Cardiac Rhythm Disturbances (Johsnton) Flashcards Preview

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Flashcards in Cardiac Rhythm Disturbances (Johsnton) Deck (51):
1

What drugs/electrolytes are associated with bradycardia?

Digitalis, quinidine, hyperK
Drugs used for HTN to inhibit sympathetic tone --> clonidine, methyldopa, reserpine
B blockers

2

HR __ with inspiration

HR __ with expiration

Increases

Decreases

Can cause sinus arrhythmia and waxes/wanes with phases of respiration

3

Describe the following components of bradycardia:

-P wave:
-Rate:
-PR interval

P wave of sinus origin (normal axis)
Rate < 60/min
Constant and normal PR interval (.12-.20 sec)

4

Sinus bradycardia is commonly seen in ___, especially in the 1st few hrs. This is related to sinus node ischemia or to a vagal reflex initiated in ischemic area

Acute inferior MI

5

To tx bradycardia with hemodynamic compromise/unstable acute situations, use:

Atropine- .3--> .5 , 1 mg--> 2 mg IV, repeate 10 min

6

___ is a property of a cardiac cell to depolarize spontaneously during phase 4 of action potential/leads to generation of an impulse

Automaticity

7

___ are seen in absence of significant heart disease, is associated with stress, alcohol, tobacco, coffee, COPD, and CAD

Atrial arrhythmias, PAC

8

Describe the QRS with a PAC with aberrant ventricular conduction

Wide QRS

9

Describe the QRS in a non-conducted PAC

No QRS

10

How can you tx PACs if symptomatic?

Reverse causes
Beta blocker
Metoprolol 25-50 mg BID-TID

11

___ is a sudden HR greater than 100, usually rate of 150-250/min

Paroxysmal Atrial Tachycardia

Identify the "irritable focus"; P' wave

12

In PAT with AV block, you will have ___ P' wave/QRS complex and should suspect ___ toxicity

2 P' waves for each QRS (2:1 ratio of P':QRS) --> rapid rate, spiked P' waves

Digitalis

13

Describe the following components of Multifocal Atrial Tachycardia:

-Amount of P waves
-PR interval
-Ventricular rhythm
-Atrial rate

3 or more different P waves
PR interval varies
Irregular ventricular rhythm
Atrial rate > 100

Should see at least 3 consecutive P waves with varying morphologies present with a rate over 100/min

14

Multifocal Atrial Tachycardia is associated with:

COPD/pneumonia/Ventilator theophylline
Beta agonists
Electrolyte abnormalities (decreased K and Mg)
Digitalis toxicity
Sepsis

15

How can you tx MAT?

CCB --> Non-DHP such as Diltiazem IV and Verapamil IV (avoid if EF <40%)
MgSO4 IV

Caution with B blockers

16

What are some etiologies of sinus tachycardia?

Emotion, anxiety, fear, drugs, hyperthyroid, fever, pregnancy, anemia, CHF, hypolvolemia

Physiologic/pathologic process

17

Describe the following components of A Fib:

-Atrial rate
-Baseline
-P waves
-ventricular rhythm

Atrial rate > 350-600/min
Undulating baseline
No discernible P waves
"Irregularly irregular" ventricular rhythm --> irregular RR interval (QRS complex)

18

What does A flutter look like on EKG? Which leads are they often best seen? Whats the rate>

"Saw tooth appearance"

Leads II, III, aVF, V, often best leads

250-350/min

19

A junctional automaticity focus may cause retrograde atrial depolarization. What does each P' wave look like in leads with an upright QRS?

Inverted P' waves

20

Describe the following components in Paroxysmal Junctional Tachycardia:

-Rate
-P waves

Rate 150-250/min
P wave may be lost (buried), inverted before or after each QRS

21

Describe the P waves in AV Nodal Re-entrant Tachycardia

No P waves

22

Describe the following components of Premature Ventricular Contraction's:

-QRS complex
-P wave

Premature, bizarre, Wide QRS
No preceding P wave; may produced a retrograde P wave in ST segment

The ST-T wave moves in opposite direction of QRS
Usually full compensatory pause

23

What are some drugs/sources that can cause ventricular rhythm disturbances?

Nicotine
Caffeine
Thyroid
Aminophylline
Digitalis intoxication

24

What usually happens after a premature ventricular contraction?

Compensatory pause

25

How do you tx PVCs if the pt is stable?

If stable, no Rx; if symptomatic or in setting of ACS-Metoprolol (B blocker) 2.5-10 mg IV

26

How do you tx a PVC in an unstable pt?

If unstable-Amiodarone, Lidocaine (1-1.5 mg/kg up to 3 mg/kg), Procainamide

27

Describe the following components of V Tac:

-Number and characteristics of QRS complexes
-Ventircular rate
-size of QRS
-P wave
-How long they last

3 or more consecutive bizarre QRS complexes
Ventricular rate 120-200 (100-250)
Usually regular, Wide QRS (>.12 sec)
P wave often lost; if seen no relationship to QRS (AV dissociation)
Lasts longer than 30 seconds (sustained)

Can have fusion beats (Dressler) and capture beats

28

A 63 y/o man has been in the ED for 90 mins with a hx of chest pain. The EKG reveals an acute anterior wall infarction and V Tac. He becomes suddenly cool, clammy, and confused with a systolic BP of 70. What do you do?

Cardioversion d/t sudden change in clinical status

29

What are the clinical settings of V Fib?

AMI, HF, IHD, K disturbance (low or high)

Disorganized depolarization, not effective pumping

30

What do you need to do if a pt goes into V Fib?

CPR, Defibrillation

31

Ventricular flutter is characterized by a rate of ___ per minute, ___ waves, and can lead to this EKG pathology ___

250-350

Sine

V Fib

32

How do you tx Torsades de Pointes?

MgSO4, 1-2 g IV bolus
Overdrive pacing
Isoproternol

33

What are some etiologies of HypoK?

Diuretics
Metabolic alkalosis
High aldosterone (Conns, Cushings)
B agonist overdose
Diarrhea
Renal loss

34

What are EKG characteristics of HypoK?

U waves
Flat or Inverted T wave

35

What are some etiologies of HyperK?

Renal failure (insufficiency)
Metabolic acidosis
DKA
Cell breakdown --> Hemolysis, Rhabdomyolysis

36

What are EKG characteristics of HyperK?

Peaked T wave
Wide QRS
Loss of P wave

37

How can you tx HyperK?

Dialysis
Insulin and glucose
NaHCO3
Albuterol
Resin-binding agents

38

What are some etiologies of HypoCalcemia?

Chronic renal failure
Vit D deficiency
Hypoparathyroidism
Acute pancreatitis
Hypomagnesium

39

What are EKG characteristics of HypoCalcemia?

Prolongation of QT interval

40

What are some etiologies of HyperCalcemia?

Hyperparathyroidism
Malignancy
Granulomatous disorders (TB, Sarcoidosis)
Endocrine disorders (adrenal insufficiency, hyperthyroid)

41

What are some EKG characteristics of HyperCalcemia?

Short QT interval
Short ST segment

42

What are some etiologies of HypoMagnesemia?

Poor nutrition
Alcoholism
Decreased absorption
Renal Mg loss
Diuretics

43

What are EKG characteristics of HypoMagnesemia?

Prolonged PR
Wide QRS
Prolonged QT
Decreased T wave

44

What are some etiologies of HyperMagnesemia?

Renal failure
Magnesium containing drugs

45

What type of EKG characteristic is associated with Hypothermia?

J wave (osborne wave)

46

What are EKG findings of a PE?

T wave inversion V1-V4
Transient RBBB

47

Whenever you see widespread flattening or mild inversion of T waves without associated ST segment displacement, always think of ___

Hypothyroidism

48

In addition to a widespread flattening or mild inversion of T waves without ST segment displacement seen in Hypothyroidism, what other constant EKG finding is seen in this condition?

Low voltage of the QRS complex

49

Brugada syndrome is characterized by a RBBB with ST elevation is leads ___ . What are these folks susceptible to?

V1, V2, V3

Deadly arrhythmias

50

Describe the following in Wolff-Parkinson-White syndrome (WPW):

-PR interval
-QRS complex
-Miscellaneous finding

Short PR interval
Slurred upstroke (DELTA WAVE) of QRS complex
Accessory AV conduction pathway (bundle of kent)

51

How do you tx Wolf-Parkinson-White syndrome?

Event recorder/monitor