Atrial Dysrhythmia

Question 1

What 2 major factors need to occur in order to have an atrial dysrhythmia?

Answer 1

1) A trigger that initiates the arrhythmia
- premature beats in either the atria, bundle junctions or the ventricle

2) a substrate that allow for the arrhythmia to continue
- includes infraction, ischemic tissue, scarring, fibrosis, electrolyte abnormalities, etc.

Question 2

Premature atrial complexes (PAC

Answer 2

Dysrhythmias that originate in the atrium outside of the SA node

Caused by various outside factors such as excessive caffeine, sympathetic innervation, alcohol consumption, nicotine, etc.

EKGs show a premature P wave randomly, followed by a premature QRS, and then followed by a lengthened time frame to the next P wave.

Can occur in healthy or damaged hearts

Question 3

Blocked PACs

Answer 3

Sometimes when a PAC occurs, the AV node is still in refractory period, so the signal does not get conducted (no preceding QRS but still presents a lengthened time frame to the next P wave) .

Question 4

Atrial ventricular nodal reentry tachycardia (AVNRTs)

Answer 4

Generates “dual pathways” due to reentry into the AV node for the next signal
- this is caused because the PAC fires while the normal pathway is in the refractory period

Shows a very rapid heart rate (>150bpm) with no noticeable P waves (although they are still there, just the P-waves are buried in the QRS complex)
- called retrograde P waves

Because of the retrograde p-waves, V1/V2 leads show pseudo r waves at the S wave area on the ECG

Question 5

Atrioventricular reentry tachycardia

Answer 5

AV node possess a bypass tract, usually near the left ventricle.
- makes it so the AV node is not the only conduction communication between the atria and the ventricles.

PVCs can generate their own complete heart rate rather than just ventricular beats.

Question 6

Wolff-Parkinson- white syndrome

Answer 6

A type of atrioventricular reentry tachycardia due to bundle of Kent appearance

Depicts a very short PR interval with a “delta” Q wave. (Angled and sharped Q wave with a widen QRS complex)

Question 7

Orthodromic vs antidromic

Answer 7

Orthodromic:

• signal goes down the AV node and up the bypass tract
• produces a narrow QRS (< 0.12 sec)

Antidromic:

• signal goes down bypass tract and up the AV node
• produces a wider QRS (> 0.12 sec)
• can be mistaken for V. Tachycardia

Question 8

TX of paroxysmal supraventricular tachycardia

Answer 8

Treatment revolves around increasing the refractory period of the AV node

• vagal maneuvers such as valsalva maneuver (increase parasympathetics)
• medications (outside of medications)
• adenosine specifically
• CCB’s or BB’s

cardioversion is used if nothing else works or the patient is completely unstable

Question 9

Atrial Fibrillation (AFIB)

Answer 9

MOST common arrhythmia

Causes irregular disorganized tachydysrhythmia

• QRS looks normal but the rate is unorganized and not equal
• the R waves dont have the same amplitude

High heart rate >150 bpm with super erratic not recognizable p waves that are called F waves

Can sometimes produce a rapid ventricular response (rate >100)

Question 10

Potential Causes of atrial fibrillation

Answer 10

Hyperthyroidism

Valvular heart diseases (enlarged atria)

Medications that stimulate sympathetic nervous system

PEs

Ischemic heart disease

Hypertension

Fever/anemia

Alcoholics in withdrawal

Hypothermia

Question 11

Atrial flutter vs atrial FIB

Answer 11

Atrial FIB produces random and sporadic foci in the atria where as atrial flutter usually only fires at the SA node, but the signal reenters every time

Question 12

Complications of A Fib

Answer 12

Loss of atrial kick (atrial systole pressure)

Can make heart failure or cardiomyopathies worse

Can generate atrial thrombi since blood is stagnant

Question 13

CHADS VAS score

Answer 13

Determines the stroke risk for atrial fibrillation patients

C: congestive heart failure or not? (1)

H: hypertension present or not? (1)

A: age greater than or equal to 75? (2)

D: diabetes mellitus present or not? (1)

S: prior stoke or embolism? (2)

V: any sort of history of vascular disease? (1)

A: Age between 65-74? (1)

Sc: is the patient female (1)

Question 14

Classifications of A fib based on the duration of it

Answer 14

Paroxysmal: recurrent AF that terminates spontaneously in <7days

Persistent: AF that does not disappear beyond 7 days

Long-standing: continuous AF presents for longer than 1 year

Permanent: AF lasts longer than 1 year in a patient that does not want medication to fix it.

Question 15

Does A fib and A flutter have the same Tx?

Answer 15

Yes

BB’s or CCBs are first line
- need to slow ventricular rate by increasing the refractory period of the AV node

• if patient is unstable either when presenting or taking medications, need to preform cardioversion*

Question 16

Do you control rate or rhythm first ion patients with A fib or A flutter?

Answer 16

Rate.

Question 17

Atrial flutter definition

Answer 17

Caused by an ectopic foci in the atria

Causes rapid regular atrial rates (300/min usually)

Ventricular rate can be regular or irregular

ECGs show 2-4 P waves for every QRS

• p waves are in a “sawtooth pattern”
• this is best seen in leads 2/3/AVF/V1*

Question 18

Adenosine w/ respect to atrial flutter

Answer 18

Adenosine will fix A fib, however it WILL NOT fix A flutter

- just confirms it vs A fib

Question 19

Stable vs unstable

Answer 19

Unstable =

• hypotension shock (<90mmHg systolic BP)
• goes into shock
• is confused, altered
• ischemic chest pain

Question 20

Atrial tachycardia

Answer 20

Single ectopic focus in the atria that causes a high rate of atrial beating
- p wave looks abnormal in any lead compared to the SA node lead

SUPER rare and very difficult to discern