II, VII, IX, and X in the liver such as warfarin
new agents appear to be effective with fewer of the concerns over warfarin differ in MOA
Factor Xa inhibitor, lower in cascade
Don’t need to know:
Dabig: is a direct thrombin inhibitor (DTI)
that works directly with Factor IIa, which is thrombin
binds to thrombin itself to block it from binding to anything else.
Riv/Apix: Direct Factor Xa inhibitors bind
directly to the active site of Factor Xa, blocking its interaction with its substrates. The
direct inhibitors also inactivate Factor Xa bound to platelets in certain situation
ideal anticoag
oral administration,
predictable pharmacokinetics and pharmacodynamics, a low propensity for food and
drug interactions, administration of fixed doses with a low-dose threshold for efficacy but
a high-dose threshold for bleeding complications, a wide therapeutic window, and no
requirement for regular monitoring
ROCKET-AF
riv to warfarin noninferior efficacy
superior bleeds
ACTIVE - W
clop + ASA vs. warf, trial, warfarin proved superior to the combination therapy of clopidogrel and aspirin in
preventing the primary outcome (first occurrence of stroke, noncentral nervous system
systemic embolism, MI, or vascular death) while exhibiting a similar bleeding risk.
proton pump inhibitors (PPIs) for patients on warfarin
reduces GI bleeds
patients with AF, are drug eluting stents more likely than bare metal stents to reduce the need for triple therapy or not
Yes
don’t need to know
should use bare metal to reduce need for triple therapy or reduce time of therapy: using bare metal stents to reduce duration on antiplatelet therapy or avoid long-term warfarin use through use of device therapy, including LAA occlusion devices -
what scenario is triple antithrombotic therapy used for patients with AF
likely scenario will be an AF patient who undergoes stenting
is there a consensus definition of elderly
no - varies, and has changed due to baby boomer growth in older generation
stroke appears to be most prevalent in what population
white
more prevalent with age (9% over 80 yrs)
40% HF have AF
what effect does pregnancy have on AF and stroke
increases risk
Normal QT interval
measure of the time between the start of the Q wave and the end of the T wave in the heart’s electrical cycle. The QT interval represents electrical depolarization and repolarization of the ventricles. A lengthened QT interval is a marker for the potential of ventricular tachyarrhythmias like torsades de pointes and a risk factor for sudden death.
What are the reasons that aging patients face more drug to drug interactions and adverse effects than younger patients?
age related changes in physiology, multiple comorbidities, polypharmacy, low body weight/volume
Is rate or rhythm control used to treat AF and HF
Both
Warfarin and foods that don’t mix
Green leafy veggies - kale, broccoli, spinach
Cranberry juice
Patients being prescribed warfarin usually in safe INR, over safe INR or under safe INR?
Under safe INR as this is when there is risk for clotting
When over there is risk for bleeding
How often monitor INR
Every 2 - 3 days upon initiation until INR within range two consecutive INR checks Then every week until 2 consecutive INR checks Then every 2 weeks ... Then every 4 weeks when dose is stable Geriatric guidelines: Daily until stable 2-3 times per week for 1 to 2 weeks Weekly for 1 month Monthly At home monitoring check weekly
What are pts most concerned with with therapy for AF
bleeding, ICH
Has home INR monitoring improved parameters of AF management
YES
Greatest concern for pts on long term warfarin therapy
Stroke
how many pts assigned to ATRIA bleed risk stratification scheme
Anemia 3pts, severe renal disease 3pts, age >75 2pts, any prior hemorrhage diagnosis 1pt, history HTN 1pt
What effect does Vit K have on warfarin?
Lessen warfarin effectiveness, can reverse effects of warfarin in high concentration
What are the extrinsic factors that should be considered when balancing risks and benefits of AF management?
type of AF; severity of symptoms; associated medical conditions, especially underlying heart disease; age; treatment goals; and therapeutic options.
Why did the FDA change warfarins label in 2010?
To include information on how to dose for identified genotype response,
What is the Watchman device?
permanent
occluder device just behind or at the opening of the
LAA to block formation and release of clots
Meta of warfarin + ASA to clop + ASA show?
W + ASA sign lower risk of TE stroke and all stroke but increase of major bleeds
Diastolic heart failure
HF with preservation of EF because LV is still working well
Cut and sew procedure
Heart surgery for AF, surgeon Cox, Maze” refers to the series of incisions arranged in a maze-like pattern in the atria. Today, various methods of minimally invasive maze procedures, collectively named minimaze procedures, are used
Avoid these drugs in patients with HF
AAD because they have not proarrhrythimic effect
Conditions the increase risk for AF
HTN, high cholesterol, heart disease, smoking, sedentary lifestyle, excess weight, various meds, sleep apnea, alcohol abuse, caffiene
Non-controllable: family history, advancing age, congenital heart disorders NOT DIABETES
NYHA HF criteria
A widely used classification of
severity or extent of heart failure. Class I indicates no symptoms and no limitations;
class II, mild symptoms and slight limitations to activities, comfortable at rest; class III,
more marked limitations due to symptoms, comfortable at rest; and class IV, severe
limitations, experiences symptoms even at rest.
Procedures on LAA to prevent stroke
several transcatheter approaches have
been developed to isolate or occlude this “cul-de-sac”
in the heart. endotheliazation of plug,
One device, the WATCHMAN implant,
has looks a little like a jelly-fish, atriclip, amplatzer cardiac plug, lariat
Indications for AF ablation
patients for whom one antiarrhythmic drug has failed, subsequent drug treatment is
likely to fail, too; thus, AF guidelines suggest that such patients may benefit from
catheter ablation
Catheter ablation also is a first-line treatment approach for patients with recurrent typical
or isthmus-dependent atrial flutter, demonstrating more successful short- and long-term
outcomes compared to antiarrhythmic agents.
Why elderly with AF difficult to manage
many changes to heart and vasculature with increasing age, increase risk for anticoag bleeds, higher risk OAC assoc hemorrhage, under represented population in clinical trials, optimal therapy a challenge with polypharmacy a necessity, comorbidities
Warfarin used in elderly and younger patients
Elderly: under dosed, under utilized
younger: misused
After used to prevent post op AF
BB
Post op AF - rate or rhythm control?
Most often BB and CCBs, thus rate control
Is cardio version used as a treatment for pts who develop AF after heart surgery?
While most patients will not require cardioversion of postoperative AF, the
evidence it increases long-term risk suggests these patients should be
candidates for intensive risk reduction.
What is the one chronic illness that is growing worldwide that increases the risk of developing AF; other disorders that increase risk of AF?
Worldwide, mitral valve disease is the most common cardiac cause of AF. Other: HTN, CAD, HF, prior MI, genetics, sleep apnea, obesity, tachycardia
What agent reduces risk of new onset AF in pts that undergo CABG upon discharge
Warfarin
What are predictors for development of post op AF; which is most consistent?
Advanced aged - most consistent
gender male, dig, PAD, chronic lung disease, valvular heart disease, left atrial enlargement, previous cardiac surgery, discont BB, prep atrial tach, pericarditis, elevated postoperative adreneric tone
Does AF have a potential proarrhythmic effect.
YES - ventricular pacing
Does a defibrillator function to restore normal sinus rhythm?
Yes, reset
How does a defibrillator function to restore normal sinus rhythm?
This device is placed in the body with
leads to the heart to detect cardiac rhythm and deliver electrical shock and pacing as
needed; the pulse generator may be external to the body. When the device senses
tachycardias (very rapid heartbeats) it sends pacing shocks that restore normal heart
rhythm. If this is unsuccessful, it can use overdrive pacing or cardioversion to stop rapid
heartbeat. If the heart is in fibrillation (irregular heartbeats, quivering), the ICD sends a
stronger defibrillating shock to normalize the heartbeat. If the pacing is too slow, an ICD
acts like a pacemaker to increase heart rate.
When should a pacemaker be used in AF?
tachy and brady
What is used to treat bradyarrythymias?
Atropine IV
Artificial pacemaker
What is done in AV node modification?
not a complete heart block, injure or slow electrical beat
Ablate and pace
AV node ablation and pacemaker insertion
ACC\AHA guideline: do they recommend AV node modification as first line treatment for AF?
No - not without attempting a prior trial of medication to control vent rate in pts with AF
Michel haissaguerre famous for
pulm vein trigger AF
ACC/AHA guideline recommend for pts whom one AAD has failed and subsequent drug treatment is likely to fail
Catheter ablation
According to guidelines, in AF pts without mechanical heart valves who require surgery how long can anticoag be interrupted without bridging therapy?
Up to 1 week
Interrupting anticoag therapy for surgery can lead to stroke that can result in major disability or death in 70% of pts
TRUE
In warfarin therapy, percentage of pts where risk of bleeding is low risk
<1%
Drug most often used in bridging therapy to provide anticoag when warfarin stopped
Heparin
What are the indications for AV node ablation?
Isolate pulmonary veins, create barrier in right atria to prevent macro entrant rhythms from being sustained
Indication: intolerance to meds such as amiod and warf, contraindications to meds, cerebrovascular accident despite anticoag, intolerance to arrhythmia, failed catheter ablation, patient choice
What is ablation to cafés and what should it do?
A site where there is unusual electrical pattern, maybe due to long or short electrical wave
CFAEs appear to represent macro reentry sites for AF
Ablating of these lines should in theory stop AF
What is the strongest predictor of AF as a complication of acute MI?
Increasing age
Up to 22% in pts over 65yrs
Also more common in pts with HF, renal disease, DM, pulm disease)
Risks increased in pts with AF
Stroke, TIA, HF, death/all cause
Pts at high risk of VTE recurrence due to idiopathic thrombosis or irreversible risk factors should have anticoag for how long?
At minimum 6 months to indefinitely
Distal
Farthest end from the trunk or head
Inferior
Below or toward the feet
Proximal
Closest part nearest the trunk or head
Superior
Above or near the head
Predictors of VTE recurrence
Age, BMI. Neurological disease, active cancer, lupus anticoagulant, antithrombin, protein c deficiency, protein s deficiency, persistent increased plasma fibrin D-dimmer
Are Elderly pts with structural heart disease ideal pts for catheter ablation?
No not ideal
Ideal pt - symptomatic AF, young (50), impaired QOL, minimal or no structural heart disease, poor response to or intolerance of pharm therapies
are most patients who undergo ablation of the AV node pacemaker dependent after the procedure
Permanent pacemaker implanted
Patients dependent on pacemaker
Lifelong anticoags and possibly AAD
Are patients taking warfarin at enough of an increased risk of falling compared to their age-matched peers to justify not taking warfarin?
No
Pt on anticoag who needs stent implanted would be best served with what type of stent?
Bare metal
AF increases risk for…
Stroke, HF, MI, death all cause (VT)
Non pharma therapies for AF
LAA occlusion, surg ablation, pacing, atrial defibrillator, per cutaneous ablation, AV node modification/ablation
Types of upstream therapy
ACE-I, ARB, ARAs, statins, omega-3 FA
Causes of AF
Holiday heart synd (alcohol), stimulants, surgery, stress due to pneumonia or other illness, PE, electrocution, MI, percarditis, myocarditis, hyperthyroidism
cut and sew most often used for what
valvular surgery
question 70
TRUE
