lecture 2 (chapter 5)

Question 1

describe sinus arrhythmia

Answer 1

normla, but extremely minimal, increase in heart rate during inspiration and an extremely minimal decrease in heart rate during expiration

Question 2

atrial depolarization eventually reaches the AV node, but conduction of depolarization slows within the AV node, recording a ______ on EKG

Answer 2

pause

Question 3

when the ventricular myocardium depolarizes, it produces a ____ on EKG

Answer 3

QRS complex

Question 4

what is a wandering pacemaker

Answer 4

an irregular rhythm (normal rate range)

Question 5

what a rhythm of patients with chronic obstructive pulmonary disease. The heart rate is over 100 per minute with P waves of various shapes, since 3 or more atrial foci are involved

Answer 5

multifocal atrial tachycardia

Question 6

what does atrial fibrillation result from

Answer 6

multiple irritable atrial foci, suffering from entrance block, pacing rapidly

Question 7

when is an automaticity focus overdrive-suppressed

Answer 7

if it is regularly depolarized by a pacing rate fasting than its own inherent pacing rate

Question 8

what syndrome occurs when there is pacing from a ventricular focus that is so slow that blood flow to the brain is significantly reduced to the point of unconsciousness

Answer 8

stokes-adams syndrome

Question 9

what are the most sensitive O2 sensors

Answer 9

ventricular automaticity foci

Question 10

a premature atrial beat may be unable to depolarize the AV node if it (the AV node) is not fully depolarized and still _______ to an extra stimulus

Answer 10

refractory

Question 11

an irritable junctional automaticity focus may fire a premature stimulus coupled to the end of each normal (SA node paced) cycle to produce ________

Answer 11

junctional bigeminy

Question 12

an irritable junctional focus may fire a stimulus after 2 consecutive, normal sinus-generated cycles. a repeating series of these couplets is ___________

Answer 12

junctional trigeminy

Question 13

the most likely reason for a ventricular automaticity focus to become irritable is ________

Answer 13

hypoxia

Question 14

a solitary ventricular focus suffering from entrance block is ________

Answer 14

parasystolic

Question 15

what is the rate range for paroxysmal tachycardia

Answer 15

150 to 250

Question 16

what is the rate range for flutter

Answer 16

250 to 350

Question 17

what is the rate range for fibrillation

Answer 17

350 to 450

Question 18

what does paroxysmal mean

Answer 18

sudden

Question 19

sudden runs of ventricular tachycardia resemble a rapid series of_____

Answer 19

PVCs

Question 20

paroxysmal ventricular tachycardia often indicates ______

Answer 20

coronary insufficiency

Question 21

the accessory __________ causes ventricular pre-excitation in wolfs-parkinson-white syndrome

Answer 21

bundle of kent

Question 22

the delta wave records the ___________

Answer 22

depolarization of an area of ventricular pre-excitation

Question 23

what is the ability of specialized cells to spontaneously generate electrical impulses which may then spread throughout surrounding tissue

Answer 23

automaticity

Question 24

what is the rate for atrial foci

Answer 24

60-80 per minute

Question 25

what is the rate for junctional (AV nodal) foci

Answer 25

40-60 per minute

Question 26

what is the rate for ventricular foci

Answer 26

20-40 per minute

Question 27

what term describes the content that the pacemaker with the fastest rate is the dominant pacemaker

Answer 27

overdrive suppression

Question 28

describe the P wave in a sinus rhythm

Answer 28

positive in lead 2 and negative in lead aVR

Question 29

what is the EKG criteria for a normal sinus rhythm

Answer 29

sinus rhythm with a heart rate between 60 and 100 beats per minute

Question 30

what is the EKG criteria for sinus arrhythmia

Answer 30

same criteria as sinus rhythm and there is a greater than 0.16 sec difference between the shortest and the longest PP intervals within the same EKG tracing

Question 31

what is the most common cause of sinus arrhythmias

Answer 31

respiration

Question 32

what is the key to determining the origin of a completely inverted P wave in lead 2

Answer 32

length of the PR interval (provided that there is no AV nodal dysfunction)

Question 33

describe bigeminy

Answer 33

every other beat is premature

Question 34

describe trigeminy

Answer 34

every 3rd beat is premature

Question 35

what is enhanced automaticity due to

Answer 35

irritability

Question 36

describe torsades de pointes

Answer 36

polymorphic ventricular tachycardia (VT) which is preceded by marked prolongation of the QT interval

Question 37

what is tornadoes de points facilitated by

Answer 37

marked QT prolongation

Question 38

what is the most common mechanism of tachyarrhythmias

Answer 38

reentry (disorder of impulse propagation)

Question 39

what does reciprocating tachycardia result from

Answer 39

unidirectional block followed by re-entry

Question 40

what are the main criteria for wandering pacemaker

Answer 40

irregular rhythm: P wave shape varies, atrial rate less than 100, irregular ventricular rhythm

Question 41

what is the main criteria for multifocal atrial tachycardia

Answer 41

irregular rhythm: P wave shape varies, atrial rate exceeds 100, irregular ventricular rhythm