Dysrhythmias Flashcards
Sinus Pause/Arrest
May occur from increased vagal tone, myocarditis, MI and digitalis toxicity
Typically lasts 2 seconds - 2 minutes
Atropine may be given if hemodynamically unstable
What med should be given to a patient with symptomatic Sinus bradycardia?
Atropine 1mg IV
Temporary Pacemaker
Where does SVT originate?
Above the His bundle.
What might cause SVT?
digitalis, asthma meds, caffeine, ephedra, cocaine, meth Stimulants
What does SVT generally start with?
A PAC or PVC
S/S of SVT
Palpitations Dizziness SOB Anxiety CP/tightness
SVT Tx
Vagal maneuvers Carotid Massage Adenosine 6mg IV fast push. or of unsuccessful... Cardioversion, IV Beta blocker/CCB
SVT prevention
Beta Blockers
CCB’s
Digoxin
SVT ablation (permanent)
Wolff-Parkinson-White Syndrome (WPW)
Congenital defect - any age. Men > Women
Form of SVT where an accessory pathway bypasses the AV node.
AKA AV reciprocating arrhythmia
Bypassing AV node can cause re-entry tachycardia
WPW S/S
Palpitations Tachycardia DIzziness Dyspnea Anxiety Syncope
WPW EKG symptoms
PR interval < .12ms Delta wave (slurred QRS uptake)
WPW Long-term Tx
Depends on frequency and symptoms
Radiofrequency ablation
Beta blockers, CCB’s, Flecainide
WPW Acute Tx
Vagal maneuvers
IV adenosine (6-12 mg fast push)
OR
IV diltiazem or verapimil
Paroxysmal Atrial Tachycardia (PAT)
Atrial rate 150 - 250
P wave morphology varies
Usually requires no tx
Usually terminated with vagal maneuvers
Premature Atrial Contractions (PAC’s)
Discharge from non-sinus atrial pacemaker
P’ wave marks PAC
May be precursor to Afib
PAC Tx
Asymptomatic (avoid triggers (stimulants))
Symptomatic: Beta blockers
Wandering Atrial Pacemaker
Seen in normal hearts and diseased hearts
Variable rate
More than 3 different P wave morphologies
Usually no tx required
May lead to multifocal atrial tachycardia
Multifocal Atrial Tachycardia
Wandering atrial pacemaker with a rate over 100 bpm
Usually doesnt cause hemodynamic instability
Causes of multifocal atrial tachycardia
Lung dz, COPD AMI Sepsis Hypokalemia Low magnesium Ma be a precursor to Afib
Multifocal atrial tachycardia tx
Tx underlying medical problem
Suppress rate with BB, or CCB
Atrial Fibrillation
Most common arrhythmia Micro re-entry circuit Atrial rate is 350 - 450 No distinguishable P waves Irregularly irregular
Causes of Afib
Underlying cardiac dz Valvular dz, Heart failure, IHD Pericarditis Thyrotoxicosis PE Pneumonia Alcohol OD Post-op thoracic surgery Sleep Apnea HTN
Afib may result in?
Decreased Cardiac Output
INR goals for Afib?
2.0 - 3.0
Rate goals for Afib?
between 60 and 110
Diltiazem
Beta Blockers
Digoxin
When is it safe to cardiovert without anticoagulation in Afib?
Less than 48 - 72 hours of Afib
Atrial Flutter
Macro re-entry circuit Atrial rate 250 - 350 Ventricular rate 150 2:1 3:1 4:1 pattern regularly irregular Classic sawtooth on EKG
A flutter is indicative of?
Diseased hearts (CHF)
Precursor to Afib
Tx depends on level of hemodynamic compromise
Aflutter Tx
Cardioversion
Class 1A antiarrhythmics
BB, CCB, Digoxin
Junctional Tachycardia
Junctional rhythm with a rate of 150 - 250
More common in women
Usually initiated by PAC
Junctional Tach tx
Vagal maneuvers
Adenosine* DOC
Long-term: BB, CCB
1st degree AV block
PR interval > .20
Occurs in healthy and sick hearts
Usually don’t need tx
2nd Degree AV Block Type 1
Wenchebach
Occurs in the AV node, above His bundle
often transient
Often asymptomatic - no tx
Wenchebach EKG
Variable rate
PR grows wider and wider until the QRS is blocked completely, then it resets.
2nd Degree AB block Type 2
Mobitz
Usually occurs below His bundle
May progress into higher degree AV block
Type 2 block EKG findings
Variable rate
normal P wave
Widened QRS associated w/ BBB
PR may be normal until dropped QRS
Type 2 block Tx
More serious than Type 1
Artificial pacing
Usually requires permanent pacemaker
3rd Degree Block
AV dissociation
Sinus impulses are completely blocked upstream of the ventricles
3rd Degree block causes
digitalis toxicity
Acute infxn
MI
Degeneration of tissue
3rd Degree block EKG findings
Normal atrial rate
Ventricular rate usually less than 70
QRS may be normal or widened
3rd degree block tx
External pacing and atropine for acute episodes.
Permanent pacing for chronic complete block
Premature Ventricular Contractions (PVC)
Increasing circulating catecholamines Coronary ischemia Hypokalemia Low magnesium Drug toxicities
PVC EKG findings
Variable rate
P wave usually obscured by QRS
Wide QRS
May occur in singles, couplets, or triplets
Bigeminal PVC’s
one normal beat and one PVC repeated
Trigeminal PVC’s
two normal beats and one PVC
Ventricular Tachycardia causes
Triggered by ischemia, electrolyte abnormalities
Hypokalemia is also an important trigger
MI
Cardiomyopathy
Pulse Vtach Tx
Cardioversion
Amiodarone
Pulseless Vtach
Defibrillation
Amiodarone
Torsades de Pointes
Twisting about the points
Upward and downward deflection of QRS
Torsades de Pointes causes
Long QT drugs
electrolyte imbalances
Myocardial ischemia
Torsades de Pointes Tx
Synchronized cardioversion
IV magnesium, potassium
Overdrive pacing
Ventricular Fibrillation
AKA sudden cardiac death
ABsence of cardiac output
Occurs with AMI
Vfib Tx
ACLS protocol
Immediate defib
Treat underlying cause
Implantation of ICD
Idioventricular Rhythm
Widened WRS
dying heart rhythm
Pacemaker most likely needed
Caused by myocardial ischemia, infarction
Asystole
In the presence of AMI is almost always fatal
Complete cessation of any electrical or mechanical activity
Asystole Tx
CPR, O2 IV, Intubate Transcutaneous pacing Epi 1mg IV push q3-5m Atropine
Pulseless Electrical Activity (PEA)
Electromechanical dissociation
There is electrical activity, but no mechanical response
EKG shows sinus, but NO pulse
PEA 6 H’s
Hypoxia Hypovolemia Hypoglycemia Hydrogen Ions (Acidosis) Hypothermia Hypo/Hyperkalemia
PEA 6 T’s
Toxins Tamponade Trauma Tension pneumothorax Thrombosis (cardiac) Thrombosis (pulmonary)
PEA Tx
Correct underlying cause
Epi, Atropine
CPR
Which pathway do electrical impulses take in WPW?
Through the kent bundles
You will see delta waves and short PR
