Cardiac Rhythm Analysis 2 Flashcards
What are the features of ventricular rhythms?
1) WIDE QRS
Depolarization spreads abnormally along muscle cells and not proper conduction pathways
2) QRS, ST, T look BIZARRE
Conduction is abnormal, repolarization is also abnormal
What do abnormal ST and T waves indicate in ventricular rhythms?
Abnormal conduction, NOT ischemia or infarct
Premature Ventricular Complex: Criteria, types
Early beat, wide and bizarre QRS > 0.12 secs
Unifocal PVC
Multifocal PVC
R-on-T
(The R wave of the PVC falls on the preceding T wave)
Multiple PVCs in a row: 3 or more is a “run of V-Tach”. Paired PVC are “couplets”
Ventricular bigeminy/trigeminy (every 2nd/3rd beat is a PVC)
What is it called when you have more than 3 PVC in a row?
Run of v-tach
Premature Ventricular Complex: Etiology, physiology
Ectopic site in the ventricles, reduces stroke volume by 30-60% due to early depolarization, impaired ventricular contraction and loss of atrial kick
Hypokalemia, dilated ventricles (CHF), myocardial ischemia or infarct
Premature Ventricular Complex: Treatment
Do not require treatment if isolated, treat underlying cause.
If pt symptomatic with increasing PVCs, amio may be given esp if underlying rhythm has a lengthened QT interval
Idioventricular escape rhythm: Criteria, physiology, etiology
QRS wide and bizarre, HR 20-40
Both SA and AV node failed, ventricles initiate impulses to try and sustain life. No atrial activity, very low CO. EMERGENCY
Expected- dying pt
Unexpected- hyperkalemia, severe acid base imbalance
Idioventricular escape rhythm: Treatment
If withdrawing care, no treatment. Otherwise investigate why other pacemakers failed, epinephrine for CO, atropine tried to increase SA node activity, pacing
DO NOT ADMINISTER VENTRICULAR ANTIARRYTHMICS
Can we give amio for Idioventricular escape rhythm?
NO do not administer ventricular antiarrythmics
Accelerated idoventricular escape rhythm: Criteriam, etiology, physiology
QRS wide and bizarre, HR 40-100
Common reperfusion arrythmia, transient, seen after inferior MI with SA/AV node involvement
An ectopic site in ventricles fire at 40-60bpm. Irritable focus usually secondary to ischemia or infarct
Accelerated idoventricular escape rhythm: Treatment
Give O2 if required to reperfuse cardiac tissue. In-between rhythm is hard to treat, usually self-limiting. If sustained HR is LOW and the pt becomes SYMPTOMATIC, then atropine may be trialed to increase SA function
Meds that speed up rhythm may cause more dangerous ventricular arrythmias, ventricular antiarrythmics may further slow down rhythm
Ventricular Tachycardia: Criteria, etiology
QRS wide and bizarre, monomorphic (uniform QRS), polymorphic (QRS shape varies)
Myocardial infarct or ischemia, electrolyte imbalance, acid base imbalance, anything that causes long QT
Ventricular Tachycardia: Physiology
Ectopic sites in the ventricles fire at fast rate, taking over pacemaker functioning. Treatment focuses on suppressing irritable ectopic site.
Torsades de Pointes: Etiology
Meds that lengthen QT interval (Haldol), electrolyte imbalances (hypo-mg, hypo-K)
Ventricular tachycardia: Treatment
Assess pt if stable, unstable, or pulseless
1) Stable (BP normal, pulse strong)
12 lead ECG and consider adenosine if monomorphic and regular for diagnostic purposes
Give antiarrhythmics (amiodarone)!!!
2) Unstable (BP dropping, pulse weak, symptomatic)
Synchronized cardioversion
3) Pulseless (No BP, no pulse)
Defibrillate immediately 120-200J
Continuous CPR with drugs administered during CPR
MD may defibrillate again as needed during session
Epi every 3-5 mins
Amio may be given
Ventricular fibrillation: Criteria, etiology, physiology
Chaotic irregular deflections, no pattern
Myocardial infarction, electrolyte imbalance, acid base imbalance, anything that causes long QT
Ectopic site in the ventricles fire but is not organized or uniform