ECG

Question 1

Answer 1

Stress Induced Myocardial Ischemia

• inc. O2 consumption with inability to inc. coronary flow appropriately
• depression of ST segment

Question 2

Answer 2

Ischemia- Acute Coronary Syndrome

• ischemia due to acute coronary artery obstruction during low oxygen demand causes T wave inversion

Question 3

Answer 3

Transmural Infarct

• ST elevation
• Q wave

Question 4

Answer 4

Evolving Transmural Myocardial Infarct

• peaked T wave
• T wave inversion
• ST elevation
• Q wave, ST elevation, T inversion

Question 5

Answer 5

Subendocardial Infarct

• ST depression
• no Q wave

Question 6

• shortened QT interval

Answer 6

Hypercalcemia

Question 7

• prolonged QT interval

Answer 7

Hypocalcemia

Question 8

• S and T waves broaden in sine wave pattern

Answer 8

Hyperkalemia

• P & R waves gone
• S & T waves broaden in sine wave pattern

Question 9

• T wave merging with U wave

Answer 9

Hypokalemia

Question 10

• big R waves in L sided leads (I, aVL, v5, v6)
• normal QRS duration with extremely high voltage

Answer 10

Left Ventricular Hypertrophy

Question 11

• big R waves in R sided leads (v1, v2)

Answer 11

Right Ventricular Hypertrophy

Question 12

Limb Leads

Answer 12

Lateral Leads

• aVL/aVR
• I

Inferior Leads

• II, III, aVF

Bipolar

• I, II, III
• (standard limb leads)

Unipolar

• aVR, aVL, aVG
• augmented limb leads

Question 13

Polarity

Answer 13

• depolarization moving toward a positive electrode produces a positive electrode
• QRS will be upright (+) in L and lateral leads
• QRS will be downward (-) in R sided leads

Question 14

• regular, fast HR (>100)
• P waves precede QRS

Answer 14

Sinus Tachycardia

Sympathetic Activation

• exercise, emotion, hypotension, resonse to actue lung or abdominal patholgy, thyrotoxicosis

Treatment

• usually none, bea blockers in thyrotoxicosis

Question 15

• regular, slow HR (<60)
• P waves precede each QRS

Answer 15

Sinus Bradycardia

• athletes
• vagotonic states: faint
• treatment: none, atropine, pacemaker if sx

Question 16

• PR interval prolonged

Answer 16

First Degree AV Block

• causes: drug induced, conduction system disease
• usually benign
• PR interval prolonged (inc. junctional delay)

Question 17

• some P waves conduct but some do not

Answer 17

Second Degree Heart Block

• Mobitz 1/Wenchebach
  
  • progressive lengthening of PR interval followed by non conducted P wave
• Mobitz 2
  
  • intermittently dropped ventricular beats preceded by constant PR intervals

Question 18

• no relationship between P waves and QRS

Answer 18

Third Degree Heart Block

• P waves at faster rate the QRS
• serious condition
• causes
  
  • severe conduction system disease
  • rarely drugs
• tx
  
  • pacing if ventricular rate or BP are too low

Question 19

• early beat often preceded by an abnormal P wave
• narrow QRS resembling normally conducted beats usually

Answer 19

Premature Atrial Contraction

Question 20

• wide QRS, no P wave
• common in normal subjects, acute MI, and heart failure

Answer 20

Premature Ventricular Contractions

• tx: usually not required, beta blockers

Question 21

• P waves at rate of 240-320 beats/min
• pulse may be regular or irregular
• ventricular rates vary widely

Answer 21

Atrial Flutter

• tx:
  
  • anticoagulation
  • rate control with drugs
  • cardioversion
  • ablation- curative

Question 22

• rapid HR
• narrow QRS
• P waves present but abnormal

Answer 22

Atrial Tachycardia

• tx:
  
  • adenosine
  • vagal maneuver
  • beta blocker
  • verapamil or diltiazem

Question 23

• no P waves
• undulating baseline
• irregularly irregular ventricular rhythm

Answer 23

Atrial Fibrillation

• causes
  
  • hyperthyroidism
  • heart disease
  • post-op
  • aging
  • hypertension (most common)
• tx
  
  • anticoagulation
  • rate control with drugs
    
    • beta blockers
    • digoxin
    • verapril
    • diltiazem
    • amiodarone
  • cardioversion (rhythm control)
    
    • class 3 agents (ibutilide, amiodarone, dofetilide, sotalol)
    • class 1C agents (flecainide, propafenone)
  • ablation
  • shick

Question 24

• regular, narrow QRS
• no antecedent P waves

Answer 24

Junctional Rhythm

• tx usually unnecessary

Question 25

* regular, wide complexes (100-200/min) * in most cases no P wave visible * termed sustained if longer than 30 sec * often life threatening

Answer 25

Ventricular Tachycardia * tx: * amidarone * lidocaine * cardioversion

Question 26

* wavy, irregular baseline * life threatening

Answer 26

Ventricular Fibrillation

Question 27

Answer 27

Asystole

Question 28

P Wave Abnormalitites in Sinus Rhythm

Answer 28

Question 29

* widened QRS with terminal WRS * upright (+) in R sided leads * downward (-) in L sided leads

Answer 29

RIght Bundle Branch Block

Question 30

* widened QRS away from v1 and towards v6

Answer 30

Left Bundle Branch Block

Question 31

* axis shift without widening the QRS

Answer 31

Hemiblock

Question 32

* ST elevations and Q waves in inferior leads (II, III, aVF) * reciprocal ST depressions in anterior leads

Answer 32

Acute Inferior MI

Question 33

* ST elevations and Q waves in anterior leads (v1-v4)

Answer 33

Acute Anterior MI

Question 34

* diffuse ST elevations in multiple leads: no localization

Answer 34

Acute Pericarditis

Question 35

* QRS positive in lead I * QRS negative in lead II

Answer 35

Left Axis Deviation