Conduction disorders Flashcards
What are some symptoms of atrial fibrillation?
Fatigue and exertional dyspnea, palpitations, dizziness, angina, syncope, irregularly irregular pulse, reduced exercise capacity, HOTN, insidious onset of HF, weakness – from low CO
What can atrial fibrillation and flutter cause that should be concerning and treated for?
clot that can cause a risk for stroke
What’s the most common chronic arrhythmia?
afib
What can cause a fib?
cardiac, lung diseases, valvular disease, hyperthyroidism, systemic illness, stress, alcohol, hyperadrenergic state, extreme activity
What are indications for hospitalization of afib?
Active ischemia
Heart failure
Hypotension
Difficult rate control
Evidence of organ hypoperfusion
(confusion, renal injury)
What are indications for rhythm control in a fib?
Hemodynamic instability
Failure of rate control
First episode
Young patient
CHF
Reversible cause
What does this ECG indicate:
irregularly irregular rhythm w/ narrow QRS, no p wave, atrial rate 300-600 BPM, ventricular 75-175 BPM
a fib
If the a fib’s if HR>100, what do you call it?
a fib w/ RVR
What is paroxysmal a fib?
terminates spontaneously or w/ intervention in <7 days (reoccur/not reoccur)
What is persistent a fib?
continuous >7 days
What is permanent Afib?
joint decision between clinician + patient to not puruse treatment
What is nonvalvular afib?
absence of rheumatic MS, replaced heart valve, or valve repair
If there is new onset a fib in a patient, what should you order?
thyroid study
What score dictates the need for anticoagulation therapy in a fib?
CHA2DS2VASC criteria - >2 in men or >3 in women
CHA2DS2-VASc criteria
CHF
HTN
Age>75 (2)
DM
Stroke, TIA, thrombus (2)
Vascular disease
Age 65-74
Sex (female)
total of 9
What are the three steps to consider maintenance of afib?
1) rate control (1st line for minimal w/ no symptoms) w/ BBs or CCBs
2) reversion + return to sinus rhythm w/ cardioversion if new onset or if remains symptomatic
3) a fib –> anticoagulation therapy
What is the ultimate backup rate control drug?
amiodarone
What rate control drug do you use in HF?
digoxin
Can you use BBs in lung disease?
no
Warfarin is for anyone with ____
mechanical valves, mitral disease, assistant devices
Why are DOACs preferred?
no monitoring necessary
How do you treat a fib>48 hours with unkown cause?
3 weeks of anticoagulation before cardioversion OR rule out thrombus with TEE and then 4 weeks of anticoagulation after cardioversion
Who needs aspirin treatment in a fib?
everyone who has CHD or peripheral vascular disease
How do you treat an unstable a fib patient?
IV heparin + IV rate control (beta blocker, CCB) + cardioversion (120-200 joules)
What can atrial flutter look like in symptoms?
Palpitations, dizziness,, tachycardia, fatigue, weakness, dyspnea, presyncope, hypotension, angina, reduced exercise capacity
Can have AMS
Are men or women more predisposed to atrial flutter?
men with CAD or HTN heart disease
What can cause atrial flutter?
similar to a fib
How do you treat a flutter?
rate control w/ BBs or non di-CCBS
cardioversion 50-100 joules
atrial flutter ablation can be used to prevent coagulation therapy
Can you use pharmacological cardioversion in atrial flutter?
no not recommended
In who is MAT most seen?
COPD patients
What’s the HR of MAT?
> 100 BPM
How do you treat MAT?
oxygen, treatment of underlying condition, and rate control –
preserved LV function: BBs, non-di CCBs, digoxin, adenosine, IV flecainide, IV propafenone
non-LV: digoxin, diltiazem amiodarone
How do you treat sinus tach?
underlying disease
BB for inappropriate sinus tach
How do you treat sinus brady?
atropine if symptomatic, repeated every 3-5 min up to 3 mg
In who is sinus brady normal?
athletes
In who is sick sinus syndrome the most common?
fibrous tissue in older people
How can sick sinus syndrome present?
sinus brady –> pause –> atrial tachy –> a fib
Can you get sick sinus syndrome on an EKG?
maybe but unlikely, need Holter
How do you treat sick sinus syndrome?
identify and correct factors (could be anything), symptom control, permanent pacemaker placement
symptomatic = permanent pacemaker w/ dual chamber pacing + atropine
With bradycardia + alternating ventricular tachycardia = permanent pacemaker with automatic implantable cardioverter-defibrillator (AICD)
Sinus arrhythmia increases during ______ and decreases during _______
inspiration,, expiration
What can cause a 1st degree heart block?
increase in vagal tone or meds like digoxin, BBs, verapamil, dilitiazem
How do you treat a second degree Type I block?
asymptomatic = observation
symptomatic = atropine, epi w/ or w/o pacemaker
How do you treat a second degree Type II block?
Symptomatic = atropine, pacing
Permanent pacemaker
How do you treat a third degree block?
Temporary pacing, permanent pacemaker, atropine for bradycardia
which block rarely progresses?
1
How do you treat PACs?
none if asymptomatic
if symptomatic, beta blockers, and stopping precipitating factors
What’s the difference between RBBBs and LBBBs?
left is more from disease like CAD, HTN, aortic valve, cardiomyopathy
RBBB common in people without structural defects
3 or more consecutive PVCs
non sustained v tach
How do you treat PVCs
asymptomatic = no tx
treat underlying cause, remove precipitating factors
symptomatic or with high PVC burden in patient w/ CHF = beta blockers
High PVCs in CHF = catheter ablation
What are torsades de points caused from?
v tach, acquired or congenital, >100 BPM
Are torsades or v fib taller waves?
torsades
How do you treat torsades?
cardioversion, IV magnesium sulfate, discontinue drugs
What’s the MCC of v fib?
ischemic heart disease
What’s the normal BPM of v fib?
300
How do you treat v fib?
Immediate DC defibrillation + CPR
Up to 3 sequential shocks to establish rhythm
If persists –
Continue CPR
Intubation if necessary
IV epi
Refractory -
Add IV amiodarone
Lidocaine, magnesium, procainamide
If you are successful w/ v fib, what else do you start the patient on?
Continuous IV infusion of amiodarone
Implantable defibrillators (at risk)
Long term amiodarone
What is sustained v tach?
> 30s + HOTN + symptomatic that leads to v fib
What is non sustained v tach?
brief, self-limiting, asymptomatic (+CAD or LV dysfunction = risk for death)
Does v tach respond to vagal manuevers or adenosine?
no – SVT will, so differentiate if you can’t interpret the EKG
How do you treat sustained v tach?
Implant cardioverter defibrillator for all!
Mild + stable = IV amiodarone
Unstable = immediate synchronous DC cardioversion → IV amiodarone
How do you treat nonsustained v tach?
Asymptomatic: treat underlying cause
Symptomatic: beta blockers (metoprolol, carvedilol), CCB (verapamil, diltiazem), antiarrhythmic drugs (amiodarone), radiofrequency ablation
Chronic = beta blocker therapy
What are the two causes of SVT?
reentry with AV node + using accessory pathway
causing either orthodromic (narrow) or antidromic (wide) pathways
In who are SVTs common?
younger, female, ischemic heart disease, digoxin toxicity, flutter w/ RVR, excessive caffeine/alcohol
SVT Is usually _____ and _____
paroxysmal and self-limiting
How do you treat SVT?
narrow = vagal maneuvers, adenosine
BBs or CCBs
unstable = direct cardioversion
How do you treat WPW syndrome?
radiofrequency ablation
can do medically IV procainamide or ibutilide
What must you avoid with WPW syndrome?
digoxin, BBs, CCBs, adenosine
