Atrial fibrillation risk factors - why do the following put someone at risk for atrial fibrillation
1. valvular disease - mitral regurgitation
2. mitral valve disease
3. MI/CAD
4. HTN/LVH
5. OSA
6. Lung Disease/COPD
7. Rheumatic heart disease
8. Increased age
9. Pre-op enlarged atrium
10. RCA stenosis
11. Low electrolytes
12. Inadequate cardiac protection intraoperativey
13. prolonged CPB time
14. Long aortic clamp time
- Leads to atrial enlargement/dilation
- leads to atrial enlargement
- can cause ischemic damage which damages hearts conduction pathway
- back flow of pressure puts pressure on AV valves - enlargement
- prolonged decreased oxygenation in the body
- decreased O2 in the body causes ischemic changes
- causes physical damage inside the heart
- decreased healing / decreased function related to age
- structural damage
- feeds atrium
- impairs cardiac function
- ischemic cardiac damage
- ischemia
- ischemia
Precursors to Postop Arrhytthmias (2)
High risk POAF patient recieve what postop
- PACs
- ST - pain, fever, anxiety, anemia
- Beta blockers
Atrial fibrillation
* Rate control options (4)
- Beta blockers (metoprolol, esmolol)
- Amiodarone
- Calcium channel blockers (dilt, verapimil)
- Digoxin (lanoxin)
Sotalol (betapace) use in Afib
* Action
* Dosing
* Monitor for
- Has BB properties, increases repolarization time
- Initially 112.5 mg IV, maintenance 112.5 to 150 mg IV BID
- Monitor for QTc prolongation and bradycardias
Ibutilide (Corvert)
* Action
* Dose
* Monitor for
- Antiarrhythmic potassium channel blocker with fewer hemodynamic side effects compared to amio
- 1mg over 10 min IV
- Monitor for prolongation of QT / torsades
Side effects of antiarrhythmics =
What are these drugs used for?
* Quinidine (cardioquin)
* Procainimide (Pronestyl)
* Lidocaine (xylocaine)
* Tocainamide (toinocard)
* mexiletin (mexitil)
* Flecainide (tambocor)
* Propafenone (rhythmol)
- Risk of QT prolongation
- ventricular dysrhythmias
What type of drugs are these?
* Amiodarone (cordarone)
* Ibutilide (corvert)
* Dofetilide (tikosyn)
* Bretylium (bretylol)
* Sotalol (Betapace)
* Verapamil (Calan)
* Digoxin (lanoxin)
* Adenosine (adenocard)
Antiarrhythmics, blocking either potassium or calcium slowing the conduction process
Calcium Channel Blockers
* indication
* Action
* Examples 2
* How to give in general and what to watch out for
- Used to treat tachyarrhythmias, HCM, angina, vasospasm
- Cardio selective and vasoselective, blocks calcium channels in the vessel wall (remember what calcium IV does)
- Verapamil (calan, Isoptin), Diltiazem (cardizem)
- Give a dose of 5-20 mg IV then start continuous infusion
- Watch out for hypotension, bradycardia, heart block and HF
Digoxin
1. Therapeutic Range of Digoxin
2. what vital are you targeting
3. Action
4. Toxicity tymptoms
- 0.5 0 2.0 ng/ml
- targeting heart rate goal
- Slows conduction of impulse through AV node while increasing myocardial contractility
- PR interval prolongation, Nausea, ST segment depression, vision changes
Atrial Flutter
* What is this thought to be an issue with
* Rate
* Symptoms
* Treatment
* Risks asoc.
- Thought to be an atrial re-entry issue
- Atrial rate 250-350
- Syncope, palpitations, fatigue, exercise intolerance, SOB, chest pain. decreased CO
- Cardioversion, anticoagulation, overdrive pacing, surgery
- Thrombus, Stroke, heart failure if prolonged
Cardioversion Safety
* Oh Say it isn’t so!
- Oxygen
- Sedation
- Intubation/airway supplies
- IV
- Synch
Atrial Overdrive Pacing
* Purpose
* Definition
- Used in attempt to terminate afib or aflutter
- Pacing the patient rapidly above their current rate for a time and is then released
Maze procedure
* Definition
* what does it have in common with overdrive pacing
- Used for treatment of Afib, incision made to left and right atrium to form scar tissue that doesn’t conduct erratic impulses to atrium
- Both treatments are hoping SA node takes over as pacer of the heart
SVT
* Treatment of Unstable vs Stable
- Unstable: Cardioversion
- Stable: VAD - Vagal maneuvers, Adenosine 6mg rapid, Diltiazem or beta blockers
Indications for Pacemaker
(permanent or temporary)
- Symptomatic Bradycardia
- 2nd degree AV block
- Third degree AV block
Atropine
* treatment for what
* action
* dose
* side effects
- Symptomatic bradycardia
- Inhibits parasympathetic nervous system
- 1.0 mg IV push q3-5 min
- Tachycardia, Dry mouth, urinary retention, demand ischemia
Transcutaneous Pacing
* Pad placement
* Settings
* Transvenous and transcutaneous pacing only use what mode
* Starting amps
- Anterior - posterior, anterior - lateral
- VVI mode only, demand pacing, start @ 50 mA and increase uintil captuire
- VVI
What do the letters mean in VVI
- V paced
- V sensed
- Inhibit pace on intrinsic rhythm
Epicardial wire removal
* Done by who
* how
* if resistance is met
* post removal monitor for
- RN or PA/NP, MD
- Aseptic technique, constant gentle traction to remove
- If resistance is met, stop. Could be stuck on graft or pt anatomy
- Monitor for Temponade, bleeding, arrhythmias
Magnet operation with PPM/ICD’
* What does the magent do
- over PPM causes asynchronous pacing at designated magnet rate
- Over ICD inhibits defib
Chest compressions
* how deep
* rate
- 2 - 2.4 inches deep
- 100 - 120 /min
Vfib or VT
* first
* cpr for how long
* rhythm check how often
* which drug and how much
* last drug
- Shock x3, shock again q2min
- cpr for 2 min
- Rhythm check Q2 min
- Epi 1 mg or Amio 300 mg
- Lidocaine if VF/VT persists
Emergency drug of choice for torsades is
Magnesium
PEA & Asystole
* Three steps
- Start compressions
- Epi 1mg q3-5 min
- Differential diagnosis with H’s and T’s
