ECG Wave Forms

Question 1

An inverted P wave/ biphasic P wave may indicate ?

Answer 1

An ectopic rhythm or ischemia.

Question 2

An unusually tall P wave may be a sign of what ?

Answer 2

Atrial enlargement

Question 3

An unusually wide QRS Complex >120 Ms maybe a sign of ?

Answer 3

BBB or ventricular hypertrophy

Question 4

Depression of the PR segment is seen in ?

Answer 4

Pericarditis

Question 5

PR interval = ?

Answer 5

P wave + PR segment

Question 6

QRS interval=

Answer 6

The duration of the QRS Complex

Question 7

The duration of the normal QRS Complex?

Answer 7

80 to 100 Ms. When it is between 100 to 120ms, the QRS duration is slightly prolonged.

Question 8

A QRS duration> 120 Ms indicates?

Answer 8

The cardiac impulse conducts through cardiac myocytes instead of Hiss- Purkinje system. It often occurs in BBB, non specific interventricular conduction delays and ventricular arrhythmias.

Question 9

QT interval=

Answer 9

The duration of QRS Complex+ ST segment+ T wave

Question 10

What is RR interval

Answer 10

It is the duration of all wave forms and segments in one cardiac cycle

Question 11

What is the duration of normal PR interval?

Answer 11

120-200 Ms.

Question 12

A PR interval < 120 Ms indicates?

Answer 12

An abnormal conduction between atria and ventricles

Question 13

A PR interval>200 Ms indicates?

Answer 13

Delayed conduction through the AV node due to age related degeneration of the AV node or medications such a calcium channel blockers or beta blockers.

Question 14

One small square of ECG =

Answer 14

40 Ms or 0.04 sec

Question 15

One large square of ECG is equal to?

Answer 15

200 Ms or 0.20 seconds. / 5mm

Question 16

An ECG rhythm strip recorded for 1 min will have how many large and small squares?

Answer 16

1500 small squares or 300 large squares

Question 17

The large square method of ECG rate calculation (300/RR intervals in large square) is useful in ?

Answer 17

Regular rhythms at regular rates.

Question 18

Small square method of ECG rate calculation is useful in ( 1500/RR interval in small squares)?

Answer 18

Useful for very fast regular rhythms.

Question 19

R wave method of ECG rate calculation is useful in ( number of R waves X6)?

Answer 19

Useful for slow and irregular rhythms.

Question 20

Normal HR in newborn?

Answer 20

110-150 beats

Question 21

Normal HR in 2 years old?

Answer 21

85-125 bpm

Question 22

Normal HR in 4 years old?

Answer 22

75-115BPM

Question 23

Normal HR in 6 years old+ ?

Answer 23

60 to 100 BPM

Question 24

What is the advantage of doubling the standard rate of ECG paper speed?

Answer 24

It can help to reveal subtle ECG findings hidden at the slower rates, in particular atrial flutter waves in a 2:1 block.

Question 25

what are the 7 steps of ECG rhythm analysis?

Answer 25

1) Rate - Tachycardia or Bradycardia 2) pattern of QRS Complex - Regular or irregular. If irregular is it regularly irregular or irregularly irregular? 3) QRS morphology- Narrow vs wide 4) P wave - absent or present 5) Relationship between P wave and QRS Complex - AV association or dissociation 6) Onset and termination- abrupt or gradual 7) Response to vagal maneuvers.

Question 26

What direction of current lead V1 and V2 measure?

Answer 26

Anterior forces as positive waves and posterior forces as negative waves.

Question 27

Lead 1 and V6 measure what direction of force ?

Answer 27

Leftward forces

Question 28

Normal P wave axis ?

Answer 28

0- 75 degree

Question 29

What is the normal P wave duration?

Answer 29

<120 ms

Question 30

What are the inferior leads ?

Answer 30

Lead 2, aVF, and 3 are called inferior leads because they observe the inferior wall of the left ventricle.

Question 31

Lateral leads of ECG are ?

Answer 31

Lead 1, aVL, V5, and V6

Question 32

Anterior leads of ECG are

Answer 32

V3 and V4

Question 33

Septal leads of ECG are ?

Answer 33

V1 and V2

Question 34

Einthoven's Law ?

Answer 34

Lead 1 + Lead 3 = lead 2

Question 35

ECG leads of septal wall supplied by LAD?

Answer 35

V1 and V2

Question 36

ECG leads of anterolateral wall supplied by LAD?

Answer 36

V5 and V6

Question 37

ECG leads of anterolateral wall supplied by LCX ?

Answer 37

V4 and V5

Question 38

ECG leads of anterior wall supplied by LAD?

Answer 38

V3 and V4

Question 39

ECG leads of lateral wall supplied by LCX?

Answer 39

Lead 1, aVL, -aVR

Question 40

ECG leads of inferior wall supplied by RCA?

Answer 40

Lead 2,3,aVF

Question 41

Duration of QT interval?

Answer 41

400 to 440 Ms in men and 400 to 460 Ms in women