Dysrhythmias Flashcards
Sinus Pause/Sinus Arrest Treatment
Possible pacemaker insertion
Atropine 1mg IV may be given if hemodynamic instability is noted
Sinus Bradycardia Treatment
Symptomatic and hemodynamically unstable:
Atropine 1mg IV
Temporary Pacer
No tx. if symptomatic!
Sinus Tachycardia Treatment
Treat underlying cause
Calcium channel blockers: Diltiazem, verapamil
Beta Blockers in Symptomatic tachycardia
SVT causes
digitalis, asthma medications, or cold remedies
Caffeine, ephedra
Cocaine, meth
EKG in PSVT
Heart rate 140-240 Regular rhythm P wave different from the normal sinus rhythm P wave often buried in QRS (can't see) QRS is narrow and of normal morphology
Supraventricular Tachycardia (SVT) treatment
Vagal Maneuvers:
Carotid massage, start at R side
Adenosine (Adenocard) 6mg IV
Supraventricular Tachycardia (SVT) treatment If adenosine is unsuccessful:
Consider cardioversion if patient is hemodynamically unstable (requires sedation)
Or IV Beta or calcium channel blocker
Wolff-Parkinson-White Syndrome (WPW)
Form of SVT
Accessory pathway that bypasses the AV node (Bundle of Kent)
heart rate is typically greater than 200
PR interval is short <.12ms
The upstroke of the QRS wave is slurred (delta wave)
delta wave
The upstroke of the QRS wave is slurred, seen in WPW
Paroxysmal Atrial Tachycardia(PAT)
Atrial rate150-250/min: may conduct to ventricles but the AV node will try to block impulses.
P wave - morphology usually varies from sinus
Originates from an irritable atrial focus
Premature Atrial Contractions (PACs)
Discharge from non-sinus atrial pacemakers
P-wave preceding may not look like the P waves that originate from the sinus node
Very frequent PACs may be a precursor to the development of atrial fibrillation
Most common encountered arrhythmia in clinical practice
Atrial Fibrillation
Class 1A antiarrythmics To restore sinus rhythm if necessary
Pronestyl (Procainimide)
Quinidine (Cardioquin)
Class III antiarrhythmics
Sotalol (Betapace)120-160mg po BID
Ibutilide (Corvert) IV only
**Amiodarone – titrated up to 400mg po qday
**Long-term toxicity issues, lungs, thyroid, liver and eyes need monitoring.
Class IC antiarrhythmics
Propafenone (Rythmol) 300-600mg po qday
Flecainide (Tambocor) 50-100mg po BID
Cardioversion for Atrial Fibrillation
Less than 48-72hours of a-fib:
Safe to cardiovert (May need to R/O LA thrombus…TEE to see if atrial thrombus present prior to cardioversion)
If duration unknown:
Rate control
Anticoagulate x 4-6 weeks then cardiovert
Anticoagulants x 6 weeks after successful cardioversion or indefinitely if patient was unaware that they were in atrial fibrillation
Junctional Escape, Accelerated Junctional Rhythm EKG findings
Narrow complex QRS
Retrograde P wave
Junctional Tachycardia Rhythms Treatment
Acute Treatment:
Vagal maneuvers
Adenosine
Long term treatment:
Beta Blockers
Calcium Channel Blockers
Class 1A, 1C and III antiarrythmics for resistant cases
1st degree AV Block EKG
PR interval greater than 0.20
2nd degree AV Block-Mobitz Type I(Wenckebach)
occurs in the AV node above the Bundle of His
often transient and may be due to acute inferior MI or digitalis toxicity
Treatment is usually not indicated as this rhythm usually produces no symptoms
PR interval gets progressively longer until a QRS is dropped (or blocked)
2nd degree AV Block-Mobitz Type II
occurs below the Bundle of His and may progress into a higher degree AV block.
Out of the blue drops a Q for type II, PR is normal until dropped QRS
Treatment = permanent pacemaker
3rd degree heart block EKG findings
Atrial rate is normal
Ventricular rate is less than 70/bpm
Atrial rate is always faster than ventricular rate.
P waves: normal with constant P-P intervals, but not “married” to the QRS complexes.
QRS: may be normal or widened
Premature Ventricular Contractions(PVC’s)
Rate: variable
P wave – usually obscured by the QRS with the PVC
QRS: Wide > 0.12, morphology is bizarre
Premature Ventricular Contractions Treatment
Lidocaine - Class 1B antiarrhythmic
Procainamide (Pronestyl) - Class 1A antiarrythmic
Amiodarone (Cordorone) – Class III antiarrhythmic
Replace Magnesium, potassium if appropriate
