Cardio Management

Question 1

An electrocardiogram records an electrocardiograph. True/False?

Answer 1

False

Question 2

Charge differences during the cardiac cycle creates a dipole which generates an electrical field that is measurable with electrodes. The measured potential difference is greatest when the lead axis is perpendicular to the direction of the dipole. True/False?

Answer 2

False

Potential difference is greatest when lead axis is parallel to direction of the dipole

Question 3

Describe the standard limb leads, i.e. where they are aligned, what are the group of leads referred to as

Answer 3

Lead I: RA-LA
Lead II: RA-LL
Lead III: LA-LL
Einthoven’s triangle

Question 4

The positive electrode is the recording electrode. What does this mean?

Answer 4

The wave of depolarisation moves towards this electrode

Question 5

What does the P wave represent? How long is it?

Answer 5

Atrial depolarisation

0.08-0.10s

Question 6

What does the QRS complex represent? How long is it?

Answer 6

Ventricular depolarisation

Less than 0.10s

Question 7

What does the T wave represent?

Answer 7

Ventricular repolarisation

Question 8

What does the PR interval represent? How long is it?

Answer 8

AV nodal delay

0.12-0.20s

Question 9

What does the ST segment represent?

Answer 9

(maintained) Ventricular systole

Question 10

What does the TP interval represent?

Answer 10

Diastole

Question 11

What are the 3 augmented limb leads?

Answer 11

aVR, aVL and aVF

Question 12

Why is the aVR recording inverted on an ECG?

Answer 12

The wave of depolarisation is moving away from this electrode

Question 13

One large box (5 small squares) on an ECG represents how many seconds?

Answer 13

0.2 seconds (one small square = 0.04 seconds)

Question 14

How do we calculate heart rate on a regular ECG?

Answer 14

300/no. of large boxes between R-R peaks

Question 15

How do we calculate heart rate on an irregular ECG?

Answer 15

No. of QRS peaks in 30 large boxes x 10

Question 16

What are the main risk factors for CVD?

Answer 16

Hypertension
Smoking
Diabetes
Dyslipidaemia/obesity
Lack of physical activity

Question 17

Hypertriglyceridemia is associated with greater incidence of CVD events than hypercholesterolemia. True/False?

Answer 17

False

Question 18

HDL cholesterol tends to be low when triglycerides are high. True/False?

Answer 18

True

Question 19

Essential hypertension has a clear underlying cause. True/False?

Answer 19

False

Cause largely unknown; secondary hypertension usually has a cause

Question 20

What three points is an ECG isoelectric?

Answer 20

PR interval (atria depolarized)
ST (ventricles depolarized)
TP (all regions repolarized)

Question 21

Where are the 6 precordial leads placed on a torso?

Answer 21

V1: 4th IC space (RHS)
V2: 4th IC space (LHS)
V3: midway between V2 and V4
V4: 5th IC space, mid clavicular line
V5: some level as V4, mid axillary line
V6: some level as V4, mid axillary line

Question 22

What lead is an ECG best seen in and how long is it typically?

Answer 22

Lead 2

0.36-0.44 seconds

Question 23

What are the steps to interpreting an ECG?

Answer 23

1. Patient details - name, DOB
2. Date and time of ECG
3. Calibration of ECG paper
4. Determine axis
5. Workout rhythm using rhythm strip:
   - electrical activity?
   - regular/irregular rhythm?
   - HR?
   - P waves? Length of PR interval (3-5 small squares)?
   - Each P wave followed by QRS? QRS duration (2+ small squares)?
6. Individual leads for voltage changes

Question 24

What is a classical sign of NSTEMI/Unstable angina on an ECG? How are these then differentiated?

Answer 24

ST depression

Troponin raised in NSTEMI

Question 25

What is used in determining deviation of the heart axis?

Answer 25

Lead 1 and AvF

Question 26

What is the requirement for ST elevation on an ECG?

Answer 26

> 1mm in two adjacent limb leads

>2mm in precordial leads

Question 27

What does AF look like on an ECG?

Answer 27

Little atrial contraction (absent P waves)
QRS normal (problem above AVN)