Class 7 Deck 2 Flashcards
What is adenosine MOA
-Activates K channels that hyperpolarize nodal tissue causing transient 3rd degree block
What drug inhibits the action of adensoine
-Methylxanthines
What are the indication for adenosine?
- PSVT
- No effect on arrhythmias originating distal to AV node
Adenosine toxicity
- Facial flushing
- Dyspnea
- Chest pressure
- Exacerbate bronchoconstriction in asthma
What is Prodysrhythmic Effects?
-New Brady or Tachy arrhythmias associated with chronic antidysrhythmias drug treatment
A K channel blockade may do what?
-Prolong QT causing polymorphic Vtach or VFib
What 2 classes of antidysrhythmic meds may block K channels and prolong QT?
- Class 1A
- Class 3
How to treat torsades
- Correct electrolytes
- Mag 2 grams
- Increase HR w/ temp pacing or isoprotenerol
- Cardiovert if hemodynamically unstable
Incessant ventricular tachycardia is precipitated by what 2 antiarryhthmic drug classes?
-Class 1A and 1C (drugs that slow conduction of cardiac impulses)
Wide complex ventricular rhythm is associated with what antiarryhthmic drug class and in what setting?
-Class 1C w/ structural heart disease
What are the 3 treatment goals for antiarrhythmic drugs?
- Restore NSR
- Abolish ectopic beats
- Control HR
What are the easy fixes when treating arrhythmias?
- Hypoxia
- Hypercarbia
- Acidosis/Alkalosis
- Electrolyte imbalance
- Temp
What inhalational agent sensitizes myocardium to catecholamines that can lead to ventricular arrhythmias?
-Halothane
How do inhalation agents effect cardiac rhythms?
-Affect conduction and cause junctional rhythms
What 2 muscle relaxants are vagolytic?
- Pancuronium
- Gallamine
Repeated doses of succs can lead to what types of arrhythmias?
- SB
- Junctional
- Ventricular arrhhythmias
- Asystole
What may be the first sign of myocardial ischemia?
- PVC’s
- Changes in conduction
What are 6 therapeutic alternatives to help slow the heart?
- Treat underlying cause
- Increase anesthetic depth
- Vagal maneuvers
- Drugs
- Overdrive pacing
- DC shock
What are 6 therapeutic alternatives to help increase heart rate?
- Stop manipulation
- Atropine
- Pancuronium / gallamine
- Isoproterenol
- Ephedrine
- Pacing
Intraop brady can be treated with what?
- Lighten anesthesia
- Anticholinergic (glyco/atropine)
- Beta agonist (isoproterenol/ephedrine)
- Pacemaker
How should intraop SVTs be treated?
- Cardioversion if SBP is <80
- Focus on reversible causes
- Adenosine (PSVT)
- Procainamide (WPW)
What drugs should be avoided in SVTs and why?
- Class 2 & 4 (AV nodal blocking)
- Induce VF
AFib /Flutter should be treated how?
- Control ventricular rate using:
- Class 2&4 (AV nodal blockers)
- Esmolol/propanolol
- Diltiazem/Verapamil
- Tensilon/Neostigmine
- Digoxin (CHF)
- Vagal/overdrive pacing/DC cardioversion
What class of drugs are more likely to terminate Afib/flutter?
- Class 1A (procainamide)
- Class 3 (Amiodarone)
What 2 meds may be prior to DC cardioversion to help maintain sustained cardioversion?
- Procainamide
- Amiodarone
How to treat sustained VT or VF?
- Lidocaine / Procainamide
- Amiodarone
How to treat polymorphic VT
-Asynchronous DC countershocks
How to prevent further polymorphic VT
- Mag
- K
- Increase HR
- Class 1B (lidocaine/phenytoin)
