arrhythmias & afib Flashcards
6 things in the SVT category
- sinus tachy
- atrial flutter
- atrial tachy
- AV nodal reentry
- WPW
- afib
usually has a reason like fever, pain, anemia, hypoxemia, anxiety, hyperthyroid, pheo; you treat the patient not the pulse rate
sinus tachycardia
when the underlying cause of tachycardia is ruled out, you could use BB, ablation but this is hard to treat and its their default
inappropriate sinus tachycardia
whats the difference between typical and atypical aflutter? in their rates?
- with typical you know where the macro-reentrant circuit is
- atypical has faster atrial rate
how are both types of A. flutter diagnosed w/ maneuvers?
adenosine or valsalva will NOT terminate the tachycardia; it exposes the sawtooth pattern
macro-reentrant arrhythmia around a functional or anatomical circuit
typical a flutter
what is the most common type of flutter
typical a flutter
anatomical vs functional circuit
- anatomical–path around a barrier like valve, scar
- functional– from heart conditions like long QT syndrome
atrial rate of 240-340bpm
typical a flutter
what direction does most typical a flutter go?
counterclockwise
* negative sawtooth in II,III,avF
* positive in V1
atrial rate of 340-430 bpm
atypical atrial flutter
includes several tachycardia that originate in atria with a different P wave morphology
atrial tachycardia
atrial rate of 140-240 bpm
atrial tachycardia
what causes atrial tachycardia (3)
- automatic
- triggered (caffeine, sleep, calcium, etc)
- reentrant
why isnt anticoags always required with atrial tachycardias
theres enough propulsion of blood bc its not going THAT fast
if unsure, can give it
3 tx for atrial tachycardias
- rate control w/ BB, CCB +/- digoxin
- antiarrhythmics if rate control fails
- electrophysiology study w/ RF ablation
dual AV node physiology with both a slow and fast pathway between the atria & ventricle; can be unproblematic
AVNRT
when does AVNRT become problematic?
when the two pathways are going in opposite direction and the slow gets there first instead
narrow QRS + no P or QRSP
make sure to look at ECG pics
AVNRT ECG
atrial tachycardia that can terminate w/ valsalva or adenosine bc they cause an AV block
AVNRT
accessory pathway or bypass tract (not the AV node) btwn A & V located around tricuspid or mitral annulus; can have mulitple pathways in one patient
WPW syndrome
does having an accessory pathway imply SVT occurrence?
NO
short PT interval + delta wave
WPW
early activation of ventricles through the accessory or bypass tract
delta wave
tends to have narrow QRS and involved reentrant circuit w/ retrograde conduction through accessory pathway
WPW arrhythmia
result of adenosine and valsalva in WPW
turs it into sinus node
how can WPW patient develop wide QRS tachy?
if theres anterograde conduction through accessory pathway
wide QRS complex tachycardia originating from ventricles; AV dissociation on ECG
V tach
tachycardia where origin can be in right or left ventricle
normal heart VT
type of tachycardia where sx include palpitations and dizziness frequently related to exercise; sudden death is RARE
VT in normal heart symptoms
tachycardia involving reentrant mechanism around a scar in venetricle
VT in structural heart dz (most are in ischemic heart dz)
tachy where sx include syncope, very symptomatic/hypotensive or with sudden death
VT in structural heart dz
how is v tach diagnosed?
ECHO
who should you refer patients to cardiologist or electrophysiologist
- all with SVT, VT or significant bradycardia
- if new sx develop after successful ablation
2 tx for acute atrial flutter
- rate control + anticoagulant for stroke prevention
- cardioversion
its been less than 48 h since a flutter and you want to do cardioversion, what must be done?
put patient on IV heparin
its been over 48h since a flutter and you want to do cardioversion. what needs to happen? (2)
- anticoagulation x 3 consecutive weeks before
- if no appropriate anticoagulation then do TEE to exclude atrial clot
regardless of timeline, if you do cardioversion what must be done after?
give anticoag for at least a month after
chronic a flutter management w/o sx
rate control + anticoagulation
2 chronic mangement for a flutter w/ sx
- anti-arrhythmics
- electrophysiology study w/ RF ablation
3 tx of AVNRT
- rate control
- antiarrhythmics if having it everyday
- EP study + RF ablation if refractory/intolerance to meds
best tx for WPW/bypass tracts?
EP study w/ RF ablation
we should avoid ____ when treating WPW because it can lead to preferential conduction through the accessory pathway
AV nodal blocking agents like BB, CCB, digoxin
2 tx of V tach in normal heart
- rate control
- final therapy: EP study w/ RF ablation
2 tx of v tach in structural heart dz
- ICDs w/ option of anti-arrhythmics
* palliative therapy w/ EP study and RF ablation
the most common sustained cardiac arrhythmia
a fib
irregularly irregular SVT with fine oscillations of the baseline d/t absence of organized atrial activity
afib ECG
atrial rate of 400-600bpm
afib
mostly asymptomatic but sx could include palpitations, dizziness, fatigue, general weakness, poor exercise tolerance, mild dyspnea and presyncope
afib sx
sx reflect decreased CO as result of rapid ventricualr rate
sx d/t hypoperfusion and include sig hypotension (double digits), altered mental status, refractory chest pain and decompensated CHF
unstable afib
adverse sequelae of afib & a flutter
increased risk of atrial thrombus formation that can lead to cerebral &/or systemic embolization (acute ischemic stroke)
natural hx of afib
paroxysmal > persistent > permanent
tx of acute afib (stable vs unstable)
- stable: rate control to slow AV node conduction
- unstable: direct current synchronized cardioversion
4 tx options of chronic afib
- rate control (preferred), antirhythmics
- cardioversion
- RF cather ablation or surgical MAZE
- anticoag– NOAC, warfarin, dual antiplatelet therapy
when do you give anticoag with chronic afib
CHADS score of 2+ bc then risk of stroke is higher than risk of bleeding from the anticoagulant
4 indications for catheter based radiofrequency ablation
- symptomatic drug-refractory afib
- drug intolerance
- tachy-induced cardiomyopathy
- special populations– WPW
4 indications for catheter based radiofrequency ablation
- symptomatic drug-refractory afib
- drug intolerance
- tachy-induced cardiomyopathy
- special populations– WPW
when is direct current cardioversion most successful when treating Afib
when used w/in 7 days after Afib onset
why would you do TEE before cardioversion
to ensure no atrial clots
indications of cardioversion in afib
for unstable AFib or long term Afib
2 C/I to cardioversion
incessant arrhythmia
thrombus (delay it)
