EKG

Question 1

Normal QTc Interval

Answer 1

Normal when less than half of R-to-R interval at normal rates

Question 2

each small square represents (time)

Answer 2

0.04 sec

Question 3

each large square represents (time)

Answer 3

0.2 sec

Question 4

lead I

Answer 4

horizontal

L arm electrode is positive

Question 5

lead II

Answer 5

from R arm to L foot

L foot electrode is positive

Question 6

lead III

Answer 6

from L arm to L foot

L foot electrode is positive

Question 7

AVF lead

Answer 7

negative on arms
positive on L foot
vector is 90 degrees down

Question 8

AVR lead

Answer 8

negative on L arm and L foot
positive on R arm
vector is 210 degrees to the R (or -160)

Question 9

AVL lead

Answer 9

negative on R arm and L foot
positive on L arm
vector is -30 degrees to the L

Question 10

“lateral” leads

Answer 10

I and AVL

Question 11

“inferior” leads

Answer 11

II, III, and AVF

Question 12

The center of the “wheel” made by the chest leads is

Answer 12

the AV node

Question 13

which chest lead describes a straight line directly from the front to the back of the patient

Answer 13

V2

Question 14

chest leads oriented over the R heart

Answer 14

V1 and V2

Question 15

chest leads oriented over the L heart

Answer 15

V5 and V6

Question 16

chest leads oriented over the interventricular septum

Answer 16

V3 and V4

Question 17

sinus rhythm

Answer 17

60-100

Question 18

sinus bradycardia

Answer 18

<60

Question 19

sinus tachycardia

Answer 19

> 100

Question 20

atrial automatic foci rate

Answer 20

60-80

Question 21

AV junctional foci rate

Answer 21

40-60

proximal end has no foci

Question 22

ventricular foci rate

Answer 22

20-40

Question 23

u wave

Answer 23

final phase of Purkinje repolarization

Question 24

wandering pacemaker

Answer 24

irregular rhythm
P' wave shape varies
atrial rate less than 100 
irregular ventricular rhythm
can accelerate into tachycardia and becomes Multifocal Atrial Tachycardia

Question 25

irregular rhythm seen in very ill COPD patients

Answer 25

Multifocal atrial tachycardia

Question 26

multifocal atrial tachycardia

Answer 26

``` irregular rhythm P' wave shape varies atrial rate exceeds 100 irregular ventricular rhythm seen in very ill COPD and digitalis tox ```

Question 27

Atrial fibrillation

Answer 27

irregular rhythm continuous chaotic atrial spikes - no P waves irregular ventricular rhythm

Question 28

Atrial and junctional foci become irritable because of

Answer 28

adrenaline increased sympathetic stimulation presence of caffeine, amphetamines, cocaine, or other B1 receptor stimulants excess digitalis, some toxins, occasionally ethanol thyperthyroidism stretch and to some extent, low oxygen

Question 29

ventricular focus can be made irritable by

Answer 29

``` Low oxygen low potassium MVP Stretch Myocarditis ```

Question 30

number of PVC's that is pathological

Answer 30

6 or more in one minute

Question 31

ventricular parasystole

Answer 31

produced by a ventricular automaticity focus that suffers from entrance block but it not irritable paces at its inherent rate the ventricular complexes it generates poke through the dominant sinus rhythm

Question 32

a run of VT that last longer than 30 seconds

Answer 32

"sustained" VT

Question 33

Mitral Valve Prolapse (Barlow syndrome)

Answer 33

causes PVC's including runs of VT and multifocal PVC's considered a benign condition mitral valve is floppy and billows into the LA during systole valves pull and stretch the papillary muscles irritating ventricular automaticity foci

Question 34

tachy-arrhythmia

Answer 34

``` 150-250 = paroxysmal tachycardia 250-350 = flutter 350-450 = fibrillation ```

Question 35

paroxysmal means

Answer 35

sudden

Question 36

PAT with AV Block

Answer 36

rapid rate, spiked P' waves 2:1 ratio of P':QRS Suspect digitalis excess or tox

Question 37

capture beat or fusion beat

Answer 37

During VT, a sinus-paced depolarization stimulus from the atria finds the entire ventricular conduction system receptive to depolarization and produces a normal-appearing QRS(capture beat) atrial depolarization find a receptive AV Node, but ventricular depolarization only proceeds so far before it meets ventricular depolarization progressing from the ventricular focus and normal QRS blends with PVC-like complex(fusion beat)

Question 38

causes of Torsades

Answer 38

low potassium medications that block potassium channels congenital abnormalities (long AT syndrome) ***things that lengthen the QT segment

Question 39

atrial flutter

Answer 39

250-350/min | can have rapid QRS response

Question 40

ventricular flutter

Answer 40

250-350/min rapid series of smooth sine-waves of similar amplitude often deteriorates into V fib

Question 41

fibrillation

Answer 41

multiple foci discharging rapidly 350-450/min a fib - ventricular response is irregular

Question 42

Wolff-Parkinson-White

Answer 42

abnormal, accessory AV conduction pathway = bundle of Kent causes ventricular pre-excitation = delta wave delta wave creates the illusion of a "shortened" PR interval and "lengthened" QRS Can develop paroxysmal tachycardia