Cardiac Rhythms and Rhythm Disturbances (Ventricular Tachy-Blocks)

  1. See handout on amiodarone. 
    #1 drug for getting rid of ventricular beats. 
  2. Ventricular Tachycardia?
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    • IVR with HR 100-150/minute
    • ↓ CO symptoms
    • May be pulseless
    • May defibrillate or Cardiovert
  3. Premature beats
    • Will come from one of the three natural Pacemakers
    • Will have elements of that pacemaker
    • May or may not perfuse
    • May or may not have significant consequences
    • May not interrupt the cardiac “Rhythm”
    • When there is an additional beat, the heart recalibrates to land on exactly where is should be if the extra beat had not happened. = compensatory pause. Is nice because you don't have to worry about the "regular" beat falling on the premature beat's T wave.
  4. Atrial premature beats
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    • or
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    • Typically caused by fluid overload. 
    • Count as HR if they perfuse. 
    • Premature atrial usually will perfuse.
  5. Premature Ventricular contractions (beats)
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    • Will not have atrial kick or preload. 
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    • If 3 or more but returns to normal = unsustained VT. 
    • Rhythm is now too chaotic. 
    • Two in a row can also be called back-to-back. 
  6. What are these?
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    • A stable (compensatory pause) rhythm is better than a chaotic one.
    • Less PVCs is less dangerous than more PVCs. 
    • Uniform is better than multiform. 
    • Any PVC in a strip with a long QT is dangerous. 
  7. What is Torsades de Pointes
    (Twisting of points)
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    • IS NOT VTAC!!! Do not defibrillate! Infuse with Mg++. 
    • IF YOU DO defib, you can break the rhythm but pt will relapse right back into TDP. 
    • Pt in TDP will have visible signs of distress. 
  8. What can cause PVCs?
    • the big disease.
    • Low serum K+-->worse kinds of PVCs. 
  9. What is a garret?
    Weird route of electrical impulse from IVRs. 
  10. Atrial flutter/atrial fibrillation
    • Atrium is no longer sending signals from the SA node
    • Less organized atrium may be due to stretching, volume overload, ischemia, valvular disease, cardiomyopathy
    • No “atrial Kick” (reduces CO up to 30%)
    • Always has potential to be Thrombogenic because platelets within atrium are getting stirred up, crashing into each other, and lysing. Treat with Coumadin.  
    • Flutter vs. fib? Fib is less organized. Flutter will have HR ~300BPM.
    • HR will change randomly rather than in response to activity demands. This is a problem any time the HR needs to respond to sustain life, ie nfxn, blood loss, v BP, ect.
    • HR is no longer simulated by neurogenic stimuli (SNS) but random
    • CO may not equal metabolic needs
    • Rate control to 60-100/minutes will be the goal
    • May cardiovert out of rhythm to NSR if caught early
    • May do “Maze” procedure or EP ablation to control rhythm: path for SA electrical impulse is cauterized into surfacer of the heart to improve rhythm.
  11. What does atrial flutter look like?
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    • May occasionally get a QRS. 
    • Usually will see A-Fib, not flutter.
  12. What does Atrial Fibrillation look like?
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    • If pt has irregular heart rate, assume a-fib unless you can prove otherwise. 
    • Assess for volume status (dehydration/volume overload).
    • A-fib will AWAYS be irregular.
    • Assess for crackles
    • Assess for JVD.
  13. What do you need to know about Heart Blocks.
    • Any physiologic pacemaker can fail
    • Some heart blocks are benign and the serious forms can result in ↓CO and death
    • Some heart blocks may progress from one to the next worst
    • Any heart block is more serious in the face of myocardial tissue ischemia or infarction
  14. What does 1st degree heart block look like?
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    • ECG will have prolonged PR interval. 
    • Escemic tissue between SA and AV node forces impulse to "go around." 
    • No symptoms and no treatment. 
  15. 2nd Degree Heart Block aka
    Type 1
    Mobitz 1
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    • Progressive lengthening of the PR interval, until it can not be conducted and a QRS complex is “dropped”. Cyclic patterned and considered stable. 
  16. 2nd Degree Heart Block Type II, aka
    Classic 2nd Degree
    Mobitz II
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    • All components are normal and a P wave is not followed by a QRS complex. This can be a one beat event or have multiple “dropped “ QRS complexes 
    • P wave no followed by QRS. 
    • Good time to wake a cardiologist. 
  17. 2nd Degree Heart Block Type II
    Another look. 
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    • Always caused by bad stuff. 
  18. Third degree heart block aka
    AV dissociation
    Complete heart Block
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    • Atrial rate (P wave) is regular
    • Ventricular Rate (QRS) is regular, but...
    • ...Atrial and Ventricular rates are not in sync. 
Card Set
Cardiac Rhythms and Rhythm Disturbances (Ventricular Tachy-Blocks)
Adult MedSurg 2