Basic EKG

Question 1

How many leads are included in a 12 lead EKG?

Answer 1

10 leads: 4 Limb and 6 Chest leads

Question 2

What does the V1, V2 leads represent on an ECG?

Answer 2

Right ventricle (RV)

Question 3

What does the V3, V4 leads represent on an ECG?

Answer 3

Septum

Question 4

What does the V5, V6 leads represent on an ECG?

Answer 4

Left side of the heart

Question 5

What does the PR interval represent?

Answer 5

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

Question 6

What does the QRS complex indicate?

Answer 6

Ventricular contraction

Question 7

What is indicated by the ST segment?

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 interpreting an ECG?

Answer 10

Time of ECG, number of ECG in series, presence of chest pain

Question 11

How can the rate on an ECG be calculated?

Answer 11

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

Question 12

What are the characteristics to assess in an ECG rhythm?

Answer 12

Regularity, irregularity, and whether it is regularly or irregularly irregular

Question 13

What defines the axis in an ECG?

Answer 13

The sum of all the electrical activity in the heart

Question 14

What is the normal axis orientation in an ECG?

Answer 14

Normal axis lies to the left

Question 15

What indicates right axis deviation in an ECG?

Answer 15

Lead I has a net negative deflection while aVF is positive

Question 16

What can cause left axis deviation?

Answer 16

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

Question 17

What can cause right axis deviation?

Answer 17

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

Question 18

What is a characteristic of p-waves in atrial fibrillation?

Answer 18

P-waves may not be visible

Question 19

What does a notched p-wave indicate?

Answer 19

Left atrial hypertrophy, often caused by mitral stenosis

Question 20

What is the normal duration of the QRS complex?

Answer 20

< 0.12 seconds

Question 21

What causes a wide QRS complex?

Answer 21

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

Question 22

What indicates ST segment elevation?

Answer 22

Infarction

Question 23

What indicates ST segment depression?

Answer 23

Ischemia

Question 24

What is high-takeoff in an ECG?

Answer 24

Benign early repolarization characterized by widespread concave ST elevation

Question 25

What is the QT interval?

Answer 25

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

Question 26

What can cause a long QT interval?

Answer 26

* Drugs * Metabolic issues * Familial conditions * Other health issues

Question 27

What are classic changes in hyperkalemia?

Answer 27

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

Question 28

What can cause flattened or inverted T-waves?

Answer 28

* Normal variant * Ischemia * Ventricular hypertrophy * LBBB * Digoxin * Hypokalemia

Question 29

What is the significance of a tall QRS complex?

Answer 29

Suggestive of left ventricular hypertrophy (LVH)

Question 30

What is the criteria for LVH on an ECG?

Answer 30

Height of R wave in V6 + depth of S wave in V1 > 35mm

Question 31

What indicates a complete heart block?

Answer 31

P-waves not associated with QRS complexes