EKG 3

Question 1

Ruler method

Answer 1

. Way to determine HR
. Line up starting point of rate ruler w/ some event (largest deflection of QRS)
. Line up subsequent same event w/ scale on ruler (for 1 beat ruler) or line up 3rd same event w/ scale for 3 beat ruler
. Doesn’t work well on photocopies

Question 2

Grid method

Answer 2

. Way to measure HR
. Look for waves w/ heavy vertical lines
. Read values from a table
. 300/number of large boxes = heart rate

Question 3

Scan methods

Answer 3

. Operate on principle of determining number of cycles occurring in given period of time
. Longer the time period, the more cycle and more accurate rate determination
. Important for when rate is irregular
. Can determine from 6 sec strips
. Rate in bpm = beats per 6 sec x 10

Question 4

Tachycardia

Answer 4

Over 100 bpm

Question 5

Bradycardia

Answer 5

Under 60 bpm

Question 6

What to look for in examining he waves

Answer 6

. Shape
. Duration
. Max amplitude
. Estimate direction of mean vector

Question 7

P wave shape, duration, amplitude , and direction

Answer 7

. Smooth, not peaked, notched, or double except V1 where it may be biphasic to distinguish R and L side activity
. Duration: 0.08-0.1 sec
. Max amplitude 2.5 mm (0.25 mV)
. direction: upright in lead II otherwise abnormal

Question 8

Reason P waves may be noticed or double?

Answer 8

. Hypertrophy or enlargement

. Delayed conduction btw L and R atria

Question 9

Reason for slower P wave duration

Answer 9

. Slowed conduction through atria

Question 10

Reason for P wave amplitude over 2.5 mm

Answer 10

. W/o notching it is indicative of RA hypertrophy or enlargement due to pulmonary disease

Question 11

QRS shape, duration, amplitude, and direction

Answer 11

. Needs a notch (does not extend to baseline)
. Duration: no longer than 0.1 sec (only lead 1 reveals correct duration, other leads may cut off portions of depolarization making it shorter than it really is)
. Max amplitude in lead II btw 5 mm and 30 mm
. Direction: R wave progression from leads V1-6 is normal, transition from mostly neg. QRS to pos. QRS occurs at lead V3 or 4

Question 12

Reason for longer QRS duration over 0.1 sec

Answer 12

. Slowed conduction through normal pathway
. Conduction through abnormal pathway
. Often assoc. w/ notch, bump, or rounded deflection

Question 13

Loss of normal R wave progression is indicative of ____

Answer 13

. Loss of myocardium after MI

. Hypertrophy of one side or the other

Question 14

T wave shape, duration, amplitude, and direction

Answer 14

. Slightly rounded and slightly asymmetrical
. Duration not measured and considered variable
. Max amplitude in lead II less than 5 mm
. Direction similar as mean QRS vector for that heart

Question 15

Abnormal T wave shapes

Answer 15

. Peaked
. Biphasic
. Notched

Question 16

Large peaked T waves fond in what conditions?

Answer 16

. Hyperkalemia

Question 17

Flattened or inverted T waves indicative of ___

Answer 17

. Hypokalemia

Question 18

Abnormal S-T segment

Answer 18

. Elevated or depressed from isoelectric point more than 1 mm at 0.08 sec after J point

Question 19

Exercise stress test reason

Answer 19

. Shows evidence of S-T depression indicative of myocardial ischemia that is not apparent at rest

Question 20

STEMI

Answer 20

. S-T segment elevation MI
. Dangerous type of heart attack
. Sign of blocked major coronary artery