Arrhythmias

Question 1

Volatile anesthetics can produce an arrythmia through what?

Answer 1

A re-entrant mechanism

Question 2

What is PEA?

Answer 2

An organized rhythm without a pulse except for v fib, v tach, or asystole

Question 3

H’s and T’s for Asystole and PEA:

6H’s and 5T’s

Answer 3

Hypovolemia
Hypoxia
Hydrogen Ions (acidosis) 
Hyper and hypokalemia 
Hypoglycemia 
Hypothermia 
Toxins/tablets 
Tamponade (cardiac) 
Tension PTX 
Thrombosis 
Trauma

Question 4

What’s your plan of action for Asystole and PEA?

Answer 4

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

Question 5

Bradycardia is :

Causes of bradycardia:

Answer 5

less than 60 bpm or less than 50 bpm in patients on beta blocker therapy
Causes: hypoxia/hypercarbia, acidosis, drug effects

Question 6

What’s your game plan for bradycardia:

Answer 6

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

Question 7

Causes of tachycardia:

Answer 7

Hypoxia/hypercapnia
Pain/anxiety
Inadequate anesthesia
hypovolemia/anemia

Question 8

What’s your game plan for stable tachycardia?

Answer 8

check all vital signs
check EKG 
Check baseline HR 
O2 and ventilation 
Treat underlying problem 
Beta blockers in patients with underling ischemic heart disease

Question 9

What’s your game plan for unstable tachycardia?

Answer 9

Support airway, breathing, circulation 
Give Oxygen 
check all vital signs 
establish IV access 
synchronized cardioversion: 100, 200, 300 then 360 joules

Question 10

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?

Answer 10

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

Question 11

How to treat PAC?

Answer 11

Rarely needed, but Beta blockers or digoxin can be considered if heodyanmic function is impaired.

Question 12

How does digoxin work?

Answer 12

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

Question 13

What is PSVT-what’s the rhythm?
what happens to QRS?
Lacks the normal _____
What is it associated with?

Answer 13

Rapid, regular rhythm
Narrow QRS complex
Lacks normal sinoatrial node P wave
Associated with WPW, PE, Intrinsic heart disease

Question 14

What’s your treatment plan for PSVT?

Answer 14

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

Question 15

For atrial flutter: is rhythm regular?
Is QRS complex normal?
What are causes?

Answer 15

Regular rhythm
QRS is normal
Causes: severe heart disease, hyperthyroidism, mitral valve disease

Question 16

Tx for atrial flutter if hemodynamically stable:

Answer 16

Stable: Pharmacologic or synchronized cardioversion AFTER ruling out the risk of thromboembolic event
Beta blockers like esmolol or propranolol
CCB lik verapamil or dilt

Question 17

Tx for atrial flutter if hemodynamically UNstable?

Answer 17

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

Question 18

Atrial fib: are P waves there? is QRS normal

Answer 18

no p waves

qrs is normal

Question 19

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?

Answer 19

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.

Question 20

What are junctional rhythms?
what do the P waves look like?
Is the rhythm regular?
Is the QRS complex normal?

Answer 20

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

Question 21

Treatment for junctional rhythm:

Answer 21

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

Question 22

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?

Answer 22

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

Question 23

What’s your treatment plan for PVCS?

Answer 23

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

Question 24

V tachycardia: What is it?

Answer 24

The presence of 3 or more PVCs

The presence of a fusion beat, capture beat, and AV dissociation

Question 25

What is your treatment plan for V tach with a pulse?

Answer 25

AMiodarone 150 mg IV infusion over 10 minutes

Synchronized cardioversion: start with 100-200 joules, then 300 joules, then 360 joules

Question 26

V fib: what is the definition? What are causes?

Answer 26

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

Question 27

Plan for pulseless VT and V fib:

Answer 27

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

Question 28

Torsaddes: Any atrial component?
P wave?
Why does it happen?
How do you treat it?

Answer 28

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