Cardiac Arrhythmias Flashcards
Cardiac arrhythmias are defined as what?
abnormalities in cardiac rhythm and/or
conduction.
When are Arrhythmias usually caught and diagnosed
Detected because patients present with symptoms or detected during a routine screening
What is the gold standard for monitoring and diagnosing cardiac arrhythmias.
ECG
True/False
Depending on the dysrhythmia and patient presentation, treatment can be just ABCs, IV, Oxygen, Monitor.
True
Symptoms for arrhythmias can range from asymptomatic to what?
palpations, dizziness
Presyncope and syncope
What Rhythm
Beat originates in the SA node and follows the appropriate conduction pathways. The intrinsic rate is 60-100 beats/min and the rhythm is regular. Every beat has a P wave, and every P wave is followed by a QRS complex.
1) PR interval remains constant.
2) R-R interval is regular and constant.
3) P-P interval is constant.
Normal Sinus Rhythm
Heart rate slower than 60 beats/min due to increased vagal tone on normal pacemaker, organic disease of the SA node, or due to medications.
Sinus Bradycardia
Severe Bradycardia may cause weakness, chest pain, lightheadedness, N/V, confusion, or syncope. The rate usually increases with exercise or administration of Atropine. What beats per min is severe brady
< 45 beats/min
Normal or abnormal?
In healthy individuals in excellent physical condition sinus bradycardia to rates of 50 beats/min or lower.
Normal
EKG Finding of what
1) Heart rate < 60 beats/min
2) Normal and consistent P wave morphology followed by QRS complex.
3) Normal PR interval
Sinus Brady
Unstable is defined as what?
(1 Changes in mental status.
(2 Ischemic chest discomfort.
(3 Hypotension
(4 Signs of shock.
(5 Acute heart failure.
Treatment for Sinus brady UNSTABLE pt
1st give Atropine 0.5 mg IV push and repeat q 3-5 minutes for a maximum of 3 mg.
-If Atropine ineffective prepare for transcutaneous pacing OR
-Consider Dopamine IV infusion at 2-10 mcg/kg/min OR
-Epinephrine IV infusion 2-10 mcg/min (use 1:10,000 epinephrine
mixture).
Treatment for Sinus brady Stable pt
obtain vitals, obtain 12 lead if able, attempt to identify and treat underlying causes.
Atropine does not work for any patient that has undergone what surgery? and why?
Heart Transplant
Vagus Nerve is cut and not put back together, the heart is essentially innervated
What medication works by inhibiting all vagal input into the SA node.
l
Atropine
What rhythm
Heart rate faster than 100 beats/min caused by rapid impulse formation from the SA node.
The rate infrequently exceeds 150 beats/min
Tachycardia
EKG Findings for what?
1) HR > 100 beats/min
2) P wave is followed by a QRS complex and each QRS has a P wave preceding it.
3) QRS complex is normal duration (< .12 seconds).
Sinus Tachycardia
Treatment for Sinus Tachycardia
1) ABCs, monitor, IV, Oxygen to maintain saturation > 94%.
2) Assess appropriateness of clinical condition.
3) Usually Sinus Tachycardia has an identifiable etiology. Once identified then treat accordingly (dehydration, fever, stimulants, infection, pain, etc.)
If no identifiable etiology for sinus tachycardia is determined and patient is unstable then what?
start ACLS protocol
Unstable is defined as what?
(1 Changes in mental status
(2 Ischemic chest discomfort
(3 Hypotension
(4 Signs of shock
(5 Acute heart failure
Term:
Paroxysmal
comes and goes
Term:
Supraventricular
originating above the ventricles
True/false
Psvt is the Most common paroxysmal tachycardia and often occurs in patients with structural heart disease
False
often occurs in patients without structural heart disease
EKG Findings for what?
1) HR 150-240 (commonly HR is 160-220)
2) Regular R-R interval
3) Narrow QRS complex
4) P wave often buried in the narrow QRS complex
Paroxysmal Supraventricular Tachycardia (PSVT)
What rhythm?
Paroxysmal Supraventricular Tachycardia (PSVT)
Physical findings for PVST include what?
1) May be asymptomatic
2) Frequently associated with palpitations, mild chest pain or
shortness of breath.
3) Episodes usually begin and end abruptly
4) May cause syncope
5) May cause AMI
Psvt
What Mechanical Measures should be attempted if patient is stable. what does it do?
Vagus stimulation
increase Vagal tone
Vagus stimulation methods
Valsalva
Breath hold
Dunk face in bowl of ICE cold water
Carotid sinus massage
_______ will interrupt up to 50% of PSVT (firm but gentle pressure over the right carotid sinus for 10-20 seconds, if unsuccessful then attempt over the left carotid sinus)
Carotid sinus massage
True/False
For a more effective carotid sinus massage you can apply pressure on both carotid sinuses at the same time
FALSE.
U NO DO BOTH SIDES
Psvt
If vagal maneuvers fail in a hemodynamically stable patient, then use what? How effective are these?
IV AGENTS 90% effective
What are the IV meds you would use for PSVT? what one is first line?
Adenosine - use first line if available
Beta Blockers – second line
-Metoprolol 5 mg IV repeat dose every 5 minutes up to 15 mg max
Calcium Channel Blockers – second line
-Diltiazem: 0.25 mg/kg IV over 2 minutes
What is the dose for adenosine?
6 mg IV push very quickly followed by saline flush quickly. Repeat next dose with 12 mg IV push quickly if 6 mg dose did not
work. May repeat once more 12 mg dose if needed but that is the max you can use.
30mg MAX
MOA of what medication.
Slows AV node conduction time, interrupts AV node reentry pathways. Metabolized by erythrocytes and vascular endothelial cells
Adenosine
In a patient with PSVT who is hemodynamically unstable what intervention would be most successful?
synchronized electrical cardioversion at 50-150 J
What is an accessory electrical pathway or bypass tract between the atrium and the ventricle bypassing the AV node and can predispose to reentrant arrhythmias.
Wolf Parkinson White Syndrome (WPW)
Can Wolf Parkinson White Syndrome (WPW) be Associated with PSVT rhythm
Yes
EKG findings for what?
1) Short PR interval ( < 0.12 seconds).
2) Wide, slurred QRS complex called a delta wave.
Wolf Parkinson White Syndrome (WPW)
What is the arrow pointing to? What could arrhythmia could this be?
-Wide, slurred QRS complex called a delta wave
-WPW
If your pt with WPW arrhythmia is unstable what intervention would you do?
immediate synchronized cardioversion with 50-150 J
If your WPW pt is stable what interventions are used?
-vagal maneuvers just like in PSVT treatment
-Adenosine
-Metoprolol
What is the most common arrhythmia characterized as Multiple areas of atrial myocardium continuously discharging causing the atrium to fibrillate rather than contract in an organized manner
Atrial Fibrillation
Afib
True/False
The heart rate may vary but the R-R pattern is Normal.
False
R-R Rate is irregularly…. irregular
EKG of what?
A Fib
EKG finding for what?
1) R-R interval is irregularly irregular
2) Atrial rate ~ 400 beats/min and presents as fibrillation waves (wavy baseline).
3) Ventricular rate will depend upon how many of the atrial beats get conducted from the AV node which can range from bradycardia to tachycardia (with rates as high as 170-180 beats/min).
A Fib
Up to 2/3 of patients experiencing their 1st episode of A-fib will spontaneously revert to sinus rhythm within how long?
24 hours.
Patients with AF > 48 hours are at risk for what?
cardioembolic events
Patients with AF > 48 hours not be cardioverted until what?
anti-coagulated for a minimum of 3 weeks prior to attempting elective cardioversion.
If the A FIB pt is unstable what is the intervention
synchronized Cardioversion at 100-200 J