See handout on amiodarone.
#1 drug for getting rid of ventricular beats.
- IVR with HR 100-150/minute
- ↓ CO symptoms
- May be pulseless
- May defibrillate or Cardiovert
- 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.
Atrial premature beats
- Typically caused by fluid overload.
- Count as HR if they perfuse.
- Premature atrial usually will perfuse.
Premature Ventricular contractions (beats)
- Will not have atrial kick or preload.
- 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.
What are these?
- 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.
What is Torsades de Pointes
(Twisting of points)
- 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.
What can cause PVCs?
- the big disease.
- Low serum K+-->worse kinds of PVCs.
What is a garret?
Weird route of electrical impulse from IVRs.
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.
What does atrial flutter look like?
- May occasionally get a QRS.
- Usually will see A-Fib, not flutter.
What does Atrial Fibrillation look like?
- 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.
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
What does 1st degree heart block look like?
- ECG will have prolonged PR interval.
- Escemic tissue between SA and AV node forces impulse to "go around."
- No symptoms and no treatment.
2nd Degree Heart Block aka
- Progressive lengthening of the PR interval, until it can not be conducted and a QRS complex is “dropped”. Cyclic patterned and considered stable.
2nd Degree Heart Block Type II, aka
Classic 2nd Degree
- 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.
2nd Degree Heart Block Type II
- Always caused by bad stuff.
Third degree heart block aka
Complete heart Block
- Atrial rate (P wave) is regular
- Ventricular Rate (QRS) is regular, but...
- ...Atrial and Ventricular rates are not in sync.