EKGs

Question 1

what produces the P-wave?

Answer 1

atrial depolarization

Question 2

what wave marks the beginning of one cardiac cycle?

Answer 2

p-wave

Question 3

what node generates the p-wave?

Answer 3

SA node

Question 4

the PR interval represents what?

Answer 4

time from start of atrial depolarization to start of ventricular depolarization

Question 5

The AV node is generated during which interval?

Answer 5

PR interval

Question 6

what does the QRS complex represent?

Answer 6

ventricular depolarization

Question 7

what action is happening during the ST segment?

Answer 7

mechanical contraction of ventricles

Question 8

the T-wave represents what?

Answer 8

ventricular repolarization

Question 9

how does hyperkalemia affect the t-wave?

Answer 9

t-wave will be larger than the QRS complex

Question 10

The QT interval refers to what set of actions?

Answer 10

ventricular depol, ventric contrac., & ventric. repol.

Question 11

prolonged QT interval increases risk of what?

Answer 11

ventricular arrhythmias

Question 12

what drugs can cause prolonged QT intervals?

Answer 12

macrolides; haloperidol, TCAs, odansetron; azoles

Question 13

which EKG leads are going to have a negative QRS complex assuming no cardiopathy is present?

Answer 13

aVR, V1-V3

Question 14

which leads correspond to the RCA?

Answer 14

II, III, & aVF

Question 15

which leads correspond to the LAD?

Answer 15

V1-V4

Question 16

which leads correspond to the LCX?

Answer 16

V5, V6, & aVL

Question 17

ST elevation is an indication of what?

Answer 17

transmural ischemia

Question 18

ST depression is an indication of what?

Answer 18

subendocardial ischemia

Question 19

the aVL lead corresponds to which other leads?

Answer 19

I, V4-V6

Question 20

the aVF lead corresponds to which other leads?

Answer 20

II, III

Question 21

Lead I & aVF are both positive represents what?

Answer 21

a normal axis

Question 22

+ Lead I & -aVF is associated with what cardiopathy?

Answer 22

possible LAD

Question 23

negative Lead I & + aVF indicates what cardiopathy?

Answer 23

RAD

Question 24

An inferior MI is associated w/ which coronary artery?

Answer 24

RAD (left ventricular hypertrophy)

Question 24

An anterolateral MI is associated w/ which coronary artery?

Answer 24

LAD (right ventricular hypertrophy)

Question 25

Would hypokalemia reduce or elevate the t-wave?

Answer 25

reduce it

Question 26

What is a normal QT interval quantitatively defined as?

Answer 26

less than half of the R-R (peak to peak) interval

Question 27

SA depolarization is not detected on a wriggers' diagram. atrial depolarization (p-wave) always precedes atrial contraction which represent what wave?

Answer 27

a-wave

Question 28

the a-wave is due to an increase in atrial pressure associated w/ contraction; when will atrial pressure increase again

Answer 28

during ventricular contraction; atrial pressure will increase as seen on the c-wave

Question 29

ventricular contraction/systole begins b/t the a & c waves; what is happening to the ventricular pressure & volume during this time?

Answer 29

pressure is rising while volume is left unchanged; isovolumetric contraction phase

Question 30

Describe the pressure differences in heart chambers during Atrial Diastole?

Answer 30

LA pressure > RA pressure; VC pressure will be greater than both LA & RA; atrial pressure is slightly higher than ventricular pressure to permit blood flow from the atrium into the ventricle

Question 31

during ventricular contraction, what is happening to the volume?

Answer 31

ventricular volume is decreasing

Question 32

Ventricular Systole starts and ends b/t which two points of the cardiac cycle on a wriggers' diagram?

Answer 32

QRS complex & end of t-wave

Question 33

during rapid ejection phase, what is happening b/t the atria & ventricles?

Answer 33

V pressure > A pressure; this opens up the semilunar valves of the aorta & pulmonary arteries; ventricular isotonic contraction

Question 34

during reduced ejection phase, what is happening with the ventricles?

Answer 34

LV pressure falls below AO & PA pressures; blood is still being ejected from the ventricles; in this phase, inertia rather than the pressure is driving blood out of the ventricles; coincides w/ t-wave

Question 35

when does ventricular systole end?

Answer 35

when the semilunar valves close; at the end of the reduced ejection phase

Question 36

What is happening during ventricular diastole?

Answer 36

Atrium pressure > Ventricular pressure causes AV valves to open; ventricles are relaxed and start filling w/ blood

Question 37

when does ventricular diastole end?

Answer 37

at beginning of next p-wave & reappearance of the R-wave

Question 38

S1 is associated w/ closure of which valves & during which part of the cardiac cycle is it heard?

Answer 38

AV closure; start of ventricular systole; QRS complex

Question 39

S2 is associated w/ closure of which valves & during which part of the cardiac cycle is it heard?

Answer 39

semilunar valve closure; beginning of ventricular diastole

Question 40

S3 can be heard during which part of the cardiac cycle and in what pts. is it usually heard?

Answer 40

rapid filling phase of ventricular diastole; pediatric pts.

Question 41

S4 is associated w/ which part of the cardiac cycle and what is it an indication of?

Answer 41

would be heard at start to atrial systole and is indicative of a hypertrophied ventricle

Question 42

preload is referred to as what?

Answer 42

the end diastolic volume

Question 43

what is the equation for Laplace Law?

Answer 43

wall tension = (pressure x radius)/thickness

Question 44

What leads produce a positive QRS complex?

Answer 44

I, II, III, aVF, aVL, V4-V6

Question 45

What are the left leads?

Answer 45

I, aVL, V4-V6

Question 46

what are the right leads?

Answer 46

III, aVR, & V1-V3

Question 47

Leftward axis deviation is associated w/ which type of MI and what is the gross pathologic finding?

Answer 47

Gross pathology: left ventricular hypertrophy; Leftward deviation associated w/ Inferior MI

Question 48

Rightward axis deviation is associated w/ which type of MI & what is the gross pathologic finding?

Answer 48

Gross pathology: right ventricular hypertrophy; rightward deviation associated w/ anterolateral MI

Question 49

What are prolonged PT intervals associated with & what is the normal range?

Answer 49

Norm: <200 ms; prolonged PT intervals are associated with AV blocks