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