Module 4- basic ECG & Arrhythmia

Question 1

ST Segment Elevation Myocardial Infarction

STEMI

Answer 1

Penetrates entire myocardial wall.
ST Segment elevation of 1mm or more in more than one lead that looks at the same ventricular wall segment
results in “Q” waves (wider than 1mm)

Question 2

Ventricular Flutter

Answer 2

150-300 bpm

as flutter waves become smaller, fibrillation more imminent.

Question 3

Ventricular Fibrillation

Answer 3

150-500 bpm

grossly irregular waveform with various amplitudes

Question 4

Torsade de pointes

Answer 4

type of VT showing cycles of alternation QRS polarity.

Question 5

Ventricular Tachycardia (VT)

Answer 5

3 or more Premature Ventricular Contractions occur in succession exceeding 100-250 bpm
Widened QRS complex
ST segments and T waves may not be distinct.

Question 6

Premature Ventricular Tachycardia (PVC)

Answer 6

Widened QRS (greater than .12s)
can also be interpolated
either a RBBB or LBBB or near normal morphology
-impulse of ventricular origin before next expected sinus beat, SA activity is unaffected (impulse is unable to penetrate AV node)

Question 7

3rd degree AV block

complete heart block

Answer 7

All sinus and SV impulses fail to conduct through AV node to ventricles. (Latent subsidiary pacemaker is needed)
Atrial rate is different from Ventricular rate. (no consistent PR interval)

Question 8

2nd degree AV block type II (Mobitz II)

Answer 8

Occasionally a P wave in not conducted to the ventricles.

PR interval is constant

Question 9

2nd degree AV block type I (Wenckebach)

Answer 9

Impulse from the atria becomes harder and harder to propagate to ventricles.
Progressive prolongation of P wave
PR interval is longest right before dropped beat and shortest right after
QRS complex’s cluster into groups separated by non-conducted P waves

Question 10

First Degree AV block

Answer 10

Refractory period of the AV node is delayed
PR interval exceeds .20s
P waves can be buried in preceding T waves

Question 11

Ventricular Arrhythmia’s are:

Answer 11

Ventricular tachycardia
Ventricular flutter
Ventricular fibrillation

Question 12

Atrioventricular conduction defects are:

Answer 12

First degree (Mobitz I) AV block
Second degree (Mobitz II) AV block
Second degree (Wenckebach)
Third degree (complete heart block)

Question 13

Supraventricular Arrhythmias are:

Answer 13

When PAC's occur in succession 
Atrial fibrillation and flutter
AV nodal re-entry tachycardia
AV re-entry tachycardia
Atrial tachycardia

Question 14

Atrial fibrillation with Irregular RR response

Answer 14

Absence of discernible P waves
QRS normal
T wave obscured by f(fibrillatory) waves

Question 15

Atrial Fibrillation

Answer 15

Both atria beat chaotically not allowing ventricles to fill completely.
No P wave, Variable R-R interval
impulse reach ventricles in excess of 140-180 bpm
most common adult arrhythmia

Question 16

Atrial Flutter

Answer 16

Slower more organized rhythm than fibrillation
Atria contract faster than ventricles
f(flutter) waves appear
Usually associated with AV block

Question 17

Premature Atrial Contraction (PAC)

Answer 17

Originates in ectopic focus outside the SA node
Can come suddenly and then terminate, 3 or more in a row indicated SV tachycardia.
140-220 bpm
P wave may be premature and hidden in preceding T wave
P wave contours differ

Question 18

Hyperkalemia

Answer 18

Tall, peaked, narrow T waves in precordial leads

Question 19

Precordial leads

Answer 19

“chest leads”
provide a horizontal view of the heart
V1-V6

Question 20

Hypokalemia

Answer 20

Flattened T waves
appearance of U waves in anterior Precordial leads (V2, V3)
ST depression

Question 21

Hypercalcemia

Answer 21

Shortened QT interval

Question 22

Hypocalcemia

Answer 22

Prolonged QT interval

Question 23

Digoxin Toxicity

Answer 23

produces significant ECG changes
ST scooping depression
mild PR prolongation

Question 24

Left bundle branch block (LBBB)

Answer 24

failure to conduct an impulse through the left bundle branch.
lead V1 will have a deep S wave
large RR in V6 with duration of .12s

Question 25

Fascicular block

Answer 25

failure to conduct an impulse through the left anterior-superior fascicle, or the left posterior-inferior fascicle branches off of the Left bundle branch.

Question 26

Right bundle branch block (RBBB)

Answer 26

failure to conduct an impulse through the right bundle branch. RSR' pattern- secondary R wave in V1- QRS duration .12s Slurred S wave in V6

Question 27

Sinus tachycardia

Answer 27

rhythm exceeding 100 bpm

Question 28

Sinus arrhythmia

Answer 28

Exaggeration of the normal heart rate during respiration

Question 29

Sinus Bradycardia

Answer 29

less than 60 bpm

Question 30

Sinus rhythm

Answer 30

60-100 bpm | fairly regular and continuous

Question 31

Components of the cardiac conduction system

Answer 31

``` SA node AV node Bundle of His Left and right bundle branches Purkinje fibers ```

Question 32

P wave

Answer 32

First waveform in a cycle represents atrial depolarization .12 s

Question 33

PR interval

Answer 33

beginning of the P wave to the beginning of QRS complex | represents impulse transversing the AV node

Question 34

QRS complex

Answer 34

Ventricular depolarization

Question 35

ST segment

Answer 35

Low electrical activity following ventricular depolarization (sensitive indicator of ischemia during myocardial infarction) For end of QRS to beginning of T wave

Question 36

T wave

Answer 36

Ventricular repolarization

Question 37

QT Interval

Answer 37

From the beginning of the QRS to the end of the T wave ventricular depolarization and repolarization Shortens as heart rate quickens, lengthens as heart rate decreases indicator of predisposition to ventricular arrhythmias

Question 38

U wave

Answer 38

Deflection following T wave | origin uncertain

Question 39

Non- ST Segment Elevation Myocardial Infarction | NSTEMI

Answer 39

Does not penetrate entire width of the myocardium. ECG changes variable but include: - Downsloping ST segment depression of 1mm or more - T wave inversion - or both

Question 40

Right atrial enlargement (RAE)

Answer 40

Tall peaked P wave | associated with right ventricular hypertrophy

Question 41

Left atrial enlargement (LAE)

Answer 41

Biphasic P wave "double hump" | Longer duration of P wave in some leads

Question 42

Left ventricular hypertrophy (LVH)

Answer 42

Increase R wave height in ECG leads that reflect left ventricular potential