Arrhythmias Flashcards
Volatile anesthetics can produce an arrythmia through what?
A re-entrant mechanism
What is PEA?
An organized rhythm without a pulse except for v fib, v tach, or asystole
H’s and T’s for Asystole and PEA:
6H’s and 5T’s
Hypovolemia Hypoxia Hydrogen Ions (acidosis) Hyper and hypokalemia Hypoglycemia Hypothermia Toxins/tablets Tamponade (cardiac) Tension PTX Thrombosis Trauma
What’s your plan of action for Asystole and PEA?
Call for help CPR Oxygen Attach the monitor/defibrillator Resume CPR Epi 1 mg IV or IO may repeat every 3-5 min OR one dose of vasopressin 40 units IV/IO Atropine 1 mg IV or IO may repeat every 3-5 min if PEA rate is slow Look for underlying cause No defibrillation
Bradycardia is :
Causes of bradycardia:
less than 60 bpm or less than 50 bpm in patients on beta blocker therapy
Causes: hypoxia/hypercarbia, acidosis, drug effects
What’s your game plan for bradycardia:
Check all vital signs
check baseline HR
Ensure secure airway with adequate oxygenation and ventilation
obtain 12 lead EKG
Tx recommended for hypotension, ventricular arrhythmias, or signs fo poor peripheral perfusion
That tx: Atropine 0.5-1.0 mg IV bolus repeated every 3-5 min up to 0.04 mg/kg
Ephedrine 5-10 mg
Dopamine 5-20 mcg/kg/min infusion
isoproterenol 2-10 mcg/kg/min infusion
Temporary transcutaneous pacing or transvenous pacemaker should be done immediaely if patient is symptomatic
Causes of tachycardia:
Hypoxia/hypercapnia
Pain/anxiety
Inadequate anesthesia
hypovolemia/anemia
What’s your game plan for stable tachycardia?
check all vital signs check EKG Check baseline HR O2 and ventilation Treat underlying problem Beta blockers in patients with underling ischemic heart disease
What’s your game plan for unstable tachycardia?
Support airway, breathing, circulation Give Oxygen check all vital signs establish IV access synchronized cardioversion: 100, 200, 300 then 360 joules
What is the cause of PAC? what happens to the P wave? What happens to PR interval Is there a pause? Is the rhythm regular?
ectopic pacemaker site in left or right atrium P wave will have different shape PR interval will vary normal sinus cycle with no pause rhythm is irregular
How to treat PAC?
Rarely needed, but Beta blockers or digoxin can be considered if heodyanmic function is impaired.
How does digoxin work?
Digoxin induces an increase in intracellular sodium that will drive an influx of calcium in the heart and cause an increase in contractility. Reversibly inhibits the Na-K ATPase enzyme
What is PSVT-what’s the rhythm?
what happens to QRS?
Lacks the normal _____
What is it associated with?
Rapid, regular rhythm
Narrow QRS complex
Lacks normal sinoatrial node P wave
Associated with WPW, PE, Intrinsic heart disease
What’s your treatment plan for PSVT?
Vagal maneuvers
Adenosine 6 mg IV rapid bolus, followed by a third dose if necessary at 12-18 mg per bolus
Verapamil 2.5-10 mg IV
Amiodarone 150 mg IV infusion over 10 minutes
Esmolol 1 mg/kg bolus
Phenylephrine if pt is hypotensive
Digoxin 0.5-1.0 mg IV
IF that still doesnt work-rapid overt pacing
synchronized cardioversion in incremental dosing: 100, 200, 300 then 360-this should be done if pt is hemodynamically UNstable
For atrial flutter: is rhythm regular?
Is QRS complex normal?
What are causes?
Regular rhythm
QRS is normal
Causes: severe heart disease, hyperthyroidism, mitral valve disease
Tx for atrial flutter if hemodynamically stable:
Stable: Pharmacologic or synchronized cardioversion AFTER ruling out the risk of thromboembolic event
Beta blockers like esmolol or propranolol
CCB lik verapamil or dilt
Tx for atrial flutter if hemodynamically UNstable?
Synchronized CV with 100, 200, 300, 360 joules if needed
Procainamide 5-10 mg/kg IV loading dose iwht 0.5 mg/kg/minute infusion-sodium channel blocker
Atrial fib: are P waves there? is QRS normal
no p waves
qrs is normal
Acute a fib: whats your plan? What if it’s been present for over 48 hours?
How long should AC be going for prior to cardioversion if thrombus is present?
IV dilt or esmolol
Can do synchronized CV in pts with pornounced hemodynamic instability: 100-200 joules, then 300, then 360
If it’s been present for over 48 hours, then there is an increased risk of thromboembolism.
AC for 3-4 weeks should be considered prior to cardioversion if a thrombus is present.
What are junctional rhythms?
what do the P waves look like?
Is the rhythm regular?
Is the QRS complex normal?
Ectopic activity initiated by sites just superior or inferior to AV node (AV node can NOT act as a pacemaker)
P waves are abnormal
Regular rhythm
QRS complex is normal
Treatment for junctional rhythm:
Usually requires no tx, but if pt becomes hypotensive and has poor perfusion, treatment is indicated. Amiodarone is drug of choice. IV atropine, ephedrine, or isoprterenol can be used in an effort to decrease activity of AV node Small dose (10 mg of succinylcholine) can possibly revert nodal rhythm to sinus
PVCs-why do they happen and why is this significant?
What does the QRS look like?
Is there a P wave?
What’s the rhythm?
Ectopic pacemaker activity arising inferior to AV junction. Causes: common during anesthesia, especially with underlying cardiac disease. Electrolyte and blood gas abnormalities. Significant be cause it can progress to v tach or v fib
Wide QRS complex
No p wave
Rhythm is irregular
What’s your treatment plan for PVCS?
correct underlying abnormality (decreased serum potassium or low arterial oxygen tension ), check blood gas, electroytes, EKG and possibl x ray.
If greater than 3 per minute, assess why
If greater than 6 per minute, administer lidocaine at 1.5 mg/kg IV bolus
recurrent PVCs can be given esmolol, or atropine
V tachycardia: What is it?
The presence of 3 or more PVCs
The presence of a fusion beat, capture beat, and AV dissociation
What is your treatment plan for V tach with a pulse?
AMiodarone 150 mg IV infusion over 10 minutes
Synchronized cardioversion: start with 100-200 joules, then 300 joules, then 360 joules
V fib: what is the definition? What are causes?
irregular rhyth with erratic ventricular contractions-bizzarre pattern of various sizes. P waves are NOT visible, rapid, grossly disorganized rhythm. NO QRS
Causes: H’s and T’s: hypoxia, hypothermia, myocardial ischemia
Plan for pulseless VT and V fib:
CPR
Oxygen
Attach the monitors/defibrillator
Asynchronous defibrillation (one shock with 120-200) joules for biphasic defibrillator or 360 joules for a monophasic defibrillator
Resume CPR
Continue to alternate one shock and CPR as long as patient maintains a shockable rhythm
Once patient has an IV, give epinephrine 1 mg IV/IO (may repeat 3-5 minutes) or vasopressin 40 units IV/IO
Consider an anti-arrythmic such as:
Amiodarone 300 then additional dose of 150
Magnesium 1-2 grams IV for torsades
After 5 cycles of CPR/shock, re-evaluate rhythm
Torsaddes: Any atrial component?
P wave?
Why does it happen?
How do you treat it?
No atrial component
P wave buried in QRS
Occurs in presence of disturbed repolarization: prolonged QT
TX: d/c drugs that led to prolonged QT and correct electrolyte abnormality
asynchronous defib
1-2 g mg sulfate
