Exam 2: EKG

Question 1

What is the total number of leads in a 12 Lead EKG?

Answer 1

10 leads: 4 Limb and 6 Chest leads

Question 2

Which leads represent the right ventricle?

Answer 2

V1, V2

Question 3

Which leads represent the left side of the heart?

Answer 3

V5, V6, Lead I, aVL

Question 4

What does the P-wave represent?

Answer 4

Atrial contraction

Question 5

What does the PR interval represent?

Answer 5

Time taken for excitation to spread from the SA node across the atrium to the ventricular muscle

Question 6

What does the QRS complex represent?

Answer 6

Ventricular contraction

Question 7

What does the ST segment represent?

Answer 7

Ventricular relaxation

Question 8

What does the T-wave represent?

Answer 8

Ventricular repolarization

Question 9

What patient details are important when reading an ECG?

Answer 9

Patient’s name, date of birth, hospital number, and location

Question 10

What situation details should be noted when reading an ECG?

Answer 10

Time of ECG, number of ECG in series, presence of chest pain, relevant clinical details

Question 11

How can the rate on an ECG be calculated?

Answer 11

• Count QRSs on one line and multiply by six
• Count large squares between R waves and divide 300 by this number

Question 12

What is the method to assess rhythm on an ECG?

Answer 12

Check if the rhythm is regular or irregular using the ‘paper test’

Question 13

What does axis represent in an ECG?

Answer 13

Sum of all electrical activity in the heart

Question 14

What indicates a normal axis in leads I and aVF?

Answer 14

Both have positive net deflections

Question 15

What causes left axis deviation?

Answer 15

• Left ventricular hypertrophy (LVH)
• Left anterior hemiblock
• Inferior myocardial infarction
• Hyperkalemia
• Ventricular tachycardia (VT)
• Paced rhythm

Question 16

What causes right axis deviation?

Answer 16

• Right ventricular hypertrophy (RVH)
• Pulmonary embolism (PE)
• Anterolateral myocardial infarction
• Left posterior hemiblock

Question 17

What can indicate complete heart block in P-waves?

Answer 17

P-waves not associated with QRS complexes

Question 18

What is ‘p mitral’ indicative of?

Answer 18

Left atrial hypertrophy

Question 19

What can cause a prolonged PR interval?

Answer 19

First degree heart block

Question 20

What is a q-wave?

Answer 20

An initial downward deflection in the QRS complex

Question 21

What is the normal width of a QRS complex?

Answer 21

< 0.12 secs (3 small squares)

Question 22

What can cause a wide QRS complex?

Answer 22

• Bundle branch blocks (LBBB or RBBB)
• Hyperkalemia
• Paced rhythm
• Ventricular pre-excitation
• Ventricular rhythm
• TCA poisoning

Question 23

What indicates ST segment elevation?

Answer 23

Infarction

Question 24

What indicates ST segment depression?

Answer 24

Ischemia

Question 25

What is high-takeoff in relation to ST elevation?

Answer 25

Benign early repolarization with widespread concave ST elevation

Question 26

What does the QT interval measure?

Answer 26

Time between the start of the q-wave and the end of the t-wave

Question 27

What are some causes of long QT?

Answer 27

• Drugs (e.g., TCAs, erythromycin)
• Metabolic issues (e.g., hypokalemia)
• Familial conditions
• Other (e.g., myocarditis)

Question 28

What changes can hyperkalemia cause in T-waves?

Answer 28

Peaked T waves

Question 29

What is a classic presentation of hyperkalemia on an ECG?

Answer 29

• Small p-wave
• Tall, tented (peaked) t-wave
• Wide QRS

Question 30

What is a common normal variant for T-wave inversion?

Answer 30

Commonly inverted in aVR and V1

Question 31

What is indicated by tall R waves in V6 plus the depth of S waves in V1 greater than 35mm?

Answer 31

Left ventricular hypertrophy (LVH)