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ESA 2- Cardiovascular System > ECG > Flashcards

Flashcards in ECG Deck (14)
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Describe the placement of limb leads

Red: right arm
Yellow: left arm
Green: left foot
Black: right foot


Describe the different views provided by limb leads

LI (RA - LA): 0 d
LII (RA - LF): 60 d
LIII (LA - LF): 120 d

aVF: 90 d
aVL: -30 d
aVR: -150 d


Describe the placement of chest leads

V1 (red): 4th IC space, R sternal edge
V2 (yellow): 4th IC space, L sternal edge
V3 (green): between V2 and V4
V4 (brown): 5th IC space, mid-clavicular line
V5 (black): between V4 and V6
V6 (purple): 5th IC space, mid-axillary line


Which leads show anterior heart

V3, V4


Which leads show inferior heart



Which leads show septum

V1, V2


Which leads show lateral heart

LI, aVL, V5, V6


ECG wave upstroke shows...

Depolarisation towards or repolarisation away from positive electrode


ECG wave downstroke shows...

Depolarisation away from or repolarisation towards positive electrode


What does each segment of the ECG wave show

P wave: atrial depolarisation
PR segment: AVN 120ms delay and bundle of His depolarisation
Q: septum depolarisation (from L to R)
R: ventricular depolarisation (from endo to epicardium)
S: ventricular base depolarisation (towards atria)
ST segment: delay to ensure complete depolarisation
T wave: ventricular repolarisation (epi to endocardium)


how may small and large squares make 1 sec

5 large squares
25 small squares


1 large square and 1 small square = how many seconds

1 large square = 0.2 secs
1 small square = 0.04 sec


how is HR calculated if it is regular? irregular?

Regular: no. of large squares in R - R interval, divided by 300

Irregular: no. of QRS in 30 sqrs (i.e. 6 secs) x 10


how is presence of sinus rhythm determined

1. is rhythm regularly regular?
2. what is HR?
3. are P waves present and are they upright in leads I and II?
4. is PR interval normal (3-5 small sqrs)?
5. is every P wave followed by QRS and every QRS followed by P wave?
6. is QRS normal width (<3 small sqrs)?