3. Normal ECG 1/2

Question 1

What occurs during QRS and what are the normal times?

Answer 1

Ventricular depolarization… Normal less than .12s, greater than .12s = bundle branch block/hypertrophy

Question 2

5 small squares is equal to 5mm/0.2s. One small square is equal to?

Answer 2

1mm and 0.04s

Question 3

What occurs during P wave and which leads can be found upright and inverted?

Answer 3

P wave during atrial depolarization

urpright in 1,2,V4-V6, AVF

Invert: AVR (variable in rest)

Question 4

What occurs during PR interval and what is the normal time?

Answer 4

Beginning of P wave to beginning of QRS complex: ***time from SA node to ventricular muscle fiber
Normal time is 0.12-0.2seconds (3-5squares)

Question 5

What occurs during QRS complex, what is their duration and common width?

Answer 5

Ventricular depolarization usually 0.05-0.10s in duration. Q waves usually not wider than 0.04s or 1 full square

Question 6

In Q waves which are narrow and small, 1-2 mm is normal in? (5)

Answer 6

1, AVL, AVF, V5, V6

Question 7

ST segment is after QRS complex and is normally isoelectric (relative to baseline), what is normal in standard and chest leads?

Answer 7

In standard leads (1,2,3 AVF/R/L) elevated no more than 1mm and 2mm in chest leads, usually are not depressed more than 1/2 mm

Question 8

What does a depressed or elevated ST segment indicate?

Answer 8

Depressed: subendocardial
Elevated: subepicardial or transmural injury/ichemia

Question 9

What occurs during T wave, what are the upright and inverted heights found in, what are the normal heights in mm and what is the normal shape?

Answer 9

Ventricular repolarization
Upright: 1,2,V3-V6
Inverted AVR
Shape: round and assymetrical
Height: not greated than 5mm in standard or 10mm in chest (precordial) leads

Question 10

QT duration is length of ventricular systole. If abnormal length can signal?

Answer 10

Myocardial ischemia/injury/infarction

Question 11

When ST is elevated= injury, when T wave is inverted = ?

Answer 11

ischemic pattern

Question 12

Q wave or QS complex abonormalities signal?

Answer 12

pattern of necrosis or infarction

Question 13

When is an ECG considered a sinus rhthym?

Answer 13

When there is a P wave before the QRS

Question 14

If someone exercises alot and is healthy, what can be expected of their T waves?

Answer 14

T waves can be taller and still be normal

Question 15

When the P wave looks like an M, it is called P-mitrale. P pulmonale: flat in lead 1, pointed/tall in Lead 2/3. What is characteristic of AV junctional rhythm?

Answer 15

Inverted P wave in Leads 2 and 3 with short PR interval

Question 16

A prolonged PR interval can indicate a AV block due to coronary disease. A shortened PR interval can be due to?

Answer 16

AV junctional
Wolff Parkinson White syndrome
Lown Ganong-Levine syndrome

Question 17

Where can you find an elevated fire mans hat on an ECG and what would that signal?

Answer 17

elevated from baseline Firemans hat in the ST segment due to myocardial infarction or injury

Question 18

What are artifacts on an ECG reading?

Answer 18

Artifacts are square/rectangular readings on ECG which signal that the machine/leads are not hooked up correctly

Question 19

What are the numbers for estimating HR? What occurs if its past the lowest number?

Answer 19

One box from where you are measuring is 300, then 150, 100, 75, 60
Anything past 60 is bradycardia
OR 300/(how many boxes from point)

Question 20

What is the rhythm where a P wave precedes QRS?

Answer 20

SINUS rhythm

Question 21

What two abnormalities present as P wave following QRS?

Answer 21

1. SVT (AV nodal re-entry tachycardia)

2. Junctional rhythm

Question 22

Atrial fibrillation, atrial flutter, juntional/ventricular escape rhythms, junctional tachycardia and ventricular tachycardia all have absent?

Answer 22

P waves

Question 23

Which 6 leads meet to form six interseting leads in a frontal plane on the chest?

Answer 23

L1,2,3 AVF,R,L

Question 24

A normal axis is?

Answer 24

Positive deflection in Lead1 and AVF

Question 25

A left axis is ?

Answer 25

Positive deflection in Lead 1 and negative in AVF

Question 26

A right axis is?

Answer 26

A negative deflection in lead 1 and positive in AVF

Question 27

A extreme right axis is?

Answer 27

a negative deflection in both lead 1 and AVF