Brainscape's Knowledge GenomeTM

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


See full index

Cardiovascular > 14. Clinical IV - Conducting System and the ECG > Flashcards

14. Clinical IV - Conducting System and the ECG Flashcards

1
Q

PHASES in CARDIAC MYOCYTE (NON-PACEMAKER) ACTION POTENTIAL

A

4 - FLAT, STABLE RESTING POTENTIAL at -90 mv

0 - DEPOLARISATION due to Na+ INFLUX

1 - INITIAL REPOLARISATION as K+ channels open

2 - PLATEAU as Ca2+ channels open

3 - Rapid REPOLARISATION due to K+ efflux (ca2+ channels close)

4 - resting potential - K+ efflux

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

in ECG what does QT INTERVAL represent

A

LENGTH of VENTRICULAR DEPOLARISATION & REPOLARISATION

  • relates to HEART RATE
    slower heart rate -> longer QT interval
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

PHASE 0 - rapid DEPOLARISATION due to Na+ INFLUX, of CARDIAC MYOCYTES ACTION POTENTIALS is represented by which part on an ECG

A

QR INTERVAL

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

RS INTERVAL (down slope) on ECG represents which PHASE of the CARDIAC MYOCYTE ACTION POTENTIAL

A

INITIAL REPOLARISATION

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

PHASE 2 PLATEAU is represented by which part on ECG

A

ST INTERPHASE

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

T WAVE REPRESENTS which PHASE of CARDIAC MYOCYTE ACTION POTENTIAL

A

PHASE 3 REPOLARISATION (K+ efflux)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

PR SEGMENT on ECG represents…

A

DELAY at AV NODE

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

what does ABSOLUTE REFRACTORY PERIOD mean

A

CANNOT GENERATE NEW ACTION POTENTIAL in this period

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

RELATIVE REFRACTORY PERIOD is when a stronger than before stimulus may generate a new action potential. what part of the ECG does it COINCIDE with

(stimulation here may cause life threatening arrhythmias)

A

T WAVE APEX

  • during REPOLARISATION
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

CONDUCTION starts where (via PURKINJE FIBRES) and goes in what DIRECTION of heart layers

A

in ENDOCARDIUM

and spreads outwards TOWARDS EPICARDIUM

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

12 LEAD ECG uses how many ELECTRODES

(all 12 leads are Bipolar)

A

10 ELECTRODES

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

in an ECG RECORDING a 1 MM SQUARE corresponds to how much VOLTAGE and how much TIME if the PAPER SPEED is 50 mm/s

A

0.1 mV

0.02 seconds

(large 5 mm square is 0.5 mV and 0.1 seconds)

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

what are the 2 ANATOMICAL PLANES used for ECG LEADS

A

FRONTAL PLANE & HORIZONTAL PLANE

detecting electrical vectors travelling in frontal / horizontal plane

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

CHEST LEADS are placed in which PLANE

A

HORIZONTAL PLANE

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

what are the 2 ELECTRODES used in an ECG

A

EXPLORING ELECTRODE : + POSITIVE deflection/wave (upwards above baseline)
the electrical vector is directed TOWARDS it

REFERENCE ELECTRODE: - NEGATIVE deflection (downwards below baseline)
electrical vector is directed AWAY from Exploring Electrode

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

which ELECTRODE produces a POSITIVE WAVE

A

EXPLORING as the electrical vector is directed TOWARDS it

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

AVF LEAD is at what ANGLE of ELECTRICAL AXIS

A

90 DEGREES

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q
  • AVR LEAD is at what ANGLE of ELECTRICAL AXIS

(recommended that avR lead is inverted to -avR as this fills a gap in the coordinate system and thus facilitates interpretation of the ECG)

A

30 DEGREES

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

AVL LEAD is at what ANGLE of ELECTICAL AXIS

A

-30 DEGREES

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

there are 6 ELECTRODES and 6 LEADS across the CHEST WALL (horizontal plane).

what do V1 and V2 OBSERVE

A

VENTRICULAR SEPTUM (SEPTAL LEADS) normally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what do V3 and V4 across the chest wall observe

A

ANTERIOR WALL of LEFT VENTRICLE

(ANTERIOR LEADS)

22
Q

what do V5 and V6 across the chest wall observe

A

LATERAL WALL of LEFT VENTRICLE

(LATERAL LEADS)

23
Q

in ECG if the 1ST WAVE is NEGATIVE (below baseline) what wave is it

A

Q WAVE

24
Q

what does it mean in an ECG if the 1ST WAVE is POSITIVE (above baseline)

A

NO Q WAVE

25
Q

all POSITIVE WAVES in an ECG are which wave

A

R WAVE

26
Q

any NEGATIVE WAVE AFTER a POSITIVE (R) WAVE is what wave

A

S WAVE

27
Q

How do we represent LARGE and SMALL WAVES in ECG

A

LARGE - CAPITAL LETTERS

SMALL - lower case

28
Q

in ECG what is the 1ST DEPOLARISATION

A

the ATRIA

29
Q

in ECG what is the 2ND DEPOLARISATION of

A

INTERVENTRICULAR SEPTUM (via purkinje fibres)

  • creates small + R wave in V1 and small - Q wave in V5
30
Q

in ECG what is the 3RD DEPOLARISATION of

A

VENTRICULAR FREE WALL

  • large + R wave in V5 (towards it)
  • large - Q wave in V1
31
Q

in ECG what is the 4TH DEPOLARISATION of

A

BASAL PART of VENTRICLES

  • small - S wave in V5 (heading away from v5)
    (V1 does not detect this vector)
32
Q

what comes after the 4th DEPOLARISATION in ECG

A

REPOLARISATION

33
Q

T WAVE is CONCORDANT / in the SAME DIRECTION as the QRS WAVE

why is this

A

(depolarisation is detected from endocardium to epicardium)

  • the duration of the ACTION POTENTIAL is SHORTER in EPICARDIAL CELLS
    therefore REPOLARISATION starts in EPICARDIUM towards endocardium
    therefore REPOLARISE EARLIER

the direction of the vectors during depolarisation and repolarisation are opposite but so is the flux of ions therefore there is NO NET DIFFERENCE in the DIRECTION of the electrical vector

34
Q

what is the NORMAL ELECTRICAL AXIS range in ECG

(reflects the average direction of ventricular depolarisation during ventricular contraction)

A

from -30 DEGREES to 90 DEGREES

(to the left and downwards)

35
Q

what is it called if ELECTRICAL AXIS is MORE POSITIVE than 90 DEGREES

A

RIGHT AXIS DEVIATION

36
Q

when does ELECTRICAL AXIS become LEFT AXIS DEVIATION

A

if MORE NEGATIVE than -30 DEGREES

37
Q

SINOATRIAL NODE is SUPPLIED by which ARTERY

A

RIGHT CORONARY ARTERY (in 60% of people)

in 40% of people from Left Circumflex Arterty

38
Q

ATRIOVENTRICULAR NODE is SUPPLIED by which ARTERY

A

RIGHT CORONARY ARTERY (90% people)

(left circumflex in 10% people)

39
Q

RIGHT and LEFT BUNDLE BRANCHES are SUPPLIED by which ARTERY

A

LEFT ANTERIOR DESCENDING (LAD)

may have collaterals from right coronary artery and left circumflex

40
Q

BUNDLE of HIS is SUPPLIED by which ARTERY

A

mainly from RIGHT CORONARY ARTERY

but contributions from septal branches of Left Anterior Descending

41
Q

POSTERIOR FASCICLE activates the inferior and posterior wall

what is it SUPPLIED by

A

PROXIMALLY by RIGHT CORONARY ARTERY
and occasionally septal branches of Left Anterior Descending

DISTALLY by ANTERIOR and POSTERIOR SEPTAL BRANCHES

42
Q

ANTERIOR FASCICLE activates the anterior wall

what is it SUPPLIED by

A

SEPTAL BRANCHES of LEFT ANTERIOR DESCENDING

(very sensitive to ischaemia)

43
Q

RIGHT CORONARY ARTERY detected by which LEADS

A

II, III and AVF

V1, V3R - V6R

44
Q

LEFT CIRCUMFLEX ARTERY observed by which LEADS

A

I, AVL, -AVR

V4 - V9

45
Q

LEADS that observe INTERVENTRICULAR SEPTUM

A

V1 & V2

46
Q

LEADS that observe INFERIOR WALL

A

II, III, AVF

47
Q

LEADS that observe ANTERIOR WALL

A

V3 & V4

48
Q

LEADS that observe ANTEROLATERAL WALL

A

V5 & V6

49
Q

LEADS that observe LATERAL WALL

A

I, AVL, -AVR

50
Q

why are the P and T WAVES SMOOTH but the QRS complex have SHARP SPIKES

A
  • P and T WAVES generated by LOW FREQUENCY SIGNALS
  • QRS complex has much HIGHER FREQUENCY SIGNALS

Cardiovascular (16 decks)

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