CVS OSCE - ECGs

Question 1

First Steps (reading)

Answer 1

CONFIRM NAME AND DOB

DATE AND TIME ECG PERFORMED

CHECK CALIBRATION = 25mm/s and 10mm/1mV

Question 2

Heart Rate Ranges (reading)

Answer 2

Normal: 60-100 bpm
Tachycardia: > 100 bpm
Bradycardia: < 60 bpm

Question 3

What is the PR interval?

Answer 3

time for atrial depol. to ventricular depol.

Question 4

What is the ST segment?

Answer 4

end of ventric. depol and beginning of ventric repol.

Question 5

What is the QRS complex?

Answer 5

Ventricular depolarization

Question 6

What is the QT interval

Answer 6

time spent in. ventricular depol and repol.

Question 7

SYSTEMIC APPROACH TO ECG ACRONYM

Answer 7

A ctivity
R ate
I rregular/regular

B roaad/narrow QRS
A trial activity - P waves?
R elationship of P to QRS

Question 8

Calculating Rate of QRS

Answer 8

1. 300/squares between QRS = 300,150, 75, 60, 50 BPM
2. for irregular rates,
   - COUNT UP TO 30 LARGE SQUARES = 6SECS
   - THEREFORE (nQRS)x10 = BPM

Question 9

Irregular/Regular of ECG

Answer 9

Mark 3 QRS complexes, and see if the other QRS line up on the next 3

Question 10

Broad/narrow QRS

Answer 10

Is the QRS interval less than 3 little squares? (0.12 seconds) therefore the impulse was inititated at or above the AV node

Broad complexes = complex arises from ventricles thus abnormal depol in ventricles

Question 11

Atrial activity - P waves and relationship to QRS?

Answer 11

does a QRS always follow a P wave?

PR interval = 3 to 5 small squares = sinus rhythm

Question 12

1st degree heart block

Answer 12

QRS related to P but PR is elongated thus

impulse still reaches the ventricles, but moves more slowly than normal through the AV node

Question 13

2nd degree heart block

Answer 13

QRS and P relationship present but variable

TYPE 1 / Mobitz 1 / Wenckebach’s AV block

• slower and slower until QRS is skipped, PR interval longest before drop
• PP interval constant

TYPE 2
Signals reach ventricles but irregular skip (variable), constant PR, and P constant

Question 14

3rd degree heart block

Answer 14

complete AV dissociation and severe bradycardia

Question 15

Placing ECGs

Answer 15

*remove metallic objects, watches, phones,
* lie down 45º
* expose chest, and lower legs and wrists
* ?PAIN, confirm Id and DOB
* expiry of sticker packs
V1 @ 4thIC at RIGHT STERNAL EDGE
V2 @ 4thIC at LEFT STERNAL EDGE

V4 @ 5thIC midclavic

V6 @ md-axillary lin horizonttal from V4

LIMB LEADS
R (right arm)
Y (left arm)
G (Left leg)
B (right leg)