W3 D3 - Ventricular Rhythms Flashcards
Can you analyze ST and T waves during ventricular rhythm?
No, they are bizarre
Represent abnormal conduction
What is the criteria for diagnosis for a PVC?
causes and treatments
Early beat, wide, bizarre QRS > 0.10 sec
an ectopic site in the ventricle becomes pacemaker
Causes
* low electrolytes; potassium, calcium, magnesium
* acidosis, CHF, symmathomimetics, hypoxia, hypertension, cardiomyopathy
Treatment
* treat underlying cause, hypokalemia
* amiodarone for increasing PVCs
Explain the variations in rhythms with PVCs
R on T - R wave of PVC starts on or before T wave
Run of VT - 3 or more PVCs
Couplets - 2 PVCs
Unifocal - shape of PVC is similar to another, same foci firing
Multifocal - PVCs have different shapes, multiple foci firing
Ventricular bigeminy (rhythm) - every other QRS is a PVC, must be sustained
Ventricular trigeminy - every third QRS is a PVC
an ectopic site in the ventricle becomes pacemaker
What is the criteria for diagnosis for idoventricular escape rhythm?
causes and treatment
QRS wide and bizzare
HR 20-40
an ectopic site in the ventricle becomes pacemaker
Causes
* dying patient, hyperkalemia, MI, severe acidosis, 3rd degree AV block, BB or CCB overdose
Treatment
* treat bradycardia; atropine, epinephrine, dopamine, pacing
* figure out why pacemaker sites failed
* DO NOT administer ventricular antiarrhythmics
What is the criteria for diagnosis for accelerated idoventricular escape rhythm?
causes and treatment
QRS wide and bizzare, HR 40-100, no P / T waves
an ectopic site in the ventricle becomes pacemaker
Causes
* transient reperfusion following acute MI
Treatment
* resolves itself
* hard to treat as speeding up and slowing down will cause problems
What is the criteria for diagnosis for Ventricular tachycardia?
causes
QRS wide and bizzare, HR > 100
an ectopic site in the ventricle becomes pacemaker
Monomorphic
* regular rhythm
* same shape/uniform QRS
* from same ectopic site
Polymorphic
* irregular rhythm
* different QRS shapes
* from different ectopic sites
Torsades de Pointes
* twisting around isoelectric line; changing polarity from new impulses from different ectopic locations
* pointy at the top, then shortens & twists, pointy at the bottom
* causes: lengthened QT so any meds or hypomagnesemia, hypokalemia
Causes
* acute MI, ischemic heart disease, electrolyte imbalance, long QT, overdose, trauma
* cariomypathy, myocarditis, MI scarring, CHF
* meds that lengthen QT; antiemtics, antipsychotics
How do you treat V-tach or V-fib?
Stable - asymptomatic
* BP = normal, strong pulse
* adenosine if monomorphic / regular just to diagnose, if doesnt work then confirms ventricular
* antiarrhythmic: amiodarone, procainaide, sotalol
Unstable - symptomatic
* BP = dropping, pulse weak
* Synchronized cardioversion
Pulseless - No BP, no pulse
* 120-200J biphasic defibrillator
* CPR
* shock
* CPR epinephrine
* shock
* CPR
* amiodarone / lidocaine
What is the criteria for diagnosis for ventricular fibrillation?
cause and treatment
Irregular chaotic deflections, no pattern
* multiple ectopic sites fire off in the ventricle
* depolarization does not spread throughout ventricle
* quivering
Polymorphic v-tach vs. v-fib
* amplitude is smaller for v-fib than v-tach
Causes
* myocardial ischemia, cardiomyopathy, myocarditis, electrolyte imbalance, tamponade
* blunt chest trauma, hypothermia, long QT, overdose
* respiratory arrest, tension pneumo, PE
* sepsis, seizure, lightning strike
Treatment
* same as V-tach but harder to fix
What’s the difference between sychronized cardioversion & defibrillation?
EC
* SA node is firing so must be careful
* still a QRST, must be timed outside of T wave
Defibrillation
* no synchronization needed
* used to get SA node firing again
What is the criteria of diagnosis for Pulseless Electrical Activity?
Electrical activity with no physical pulse
* the electrical system is working but there is a contractility issue
Causes
* 5Hs hypovolemia, hypoxia, hydrogen ions (acidosis), hypo/hyperkalemia, hypothermia, hypoglycemia
* 5 Ts tension pneumo, tamponade, toxins, thrombosis pulmonary, thrombus coronary
Treatments
* treat hypovolemia, fluid bolus
* CPR, epi
* treat any other causes
