Arrhythmias

Question 1

Normal sinus rate and normal PR interval

Answer 1

sinus rate= 60-100bpm. PR= 0.12-0.20

Question 2

Requirements of normal sinus rhythm

Answer 2

P wave preceeds each QRS, with normal PR interval, rate is 60-100bpm, QRS is regular or varies slightly

Question 3

Sinus tachycardia EKG and response to carotid sinus massage

Answer 3

normal P and QRS, regular and fast HR (100-180BPM). Atrial rate may slow in response to massage

Question 4

Causes of sinus tachycardia

Answer 4

Exercise, emotion, hypotension, acute lung or abdominal pathology, thyrotoxicosis

Question 5

Sinus tachycardia treatment

Answer 5

usually none. B blockers in thyrotoxicosis

Question 6

Sinus Bradycardia EKG

Answer 6

Regular, slow HR (<60BPM). P waves precede QRS

Question 7

Causes of sinus bradycardia

Answer 7

Can be normal (ie. In athletes). Can produce vagotonic states (fainting, sick sinus syndrome, inferior infarct)

Question 8

Treatment of sinus bradycardia

Answer 8

None, Atropine for vasovagal events, or pacemaker if serious

Question 9

Sick sinus syndrome

Answer 9

syncope, lightheadedness or fatique in elderly patients with age-related dysfunction

Question 10

1st degree AV block EKG

Answer 10

PR interval prolonged (>0.2 seconds), increased junctional delay

Question 11

Causes of 1st degree AV block

Answer 11

Drugs (B blockers, Ca blockers, digitalis) or conduction system disease. Usually benign

Question 12

2nd degree AV block EKG

Answer 12

Some P waves conduct, others do not

Question 13

2nd degree AV block causes

Answer 13

Conduction system disease, high vagal tone, drugs

Question 14

3rd degree AV block EKG

Answer 14

P waves and QRS show regular rhythm, but at different rates, with P rate> QRS rate

Question 15

3rd degree AV block causes

Answer 15

Severe conduction system disease, drugs

Question 16

3rd degree AV block treatment

Answer 16

pacemaker

Question 17

3rd degree AV block complications

Answer 17

syncope or death

Question 18

Atrial flutter EKG and response to carotid massage

Answer 18

P waves (flutter waves)are saw toothed and at rate of 180-350BPM. Pulse maay be regular or irregular. Varied ventricular rates. AV block may increase with massage

Question 19

complications of atrial flutter

Answer 19

embolic stroke due to clot in left atrium, rapid ventricular rates

Question 20

Atrial flutter treatment

Answer 20

Anticoag, rate control with drugs, cardioversion, ablation

Question 21

Atrial fibrillation EKG

Answer 21

Irregularly irregular ventricular rhythm, No P waves

Question 22

Atrial fibrillation causes

Answer 22

lone A fib, aging, post-operative, heart disease, hyperthyroidism

Question 23

Complications of a fib

Answer 23

rapid HR (syncope, ischemia, heart failure), loss of atrial kick (HF), atrial thrombi (embolic stroke)

Question 24

A fib treatment

Answer 24

Anticoag, rate control with drugs, cardioversion, ablation

Question 25

Atrial tachycardia EKG and response to carotid sinus massage

Answer 25

rapid HR (atrial rate is 130-250BPM), narrow QRS, P waves present but abnormal. AV block may increase, doesn’t usually revert in response to masssage

Question 26

A tach treatment

Answer 26

Adenosine infusion, beta blocker, verapamil, diltiazem, ablation

Question 27

focal vs multifocal A tach

Answer 27

focal: one different P wave. Multifocal: >3 P wave shapes

Question 28

Junctional rhythm EKG

Answer 28

regular rate, narrow QRS, no antecedant P waves (P waves are usually inverted b/c they are conducted upward from the AV node rather than down fron SA node)

Question 29

What is a junctional rhythm

Answer 29

rhythms originating in the region surrounding the AV node

Question 30

Premature atrial contraction EKG

Answer 30

premature beat preceded by abnormal P wave, narrow QRS

Question 31

premature ventricular contraction EKG

Answer 31

wide, abnormal QRS with no P wave

Question 32

What is the cause of premature ventricular contraction?

Answer 32

ectopic ventricular focus conducted by the slower fibers of myocardium instead of Purkinje. Short path length blocks can also cause re-entry. Usually benign

Question 33

Ventricular tachycardia EKG

Answer 33

repetitive wide QRS with no P wave

Question 34

What causes V tach

Answer 34

ectopic ventricular focus conducted by myocytes, or long path length which permits re-entry (from fibrosis, infiltrate)

Question 35

Ventricular fibrillation

Answer 35

no visible P waves

Question 36

Torsades de pointes EKG

Answer 36

wide QRS at very rapid rate, no P wave, sinusoidal pattern

Question 37

Torsades de pointes is a form of what?

Answer 37

ventricular tachycardia (associated with long QT)