Atrial Arrhythmias Flashcards
sinus Pause/arrest
variable time when there is no sinus pacemaker working
-transient absence of sinus P waves on EKG
what can a sinus pause/arrest lead to?
an escape rhythm or asystole
what can cause a sinus pause/arrest?
ischemia, inflammatory, infiltrative or fibrotic dz of the SA node, excessive vagal tone, sleep apnea, digitatlis
what are sx of sinus pause/arrest?
dizzy, presyncope/syncope, rarely death
how is sinus pause/arrest tx?
most of the time, nada.
discontinue or decrease meds
why would sleep apnea cause sinus pause/arrest?
holding breath, so the pressure change can cause a dropped beat
ectopic rhythm
deals w/ impulse formation
-impulse orginates from tissue other than SA node
what are some causes of an ectopic rhythm?
another pacemaker cell fires at a rate faster than the SA node=premature beat
or
escaped beat
what is an escaped beat>
slowing of the SA node rate allowing faster focie to take control
what are three tipes of ectopic beats?
Premature Atrial Contractions (PAC)
Premature Junctional Contration (PJC_
premature ventricular contractions(PVC)
what is a PAC?
Other pacemaker cell in the atria fires at a rate faster than the SA node
Triggers a premature heartbeat
Acceleration of HR usually abolishes most PACs
-Can be predictive of future development of Atrial Flutter/Fibrillation
sx of PAC
often ASx
will see a “resetting” of the SA beat
palpitations, dizziness
how does exercise affect PACs
may make them go away (increase HR)
tx of PAC
nada
BB
what is an ectopic atrial tachycardia
when an ectopic atrial focus fires more quikkly than the underlying sinus rate
episodes aren’t usually sustained for a extended period
(random fast rhythm)
what is a wandering atrial pacemaker?
created by multiple atrial pacemakers firing at its own pace
varying distances cuases 3 + different morphologies of P waves (the varing P wave axis causes diff int hthe morphology
EKG evaluation of WAP
Rate: 100 Rhythm: Irregularly irregular P wave: At least 3 different morphologies P:QRS ratio: 1:1 PR interval: Variable, depending on foci QRS: Normal
what is multifocal atrial tachycardia
tachycardic WAP
> 100 bpm
what dz state is associated with MAT?
COPD (pulmonary dz)
sx of MAT
palpitations, dizzy, SOB
how to you tx MAP?
tx underlying condition
Mg and K stability
CCB, BB, ablation
what is paroxysmal supraventricular tachycardia?
AKA AV nodal re-entrant tachy
**episodic
- dual pathways (slow and fast) w/in AV node until terminated
- think of the heart pc
what dz state is PSVT found?
structural heart dz
what are the sx of PSVT
palpiations, angina, SOB, abrupt
what is tx of PSVT
mechanical-vagal stimulation
what are drug tx of PSVT?
adenosine or CCB
how does adenosine work in PSVT
blocks electrical conduction through the AV node
what dz state must one be careful with when giving adenaosine
reactive airway dz bc adenosine can cause bronchospasms
what do CCB do for PSV?
rapidly induce AV block and break episodes of reentrave
what is last resort for PSVT?
ablation
what level do you cardiovert a pt with PSVT?
synchronized electrical cardioversion (100J)
Atrial flutter
originates in the right atrium
250-350 bpm
what does the ventricular rate depend on in A flutter
AV node conduction (most common is 2:1 so 150), but can have 3: 1, or 4:1
what is the most dangerous A:V rater?
1:1 bc it can lead to ventricular fib
what are sx of a flutter
-fatigue SOB palpitaions dizzy presyncope, syncope
tx of a flutter: rate control
CCB, BB, amiodarone
digoxin if heart failure
tx of a flutter: chemical conversion
synchornized cardioversion: 50 J
IV ibutilide
drug of choice for chronic a fluter
dofetilides, but can also use dronedarone, amiodarone, sotalol, procainamide,
A Fib
chaotic firing of numerous pacemaker cells
-no atrial contraction, no PWave
what is the mose common cardiac arrhythmia
a fib
what population is most likely to get a fib
men and with increasedin age
> 80
what are causes of a fib
valvular disoders, heart dz, dilated cardiomayopathy, HTN, sleep apnea, thyrotoxicosis, pericaditis, Cardiothoracic surgery, pulmonary dz, holiday heart, fatigue, DM
what is paroxysmal AFib>
AF that terminates spontaneously or with intervention within seven days of onset. Episodes may recur with variable frequency
what is persistent AFib?
fails to self-terminate within seven days. Episodes often require pharmacologic or electrical cardioversion to restore sinus rhythm. While a patient who has had persistent AF can have later episodes of paroxysmal AF, AF is generally considered a progressive disease
lons standing Afib
> 12 mnths
Permanent AF
Persistent AF where a joint decision by the patient and clinician has been made to no longer pursue a rhythm control strategy.
Nonvalvular AF:
AF in the absence of rheumatic mitral stenosis, a mechanical or biprosthetic heart valve, or mitral valve repair
sx of AFib
same as any rate issues
tx of Afib new onset and unstable
present ins Rapid ventricular rate
+/- cardioversion
when would a pt need to be cardioverted in Afib
active ischemia
organ hypoperfusion (cold clammy skin, confusion, acute kidney injury)
severe manifestations of heart failure (pulmonary edema
what about stable pts in afib?
+/- thrombus
+/-HF
pt w. thrombus or high risk (including being in a fib for more than 48 hours)
tx with anticoags (heparin or enoxaprin and warfarin or dabigatran) for 3-4 wks prior to concersio
what are rate conrol methods in the presence of HF in pts w/ afib
dioxin, amiodarone, dronedarone
if no HF, and in a fib,
metoprolol, esmolol, or CCb
what can be used to chemically convert pts in afib?
flecainaide, propafenons, amiodarone, dronedarone, ibutilide
what is Wolff-Parkinsons-White syndrome?
due to an abnormal accessory electrical conduction pathway btw the atria and vetricles
signals travel down the bundle of kent and stimulate the ventricles to contract prematurely “pre-excitation syndrome”
what is WPW assocated with?
tachycardias bc this abnormal pathway doesn’t share the rate slowing properties of the AV node
what are sx of WPW
palpitations, dizzyiness, syncope, anxiety, fatigue, CP, SOB
- often occurs during exercise
- stimulate and alcohol can trigger
*think of kid playing soccer and gets CP
what are tx for WPW
vagal maneuvers
Class 1a or 1c antiarrhythmics if not candiate for ablations
what you must avoid tx in pts w/ WPW
BB, CCB, and digoxin bc won’t help for this pathhway
what will you see on an EKG in a pt with WPW
delta wave- no Q wave, slurs up into the R wave
what is a junctional rhythm?
occurs when the normal pacemaking fx of the atria and SA node is absent or another pacemaker takes over
EKG findings in a junctinal rhythm?
Rate: 40-60 Rhythm: Regular P wave: None or inverted P before/QRS complex P:QRS ratio: None or 1:1 PR Interval: None or short QRS: Normal to narrow
what is an accelerated junctional rhythm
originates in a junctional pacemaker that fires faster than the normal pacemaker
what would you see o an EKG in accelerated junctional rhythm?
Rate: 60-100, if >100 junctional tachycardia
Rhythm: Regular
P wave: None or inverted P before/QRS complex
P:QRS ratio: None or 1:1
PR Interval: None or short
QRS: Normal to narrow
