CONDUCTION SYSTEM DISORDERS Flashcards
NOT INCLUDING DEFINITION OF EACH DISORDER
Common symptoms for conduction system disorders
palpitations (extra beat, flutter, heart beating out of chest)
dyspnea, CP, diaphoresis (sweating), dizzy, syncope, cough, fatigue, weakness
Dx for conduction disorders (tests)
12 lead EKG
holter monitor (24hr-30day)
implantable loop recorder (ILR)–useful for cryptogenic CVA
cryptogenic CVA- embolic stroke event and underlying cause remains unknown
implanted loop record (ILR)
- how long
- what does it record
- for what specific conditions
3 yr monitor, triggered symptoms events recorded
- spotaneous recording of tachy, brady, pauses, irreguar rhythms
- mri compatible
- cryptogenic stroke, syncope, suspected afib
L sternal border around 4th rib space, outside rib cage around muscle
SVT types
MC is AVNRT
atrial tachycardia
multifocal atrial tachycardia
junctional tachycardia
Paroxysmal SVT/AVNRT causes
excessive caffeine, alc, ischemic heart disease/post MI, structural heart disease, myocarditis/pericarditis, PE, chronic lung ds, meds (amphetamines), idiopathic
think: this girl loves to drink caf and alc, and smoke so much (lung ds) she got an Mi and CAD
Junctional tachycardia
no (clear) p wave
tachycardic
SVT/AVNRT tx
- hemodynamically stable (narrow vs. wide complex) vs unstable
- definitive tx
stable
- vagal manuever (bear dowwn, cough, hold breath)
- narrow complex: adenosine (6mg IV then 12 mg IV push)
- wide complex: amiodarone
unstable
- synchronized cardioversion
definitive tx
- radiofrequncy ablation (cauterize)
sarahs very tachy, takes addy to make her narrow
sarahs very wide, keeps saying am i(odarone) fat?
SVT prevention
beta blocker: atenolol, metoprolol, carvedilol
calcium channel blockers: diltiazem, verapamil
SVT meds- ADENOSINE
- med type, side effects, and contraindication
med type- vasodilator (<10 second half life)
side effects: can cause transient heart block at AV node
CP, dyspnea, facial flush, lightheaded, METALLIC TASTE AND IMPENDING DOOM
CI- asthma, long QT syndrome, 2nd/3rd degree heart blocks
SVT meds- AMIODARONE
- med type, side effects/adverse, and contraindication
med- class III antiarrhythmic (58 hrs half life)
side effects- nausea, fatigue, tremors
adverse effects- hepatotoxicity, pulm fibrosis, optic neuritis, thyroid dysfunction, skin discoloration (blue skin/sun exposure+ drug for years)
CI- 2nd/3rd degree block, prolonged QT, pregnancy, sinus node dysfunction
A-fib
- diff lengths of the condition
- diff ventricular rates
paroxysmal- less than 7 days
persistent- longer than 7 days
chronic- arrhythmias present at least 1 year W OUT resolution
ventricular rate
- rapid (>100), mod (60-100), or slow (<60)
remember ventricular rate can vary
A-fib: causes
MC CAUSE- excessive alc or withdrawal
other:
- ischemic or structural heart disease (mitral stenosis)
- cardiomyopathy (dilated/hypertrophic)
- PE
- hyperthyroidism
- sepsis
- anemia
- pheochromocytoma
holiday heart syndrome
A-fib tx (phases)
<48 hrs- cardioverison
>48 hrs- anticoag + rate control 3 weeks (slow HR), then cardioversion
- rate control= beta blockers, calcium channel, digoxin
- rhythm control= antiarrhythmic meds
- TEE (imaging)
- ablation therapy
anticoag, rate control, cardioversion- for pt at high risk of thromboembolic events
3 weeks- bc it takes 3 weeks for body to naturally break down clot
A-fib, TEE
transesophageal echocardiogram
- to visualize left atrial appendage
CHADS2 vs. CHADSVASC score
CHADS2- use CHADSVASC score determine stroke risk in pt with afib
- stroke risk # means how many strokes pt is at risk for getting each year
CHADSVASC- determine whether to use no tx, aspirin, or full anticoagulation based on certain factors
CHA2DS2VASc Score
who do we anticoagulate for a fib
CHF= 1 pt
HTN= 1 pt
Age
- 65-74 = 1 pt
- >75 = 2 pt
Diabetes = 1 pt
Stroke/CVA/TIA= 2 pts
Vascular ds= 1 pt
Sex is female= 1 pt
0 pts= none or ASA (aspirin)
1pt= ASA or full anticoag
2pt or >= full anticoag
age is 2 options, stroke risk is 2 options
REMEMBER IF BEING FEMALE IS ONLY POINT THEN IT DOES NOT COUNT
CVA/TIA (neurovasc events like amaurosis fugax)
vasc ds (MI, PAD, aortic atherosclerosis)
A-fib anticoagulation meds- WARFARIN/COUMADIN
- action, labs to monitor
Action- blocks vit K production in liver (factors 2, 7, 9, 10, protein C and S)
- metab by cytochrome P450
monitor- INR
- standard goal 2-3, mechanical valves 2.5-3.5
A-fib: how do you reverse warfarin
vitamin K or fresh frozen plasma
A-fib: WARFARIN
- what are factors that affect INR while on warfarin?
DEC INR
- leafy green veggies, pheyntoin, phenobarbital, st johns wort (used for depression)
INC INR
- alc, abx (quinolones, amoxicillin, metronidazole), steroids, amiodarone
A-fib: DIRECT ORAL ANTICOAGS (DOAC)
- use, types, labs to monitor, reversal agents, warning
use- pt with non-valvular afib (htn, thyroid ds)
types- dabigatran/pradaxa (direct thrombin inhibitor), rivaroxaban/xarelto (10a inhib), apixaban/eliquis (10a)
labs- NO MONITORING INR
reversal agents- pradaxa use praxbind, xarelto/eliquis use andexxa
warning; in renal impairment pts as all meds metabolize through the kidneys
what is valvular afib
mitral stenosis, mechanical heart valves
afib- watchman procedure
plug into the L auricle
- prevents stroke, good option for pt unable to take anticoags
- pt on aspirin/plavix for a month following procedure
A flutter- causes
EXACERBATED IN RESP PATIENTS
- COPD
- structural heart ds (atrial septal defect- scar tissue, conduction loops around)
- cardiomyopathy (reentratnt tissue, but presents as flutter)
- myocarditis
- hyperthyroidism
- idiopathic
a flutter is around tricuspid valve
A flutter Tx
- anticoag
-** same tx as afib** - ablation therapy most successful
V tach- causes
- CAD (coronary artery ds)–> MC IN PT after MI
- cardiomyopathy
- congenital defects
- prolonged QT syndrome (causes polymorphic)
- ilicit drug use
- meds
V tach Tx
- pulseless
- unstable
- stable (NSVT vs sustained)
- medications
pulseless- defibrillation
unstable- syncrhonized cardioversion
stable
- non sustained- beta blocker therapy
- sustained-(ACLS PROTOCOL) synchronized cardioversion, anti arrhythmics (IV amiodarone, lidocaine, procainamide)
meds- sotalol, amiodarone, mexiletine (all antiarrhythmics)
V tach- underlying causes and Tx for each
Myocardial ischemia- cardiac cath
cardiomyopathy- echocardiogram to see ejection fraction, management
electrolyte abnormalities- K, Mg, Ca
Polymorphic Vtach/torsades de pointes Tx
- first line: magnesium 1g IV push
- defibrillation
v-fib: causes
MC CAUSE- ischemic heart disease (CAD)
- antiarrhythmics (cause prolongation of QT interval)
- afib with RAPID ventricular response
- drug toxicity
- sepsis
- hemorrhagic shock
- electrolyte abnormalities
V-fib tx (definitive and ACLS) and prevention
definitive tx- defibrillation
ACLS protocol- defib–>epinephrine–>defib–> epinephrine
24-48 hrs following conversion- amiodarone IV
tx underlying cause- need ischemic evaluation
prevention- AICD placement (Automatic Implantable Cardioverter-Defibrillator)
Cardiac arrest- definition and MC cause & rhythm
sudden cessation of blood flow due to failure of the heart
- inability of contraction, death within mins
-
**MC CAUSE IS CAD/ischemic heart ds
MC RHYTHM IS VFIB **
Cardiac arrest- causes
- MC CAUSE IS CAD
- ATHEROSCLEROTIC DISEASE also contribute to blockage
- HF
- genetics (prologned QT, brugada syndrome, hypertrophic cardiomyopathy)
- low magnesium, potassium
- anemia, hemorrhage
- trauma
when septum hypertrophies and HR is tachy, prevents blood going out to systemic circ, and not as much blood into coronary arteries
THIS CAN HAPPEN IN YOUNG ADULTS TOO
Brugada syndrome
- definiton
- increases risk for what
- onset
TEST-DONT HAVE TO IDENTIFY RHYTHM ON EKG
- genetic inheritance, mutation of sodium ion channels in cardiac muscle (>60 mutations)
- ST elevations, neg t wave in V1-V3 without strtuctural cardiac abnormalities
- inc risk sudden death for vfib
- onset adulthood
Brugada syndrome Tx
definitive tx: ICD placement
(implantable cardioverter defibrillator)
Sick Sinus Syndrome- definition and MC in what population?
chronic dysfunction of SA node
- includes sinus brady, tachy, pauses, and arrest
MC in elderly
Sick sinus syndrome- symptoms and causes
SS? MOST COMMONLY ASYMPTOMATIC
causes
- myocardial scarring
- meds (b blockers/CCB, antiarrhythmics, digitalis, lithium, methyldopa)
- genetic (familial SSS)
- sarcoidosis, amloydosis (infiltrative issues can cause scarring in conduction system)
Sick sinus syndrome Tx
discotinuation of medications
**definitive Tx: permanent pacemaker placement **
RBBB and LBBB
- leads
- causes
RBBB
- V1&2
- idiopathic, inc R ventricular pressures (cor pulmonale, PE, myocardial ischemia)
LBBB
- V5&6
- myocardial fibrosing, HTN, Myocardial ischemia (LAD), cardiomyopathies
Bundle Branch Blocks R vs L (conduction)
RBBB
- left conduction not in sync with right conduction
LBBB
- right conduction not in sync with left conduction
RBBB and LBBB tx
BOTH- rule out underlying causes/diseases
AV block causes
- aging
- CAD (MI)
- rheumatic heart ds
- lyme ds
- sarcoidosis
- hematomachrosis
- hyperthyroidism
- congenital
- hyperkalemia
AV block Tx
- 1st, 2nd (type I and II), and 3rd av block
1st degree- NO Tx
2nd degree
- type I- no tx unless symptomatic
- type II- permanent pacemaker (mroe likely to progress to 3rd)
3rd degree- permanent pacement (PPM)
