Atrial Arrhythmias Flashcards
What are the abnormal rhythms that are caused from the atrium (p-wave) ?
- premature atrial contractions
- supraventricular tachycardia
- atrial flutter
- atrial fib
What is the intrinsic (underlying) rhythm ?
the rhythm that the pt is in most of the time
- excluding the abnormal beats
- NSR may not be the underlying rhythm
What is a atrial kick ?
where 70% of blood flow into the atrium is passive (before atrial ctx) and the other 30% happens when the atrium actually contracts
- decrease atrial ctx = decreased CO
What is a premature atrial contraction ?
When the p-wave comes early
- causes irregular beats but has a NSR
What are some causes PAC and the treatment ?
Causes:
- emotional stress
- electrolyte imbalance
- caffeine
- tobacco
- underlying heart disease
Tx:
- not clinically significant but can lead to arrhythmias
- goal is to withdraw source of stress
- beta blockers may be need
What is the cause of the supraventricular tachycardia (SVT) ?
due to loss of atrial kick and it decreases the filling time from speed of contraction
- regular rhythm but loses the P-wave
- sudden onset (not gradual)
- consistent tachycardia
What is the HR of SVT in adults, kids, and infants ?
- adults: >160
- kids: >180
- infants: >220
What are the causes of SVT and the treatments ?
Causes:
- electrolyte imbalance
- heart disease
- stress
- caffeine
- stimulant use
- tobacco
- deep inspiration
- viral disease
- Wolf Parkinson’s white defect
Tx:
- vagal stimulation
- adenosine
- synchronized cardioversion
What is vagal stimulation ?
stimulation of the vagus nerve to decrease HR
- bear down and blow through a straw/syringe
- if cannot follow directions: carotid massage (one side at a time)
- babies: surprise cold response
What is the purpose of adenosine ?
acts as a restart (like unplugging and plugging back in)
- drug of choice for SVT
- expect a period of systole after admin
- short half-life, give fast
- give as close to central as possible and big gauge needle
What is the last resort option for SVT ?
synchronized cardioversion
What causes a atrial flutter ?
when there is a short circuit in the pathway that allows the electrical signal to move too fast around the heart
What is the rhythm of a atrial flutter ?
causes multiple “flutter/wave” motions between each QRS wave
- the flutters are defined so the atria is still contracting
- regular pattern but can become irregular
What can cause a atrial flutter and the treatment ?
Causes:
- heart disease (CAD, HR, cardiomyopathies, congenital heart defects)
- pulmonary embolus
Tx:
- often resolves itself
- same tx as A.fib
What happens in atrial fibrillation ?
a short circuit in the pathway of electrical signals of the atrial is now going too fast AND is now very disorganized
- SA node dysfunction
- leads to no actual atrial squeezing
- results in loss of atrial kick
What is the rhythm in A.Fib ?
- irregularly irregular
- no defined p-wave (because no real atrial contraction is happening)
- irregular pulse
What are some causes of A.fib ?
- post op CABG surgery
- heart disease (HF, CAD)
- hypertensive heart disease
- ACS pt’s
- alcohol
- caffeine
What happens in A.Fib with rapid ventricular response (RVR) ?
happens when HR >100
- too many atria firing signals leads to increased ventricular response
- leads to worsening decrease of CO
What are the S&S of A.Fib with RVR ?
more likely to be symptomatic (think signs of decreased CO)
- dyspnea
- palpations
- hypotension
- dizziness
Goal is to decrease HR which will decrease symptoms
What is the first main goal of treatment for A.Fib with RVR ?
slow the ventricular rate so we take meds that will decrease HR and controls symptoms
- calcium channel blockers (diltiazem)
- beta blockers: metoprolol
What is the second goal of treatment for A.Fib with RVR ?
convert to NSR by chemical or electrical conversion
- if new onset (<48 hrs): given anti-dysthymics like Amiodarone and if this doesn’t work then do synchronized electrical conversion
- unknown onset (>48 hrs): need to give anti-coagulants like apixiban or warfarin for 3-4 weeks and then try to get a NSR with synchronized electrical conversion
What is a synchronized cardioversion ?
listens for the heart and syncs up with the heartbeat to give a jolt of electricity during a specific point in the cardiac cycle
- light sedation
- usually elective procedure so need consent
- A.Fib, Flutter and SVT (organized rhythms)
What 2 surgical procedures can be done for dysrhythmias ?
- Ablation
- MAZE procedure
What is an ablation ?
done in cath lab and they locate the source of the arrhythmias and ablate in (burn or freeze it)
What is a MAZE procedure ?
surgical procedure that creates scar tissue in a “maze” pattern that prevents disorganized electrical impulses
What types of meds does someone who has chronic A.Fib take ?
- always on a anticoagulant
- likley on beta or calcium channel blocker
- could be on amiodarone (PO)
- may be on digoxin if they have HF
Why do you need to know the onset of A.Fib when treating it ?
over time if the atrium is not contracting normally then blood clots can form
- can cause a stroke from Lt side of heart or a PE from the Rt side
- doing cardioversion on a unknown onset could dislodge any potential clots
When is it necessary to give anti-coagulants for A.Fib ?
for unknown onset or if the A.fib has lasted for more than 48 hrs
