Deadly Arrhythmias

Question 1

What signs and symptoms are helpful in evaluating stability in a pt with dysrhythmia?

Answer 1

Hypotension
Hypoperfusion
Altered mental status
Ischemic chest pain
Respiratory distress
Heart rate > 300

Question 2

What life-threatening rhythm can develop from tachycardias with rates approaching 300 and why?

Answer 2

Faster rate leads to closer T and R waves that can produce R on T phenomenon that can lead to V-fib

Question 3

80% of bradyarrhythmias are caused by what?

Answer 3

Factors external to the cardiac conduction system including: ACS, hypoxia, tox, hypoperfusion, electrolyte disturbance

Question 4

What are the most common bradyarrhythmias with ACS?

Answer 4

Sinus bradycardia and AV block

Question 5

What are the drugs used for general bradycardia management and their doses?

Answer 5

Atropine: 0.5–1mg, q3–5min, max 3mg (kids 0.02mg/kg)
Glucagon: 2–10mg IV bolus
Adrenergic agents can be used but can worsen ischemia and are only a bridge to more definitive therapy. These include: dopamine, epinephrine, isoproterenol

Question 6

What is often the definitive management of bradyarrhythmias?

Answer 6

Pacing

Question 7

What site is preferred for placement of trans-venous pacer and why?

Answer 7

Right IJ to leave the left side for a permanent pacer

Question 8

Sinus bradycardia is a common presentation of what ACS region of cardiac ischemia?

Answer 8

Inferior wall MI

Question 9

Is atropine indicated when treating bradycardia secondary to MI?

Answer 9

Yes, and should be considered early in patients with symptomatic bradycardia from MI

Question 10

What bradyarrhythmias respond best to atropine?

Answer 10

Sinus bradycardia responds best, but AV blockade can also be treated with atropine

Question 11

What are common causes of a junctional rhythm?

Answer 11

ACS, Tox, or normal in trained athletes

Question 12

What is the first intervention for symptomatic junction bradycardia while attempting to find and treat the underlying cause?

Answer 12

Atropine
More likely to work if rhythm is from the AV node or from ACS
Less likely to work if lower than the AV node (Bundle of His) or from tox cause

Question 13

What is the management for unstable idioventricular rhythms?

Answer 13

Atropine is less likely to work and pacing are more likely to be required
Additionally, O2, IVF, and sufficient perfusion are key in these patients

Question 14

When should 1st degree heart block and 2nd degree type 1 heart block be taken a little more seriously?

Answer 14

Symptomatic, or:
Presence of ACS, metabolic issues, on cardiac meds that may be causing the blocks, and new onset in these scenarios as they may transition to complete heart block

Question 15

Which heart blocks should always be considered pathologic?

Answer 15

Second degree type II and third degree

Question 16

How are heart blocks related to STEMI?

Answer 16

High grade heart blocks are frequently seen in STEMI and 3rd degree blocks are predictive of STEMI in chest pain patients

Question 17

What is the difference between Type I and Type II second degree blocks?

Answer 17

Type I: Wenckebach, progressively lengthening PR, lower grade block
Type II: Fixed PR interval with occasional dropped beat, higher grade and more concerning

Question 18

How well does atropine work for AV nodal blocks?

Answer 18

Not very well

Question 19

What is the treatment for symptomatic heart block?

Answer 19

Pacing until definitive care by a cardiologist

At least place the pads on the patient