Pacemakers.

Question 1

almost always on the

Answer 1

right side of the heart.

Question 2

indications for pacing:

Answer 2

symptomatic complete heart block, asymptomatic complete heart block, symptomatic sinus bradycardia (sick sinus syndrome), chronic incomplete heart block, persistent advanced heart block in acute MI, symptomatic congenital heart block, complete heart block.

Question 3

benefits of pacing:

Answer 3

healthy heart rhythm = increased cardiac output = improves cerebral and total body perfusion = symptomatic relief = patient benefits.

Question 4

pacemakers:

Answer 4

control discharge, time discharge, and recognize native activity of the heart.

Question 5

tip electrode:

Answer 5

delivers a stimulus to the myocardium and detects native intra-cardiac signals.

Question 6

unipolar leads

Answer 6

negative in heart

Question 7

bipolar leads

Answer 7

positive and negative in heart

Question 8

voltage:

Answer 8

potential (force) capable of doing work; battery voltage is a function of the mounts of charged material placed inside the battery cell by the manufacturer.

Question 9

higher voltage =

Answer 9

stronger push on electrons.

Question 10

resistance:

Answer 10

an opposition to current (tries to stop the flow).

Question 11

low resistance =

Answer 11

high current.

Question 12

high resistance =

Answer 12

low current. fibrosis, scarring.

Question 13

resistance is:

Answer 13

primarily a function of cardiac tissue and electrode position.

Question 14

current:

Answer 14

the flow of electrons leaving the battery (pacemaker); garden hose analogy; measured in milliamperes; program the voltage to get the current.

Question 15

current vs voltage:

Answer 15

current is a result of voltage; it is not controlled or programmed nor can it be changed directly; current is indirectly controlled via programmable voltage (the greater the push, the greater the flow).

Question 16

Ohm’s law

Answer 16

voltage = current x resistance.

Question 17

stimulation threshold

Answer 17

the minimum output voltage that consistently achieves capture outside the heart’s refractory period; the pulse width at which the output voltage achieve capture.

Question 18

when setting voltage:

Answer 18

turn down until you lose stimulation, turn up until consistent, turn up 1.5x that to ensure consistent delivery.

Question 19

capture:

Answer 19

depolarization of cardiac muscle following an electrical stimulus; considered abnormal because it is out of the normal conduction pathway.

Question 20

sensitivity:

Answer 20

the degree that the pacing system “sees” or senses signals; it is controlled by the sensitivity setting which in in graduated millivolts; makes sure it doesn’t fire if it isn’t supposed to.

Question 21

types of generators:

Answer 21

asynchronous, demand, and dual chamber.

Question 22

asynchronous:

Answer 22

not in sync, just at a fixed rate w/o respect to what the patient is doing; non-demand; hardly used because it is dangerous (pacemaker spike and patients own heart rate).

Question 23

demand:

Answer 23

sense natural electrical activity of the heart and fire only when needed. paces when the patient’s heart is slower than the pacemaker; pacing the atria preserves the atrial kick. can be atrial or ventricular.

Question 24

dual chamber:

Answer 24

VAT, DVI, VDD, DDD.

Question 25

methods of pacing:

Answer 25

transthoracic, epicardial, and transvenous.

Question 26

transthoracic pacing:

Answer 26

vests.

Question 27

epicardial pacing:

Answer 27

screw into epicardium through the thoracic and into a battery pack (after heart surgery).

Question 28

transvenous pacing:

Answer 28

temporary or permanent.

Question 29

biventricular pacing:

Answer 29

uses three leads; placed in the RA. RV, and LV (BBB).

Question 30

temporary pacing indications:

Answer 30

sick sinus syndrome, heart block, drug-refractory dysrhythmia, cardiovascular surgery, diagnostic uses.

Question 31

sick sinus syndrome:

Answer 31

patient must by symptomatic and documented with EKG: symptomatic sinus bradycardia, symptomatic sinus arrest, suppression of ventricular ectopy resulting from bradycardia, Afib, brady/tachy.

Question 32

heart block:

Answer 32

type 1 & 2 with second AV block, acute bifascicular or trifascicular block, complete AV block, cardiac arrest with ventricular systole.

Question 33

drug-refractory dysrhythmia:

Answer 33

overdrive ventricular pacing to suppress/prevent ventricular ectopic activity; overdrive atrial pacing to 'brea' SVT or Aflutter.

Question 34

cardiovascular surgery:

Answer 34

coverage for anesthesia and surgery in patients with cardiac history; treatment of complete heart block developed during surgery; augment cardiac output post op.

Question 35

diagnostic uses:

Answer 35

sick sinus syndrome pacing studies to determine SA node recovery; stress test for CAD; EP studies.

Question 36

pacemaker code:

Answer 36

chamber paced, chamber sensed, mode of response, programmability, anti-iachycardia.

Question 37

chamber paced

Answer 37

a, v, d, or 0.

Question 38

chamber sensed

Answer 38

a, v, d, or 0.

Question 39

mode of response

Answer 39

i, t, or d.

Question 40

programmability

Answer 40

p(simple), m(multi), c(communicating), r(rate-modulating), 0.

Question 41

anti-iachycardia functions

Answer 41

p(pace), s(shock), d(both).

Question 42

complications:

Answer 42

failure to capture, failure to sense.

Question 43

loss of capture

Answer 43

dislodged lead, perforation, exit block, insulation break.

Question 44

twiddler's syndrome:

Answer 44

patient will twiddle with pacemaker and dislodge it; shoulder immobilized after surgery. turn up MA, fix the lead.

Question 45

over-sensing

Answer 45

inhibition of the pacemaker by events the pacemaker should.

Question 46

under-sensing

Answer 46

failure of the pacemaker to sense intrinsic R waves or P waves; if fires too soon, may hit T wave.

Question 47

complications of subclavian puncture

Answer 47

pneumothorax, subclavian artery injury, brachial plexus injury, bony spicules on the clavicle, hematoma, air embolism, thrombosis, and infection.

Question 48

electromagnetic interference

Answer 48

anything significantly electromagnetic, can't have MRI, theft detector gate, car engine, jumper cables, defibrillation, electrosurgery, electrocautery, diathermy, u/s therapy; stay 1-2 inches away when defibrillating.