Flashcards in Cardiac Rhythm Disturbances (Johsnton) Deck (51):
What drugs/electrolytes are associated with bradycardia?
Digitalis, quinidine, hyperK
Drugs used for HTN to inhibit sympathetic tone --> clonidine, methyldopa, reserpine
HR __ with inspiration
HR __ with expiration
Can cause sinus arrhythmia and waxes/wanes with phases of respiration
Describe the following components of bradycardia:
P wave of sinus origin (normal axis)
Rate < 60/min
Constant and normal PR interval (.12-.20 sec)
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
To tx bradycardia with hemodynamic compromise/unstable acute situations, use:
Atropine- .3--> .5 , 1 mg--> 2 mg IV, repeate 10 min
___ is a property of a cardiac cell to depolarize spontaneously during phase 4 of action potential/leads to generation of an impulse
___ are seen in absence of significant heart disease, is associated with stress, alcohol, tobacco, coffee, COPD, and CAD
Atrial arrhythmias, PAC
Describe the QRS with a PAC with aberrant ventricular conduction
Describe the QRS in a non-conducted PAC
How can you tx PACs if symptomatic?
Metoprolol 25-50 mg BID-TID
___ is a sudden HR greater than 100, usually rate of 150-250/min
Paroxysmal Atrial Tachycardia
Identify the "irritable focus"; P' wave
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
Describe the following components of Multifocal Atrial Tachycardia:
-Amount of P waves
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
Multifocal Atrial Tachycardia is associated with:
Electrolyte abnormalities (decreased K and Mg)
How can you tx MAT?
CCB --> Non-DHP such as Diltiazem IV and Verapamil IV (avoid if EF <40%)
Caution with B blockers
What are some etiologies of sinus tachycardia?
Emotion, anxiety, fear, drugs, hyperthyroid, fever, pregnancy, anemia, CHF, hypolvolemia
Describe the following components of A Fib:
Atrial rate > 350-600/min
No discernible P waves
"Irregularly irregular" ventricular rhythm --> irregular RR interval (QRS complex)
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
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
Describe the following components in Paroxysmal Junctional Tachycardia:
P wave may be lost (buried), inverted before or after each QRS
Describe the P waves in AV Nodal Re-entrant Tachycardia
No P waves
Describe the following components of Premature Ventricular Contraction's:
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
What are some drugs/sources that can cause ventricular rhythm disturbances?
What usually happens after a premature ventricular contraction?
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
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
Describe the following components of V Tac:
-Number and characteristics of QRS complexes
-size of QRS
-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
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
What are the clinical settings of V Fib?
AMI, HF, IHD, K disturbance (low or high)
Disorganized depolarization, not effective pumping
What do you need to do if a pt goes into V Fib?
Ventricular flutter is characterized by a rate of ___ per minute, ___ waves, and can lead to this EKG pathology ___
How do you tx Torsades de Pointes?
MgSO4, 1-2 g IV bolus
What are some etiologies of HypoK?
High aldosterone (Conns, Cushings)
B agonist overdose
What are EKG characteristics of HypoK?
Flat or Inverted T wave
What are some etiologies of HyperK?
Renal failure (insufficiency)
Cell breakdown --> Hemolysis, Rhabdomyolysis
What are EKG characteristics of HyperK?
Peaked T wave
Loss of P wave
How can you tx HyperK?
Insulin and glucose
What are some etiologies of HypoCalcemia?
Chronic renal failure
Vit D deficiency
What are EKG characteristics of HypoCalcemia?
Prolongation of QT interval
What are some etiologies of HyperCalcemia?
Granulomatous disorders (TB, Sarcoidosis)
Endocrine disorders (adrenal insufficiency, hyperthyroid)
What are some EKG characteristics of HyperCalcemia?
Short QT interval
Short ST segment
What are some etiologies of HypoMagnesemia?
Renal Mg loss
What are EKG characteristics of HypoMagnesemia?
Decreased T wave
What are some etiologies of HyperMagnesemia?
Magnesium containing drugs
What type of EKG characteristic is associated with Hypothermia?
J wave (osborne wave)
What are EKG findings of a PE?
T wave inversion V1-V4
Whenever you see widespread flattening or mild inversion of T waves without associated ST segment displacement, always think of ___
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
Brugada syndrome is characterized by a RBBB with ST elevation is leads ___ . What are these folks susceptible to?
V1, V2, V3
Describe the following in Wolff-Parkinson-White syndrome (WPW):
Short PR interval
Slurred upstroke (DELTA WAVE) of QRS complex
Accessory AV conduction pathway (bundle of kent)