Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Cardio > EKG > Flashcards

EKG Flashcards

1
Q

What is the P wave?

A

depolarization of the atria (first deflection on EKG)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the QRS?

A

depolarization of the ventricular muscles (therefore also repolarization of atria); Q: typically downward before upward reflection; R: upward deflection; S: downward

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the T wave?

A

Repolarizaiton of the ventricles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How does conduction travel?

A

sinus beat starts in the SA node; depolarization spreads through the atria and reaches the AV node; epolarization continues to the bundle of His and bundle branches, Purkinje fibers, and ventricular myocardium; activation in the ventricles starts out on the left side of the
IV septum and travels to the R

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How many electrodes are used in EKG and where are they placed?

A

right arm, left arm, right leg (not used - grounds), left leg, V1-V6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Where are V1-V6 placed?

A 
V1: 4th ICS, 2 cm to the right of sternum;
V2: 4th ICS, 2cm to the left of sternum;
V3 Midway between V2 and V4;
V4 5th ICS, left midclavicular line;
V5 5th ICS, left anterior axillary line;
V6 5th ICS, left midaxillary line;
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the direction of the different leads?

A

I: right arm to left arm; II: right arm to left leg; III: left arm to left leg; aVF: middle of body to left leg (down); aVL: middle of body to left arm; aVR: middle of body to right arm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

In which directions should the EKG go?

A

If going towards a +, then up! If going away from a +, then down; if going towards a + and then past or away, then going up then down

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the 8 most important things to look at in an EKG?

A
  1. Calibration;
  2. Heart Rate;
  3. Heart Rhythm;
  4. Intervals (PR, QRS,QT);
  5. Mean QRS Axis;
  6. Abnormalities of the P-wave;
  7. Abnormalities of the QRS (hypertrophy, bundle branch block, infarction);
  8. Abnormalities of the ST-segment/T-wave
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is important about calibration?

A

Standard calibration has a reference pulse of 1 mV (10 mm high) and a large box that represents 0.2 sec (200 ms)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How can you calculate heart rate from an EKG?

A
  1. 1,500/(# mm between beats) = HR;
  2. Count-off the # of large boxes between two QRS complexes: 300 – 150 – 100 – 75 – 60 – 50;
    3.(Especially) for irregular rhythms such as atrial fibrillation:
    Count the # of complexes during 6 sec of the recording and x by 10. ECGs often have time markers spaced 3 sec apart. If 3-second markers are not present, count out 15 big boxes: 15 boxes x 200 msec/box=3000 msec
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the characteristics required for sinus heart rhythm?

A

1) Every P wave is followed by a QRS, &
2) Every QRS is preceded by a P wave, &
3) P-wave is upright in leads I, II, and III, &
4) The PR interval is greater than 0.12 sec (3 small boxes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is sinus bradycardia?

A

HR below 60 bpm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is sinus tachycardia?

A

HR above 100 bpm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the corrected QT?

A

divide the measured QT/ square root of the R-R interval (in seconds); this is b/c QT interval should decrease as HR goes up

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is a normal PR?

A

120-200 msec (3-5 small boxes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What does increased PR mean?

A

First-degree AV block

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What does decreased PR mean?

A

Preexcitation/WPW, Junctional rhythm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is normal QRS?

A

less than 100 msec (less than or equal to 2.5 small boxes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What does increased QRS mean?

A

Bundle branch block, Ventricular ectopy, Drug effect (e.g., certain antiarrhythmic drugs), increased potassium

21
Q

What is the normal range for QT corrected?

A

equal to or greater than 450m/460f msec

22
Q

What does decreased QT corrected mean?

A

Short QT syndrome, elevated calcium

23
Q

What does increased QT corrected mean?

A

decrease in K or Ca, Ischemia, Congenital, toxic drug effect (e.g., certain antiarrhythmic drugs); this is “long QT”

24
Q

What is 1st degree AV block?

A

PR interval is more than 5 small boxes
block slowing conduction down

25
Q

What is 2nd Degree AV block Type I?

A

AV node struggling to keep up - PR int
getting progressively longer until it gives
up/cycles

26
Q

What is 2nd Degree AV block Type II?

A

all or nothing - either works correctly or
doesn’t work at all

27
Q

What is 3rd Degree AV block?

A

more P waves than QRS complexes
complete block b/w atria and ventricles
(complete heart block)

28
Q

What does long QT look like on an EKG?

A

Q to T interval longer than half of the overall interval

29
Q

What is the mean QRS axis?

A

Represents the vector of QRS depolarization; Normal: -30° to +90°; More negative than -30° represents left axis deviation; More positive than +90° represents right axis deviation.

30
Q

How can you determine QRS axis?

A

Look in leads I & II! - If both +, normal axis. -If I+/II-, leftward axis -If I-/II+, rightward axis

31
Q

What does leftward axis deviation mean clinically?

A
  • Left Ventricular Hypertrophy
  • Left Anterior Fascicular Block
  • Inferior MI
32
Q

What does rightward axis deviation mean clinically?

A
  • Right Ventricular Hypertrophy
  • Left Posterior Fascicular Block
  • Pulmonary embolus
33
Q

How do you determine abnormalities in the P waves?

A

Look in leads II and V1; enlargement in II (more than 2.5 small boxes) high means problem with R and wide means problem with L; enlargement in V1 is greater than 1 box for either curve

34
Q

How does left ventricular hypertrophy present on EKG?

A

larger-than-normal electrical forces are generated by the LV; Leads on the left side of the heart (i.e., V5, V6, I, aVL) have taller-than-normal R waves +/- T-inversions; Leads on the right side of the heart (i.e., V1 & V2) have the opposite: deeper-than-normal S wave

35
Q

What is a bundle branch block?

A

May develop from ischemic or degenerative damage. Slow myocyte-to-myocyte spread of electrical activity. The delay prolongs depolarization/widens the QRS.

36
Q

What does a QRS duration of 0.10-0.12 s (2.5-3 small boxes) mean?

A

incomplete bundle branch block

37
Q

What does QRS duration of more than 0.12 s (more than 3 small boxes) mean?

A

complete bundle branch block

38
Q

What is right branch block and how does it present on EKG?

A

Think right heart strain (e.g., pulmonary embolism, rate-related aberration); activation is normal, switches to L ventricle, but bundle branch finally lets electrical activity
come through it after L ventricle does what it needs to do - R ventricle slowly depolarizes; RSR in V1 - S in V6 - Can interpret Q-wave changes!

39
Q

What is left branch block and how does it present on EKG?

A

Think degenerative disease, cardiomyopathy, myocardial infarction; starts off strange - activation heads down R side of septum (activates toward the L side); then the R ventricle does depolarize some, then headed toward L ventricle again; - S in V1 - Broad R in V6 - Cannot interpret Q-waves or ST-T changes!

40
Q

What are pathological Q waves?

A

Pathological if width is more than 1 small box wide & depth is more than 25% of the total QRS height. Represents absence of electrical forces from infarcted cells. If a Q wave appears in only a single ECG lead, it is not diagnostic of an infarction- need at least 2 consecutive leads.

41
Q

What does abnormal Q wave in the II, II, aVf mean?

A

inferior MI caused by RCA

42
Q

What does abnormal Q wave in the V1-V2 mean?

A

anteroseptal MI caused by LAD

43
Q

What does abnormal Q wave in V3-V4 mean?

A

anteroapical MI caused by LAD (distal)

44
Q

What does abnormal Q wave in V5-V6, I, aVL mean?

A

anterolateral MI caused by CFX

45
Q

What does tall R wave in V1-V2 mean?

A

posterior MI caused by RCA

46
Q

What does ST elevation indicate?

A

Myocardial infarction; this is because injured segment is partly depolarized away from electrode before rest of heart normally depolarizes, which causes downward shift in recording electrode; ECG is thinking that the baseline is @ usual point (manifests as ST elevation)

47
Q

What are common causes of ST elevation?

A

Myocardial infarction, pericarditis, coronary vasospasm; could also be cerebrovascular accident, pulmonary embolism, hypothermia

48
Q

What are some T wave abnormalities?

A 
Long QT: Hypocalcemia, Genetic, Drugs
Short QT: Hypercalcemia, hyperkalemia
Inverted T-waves: ischemia, LVH, digoxin
Peaked T-waves: Hyperkalemia
Flat T-wave & U-waves: Hypo K+, Mg++

Cardio (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions