Arrhythmias

Question 0

First degree AV block

-ECG, associations, treatment

Answer 0

ECG: PR > 200
a/w increased vagal tone or B-block/CCB use
Tx: none

Question 1

List of bradyarrhythmias

Answer 1

Sinus bradycardia
AV block: first degree, second degree Mobitz I (aka Wenckebach), second degree Mobitz II, third degree
Sick sinus syndrome (aka tachy-brady syndrome)

Question 2

Wenckebach

Answer 2

Second degree AV block, Mobitz I

Question 3

Etiologies of Mobitz I AV block

Answer 3

Drug effects: digoxin, B-blockers, CCB
Increased vagal tone
Right coronary ischemia or infarction -> RCA is blood supply for AV node

Question 4

Mobitz I vs Mobitz II

Answer 4

I: progressive PR lengthening until a dropped beat occurs
II: unexpected dropped beats without a change in PR interval

I is intranodal while II is below AV node
Only tx for I is atropine while II needs pacemaker placement

Question 5

EKG of third degree AV block

Answer 5

No relationship between P waves and QRS complexes

Question 6

Si/sx of third degree AV block and tx

Answer 6

Syncope, dizziness, acute heart failure, hypotension, cannon A waves

Tx: pacemaker placement

Question 7

cannon A waves

Answer 7

Third degree AV block

Question 8

List of supraventricular tachyarrhythmias

Answer 8

Sinus tachycardia, atrial fibrillation, atrial flutter, multifocal atrial tachycardia, AVNRT, AVRT, and paroxysmal atrial tachycardia

Question 9

Etiology of acute and chronic atrial fibrillation

Answer 9

Acute: PIRATES
-pulmonary dz, ischemia, rheumatic heart disease, anemia/atrial myxoma, thyrotoxicosis (classic step 2 question), ethanol, sepsis

Chronic: HTN, CHF

Question 10

Tx of a-fib

Answer 10

A-fib < 48 hours can just be cardioverted

A-fib > 48 hours requires an echo or 3-6 weeks of anticoagulation

Question 11

CHADS2 score

Answer 11

CHF
HTN
Age > 75
Diabetes
Stroke = 2 points

2 or more points = requires warfarin

Question 12

Digoxin and a-fib

Answer 12

Rate control > rhythm control
Digoxin is used to slow the resting heart rate and is rarely given by itself
-usually with CCB or b-blocker

Question 13

DKG of a-flutter

Answer 13

Sawtooth pattern: multiple P waves before every QRS

Can calculate what percentage is

Question 14

Multifocal atrial tachycardia

-etiology, EKG, Tx

Answer 14

Etiology: multiple atrial pacemakers or reentrant pathways; COPD; hypoxemia

EKG: at least 3 different P wave morphologies; each P wave from different foci

• more than 3 P waves w/ HR< 100 = wandering pacemaker
• more than 3 P waves w/ HR < 60 multifocal atrial bradycardia

Question 15

Multifocal atrial tachyardia treatment

Answer 15

Underlying disorder

Rate control: verapamil or B-blockers

Question 16

AVNRT definition

Answer 16

A reentrant circuit in the AV node
-you have a slow and a fast pathway in the AV node which will lead to a re-entrant circuit in the node itself

Rate: 150-200 bpm, P waves often get buried in QRS complex

Tx: cardiovert if unstable; carotid massage; valsalva, adenosine

Question 17

AVRT definition

Answer 17

Reentrant circuit of the heart outside the AV node
most common ex: Wolff-Parkinson-White syndrome

ECG: retrograde P wave after a normal QRS
-preexcitation delta is common in WPW (upstroke just before QRS starts)

Tx: cardiovert
-note: cannot give adenosine for WPW syndrome (since it’s not a nodal problem); use amiodarone or procainamide instead

Definite therapy: catheter ablation

Question 18

Paroxysmal atrial tachycardia

Answer 18

Rapid ectopic pacemaker in the atrium (not the SA nose)
Rate > 200 bpm; P wave with an unusual axis before each normal QRS

Never pathologica, no tx needed

Question 19

List of ventricular tachyarrhythmias

Answer 19

PVC
ventricular tachycardia
ventricular fibrillation
TdP

Question 20

PVC associations

Answer 20

hypoxia, electrolyte abnormalities, hyperthyroidism, caffine

Question 21

V-tach definition

Answer 21

> 3 PVCs in a row is considered v-tach

Question 22

Ventricular tachycardia associations

Answer 22

CAD, MI, structural heart disease; wide QRS in a regular rapid rhythm

Question 23

Tx for v-tach

Answer 23

Can progress to v-fib if untreated

Cardiovert and antiarrhythmics, namely procainamide, lidocaine, and amiodarone

Question 24

V-fib signs and symptoms

Answer 24

Syncope, absence of blood pressure, pulselessness

Question 25

TdP associations and tx

Answer 25

a/w long QT syndrome, proarrhythmic response to medications, hypokalemia, congenital deafness, and alcoholism

EKG: polymorphous QRS

Tx: magnesium and cardiovert if unstable; correct hypokalemia; withdraw offending drugs