Bb Pacing

Front 1

What is the 5 letter code for pacers?

Back 1

position 1 chamber paced,
position 2: chamber sensed;
position 3: response to sensing;
position IV: programmability, rate modulation;
position V: antitachycardia fxn

Front 2

When would you not want to use ventricular demand pacing (VVI, VVT)?

Back 2

if AV synchrony (atrial kick) is needed to improve end diastolic filling of the LV

Front 3

When would you use a VDD setting?

Back 3

AV block with a normal atrial rate

Front 4

when would you use AAI or AAT setting

Back 4

nml AV conduction with atrial bradycardia
-in the setting of sinus node dysfunction, including sinus arrest, sinus block, and sick sinus syndrome

Front 5

When would you use DVI setting?

Back 5

AV block with atrial bradycardia

Front 6

what are rate responsive pacemakers?

Back 6

VVIR, DVIR, DDDR;
-have the capacity to sense atrial and ventricular activity as well as other stimuli;
-increased CO can be achieved with increased O2 consumption, increased catecholamines, increased temp

Front 7

What are programmable features on pacemakers?

Back 7

1. rate - upper and lower rates are usually set
2. stimulus output,
3. sensitivity,
4. refractory period,
5. antitachycardia modes

Front 8

What are indications of preop pacemaker malfunction?

Back 8

1. syncope,
2. dizziness,
3. fatigue,
4. chest pain,

Front 9

When should you consider placement of a pacemaker in the abdominal position?

Back 9

-usually it is placed over the pectoralis muscle,
-in some patients during physical activity inhibition occurs because myopotentials are sensed
-if this is a significant problem use the abdominal position

Front 10

Why should you not routinely place a magnet over a pacemaker during surgery with electrocautery?

Back 10

pacemaker can be unpredictably reprogrammed and it would not be evident until the magnet is removed

Front 11

What pacemakers can be reprogrammed by cautery or inhibited by myopotentiials or fasciculations?

Back 11

demand pacemaker

Front 12

How should you deal with rate responsive pacemakers prior to surgery?

Back 12

have the rate responsive mode deactivated prior to surgery

Front 13

How can evoked potential monitoring affect pacemakers?

Back 13

-can interfere for pacer function
-patients with VDD or DDD can develop tachycardia in the presence of evoked potentials, peripheral nerve stimulators, or transcutaneous electical stimulators
-these modes should be changed to VVI or VOO

Front 14

How does lithotripsy affect pacer fxn?

Back 14

usually it's safe with pacers,
- the focal point of the lithotriptor should be kept 6 inches from the pacer

Front 15

If a MRI must be done in a patient with a pacer how should you handle the pacer?

Back 15

if patient is not pacer dependent, pulse generator should be turned off (000) or explanted

Front 16

How does radiation therapy affect pacemaker use?

Back 16

radiation therapy can damage the pacer in unpredictable ways,
-pacer fxn should be evaluated

Front 17

How does hypo or hyperkalemia affect pacer fxn?

Back 17

-hypokalemia can lead to loss of capture;
-hyperkalemia can lead to ventricular irritability

Front 18

What are pacemaker indications?

Back 18

1. third degree heart block,
2. acute MI with type II mobitz block,
3. severe symptomatic sinsu bradycardia,
4. symptomatic bifascicular block,
5. any sig bradycardia with heart block

Front 19

How do you test a demand pacemaker?

Back 19

valsalva or carotid massage to decrease HR and see if pacemake kicks in
-if this does not decrease rate sufficiently, a magnet can be applied to convert the pacemaker to an asynchronous mode

Front 20

How can you tell if there is LA hemiblock?

Back 20

LAD + slight QRS widening

Front 21

How can you tell if there is a left posterior hemiblock?

Back 21

RAD + widening of QRS

Front 22

What are indications for AICD?

Back 22

1. patient's who survive sudden death episodes,
2. sustained VT,
3. syncope due to VT,
4. arrhythmias not amenable to ablation

Front 23

What are the meanings of the 4 letter codes for AICD?

Back 23

position 1: shock chamber
position 2: antitachycardia pacing chamber
position 3: tachycardia detection (electrogram or hemodyn)
position 4: antibradycardia pacing chamber

Front 24

Why should you be careful about using a magnet in a patient with an AICD?

Back 24

some ICDs can be deactivated in patient's with a magnet, others require programmed deactivation,
- ICD over a magnet can lead to unpredictably reprogramming or discharge

Front 25

If deactivation of an AICD does not occur what can happen during surgery with an electrocautery?

Back 25

ICD can interpret electrocautery as a dysrrhythmia and discharge

Front 26

If an ICD is deactivated correctly preop what pacing can remain active?

Back 26

VOO, VVI

Front 27

How is lithotripsy affected in patients that have an AICD?

Back 27

lithotripsy should be avoided unless it has been deactivated

Front 28

How does evoked potential monitors and peripheral nerve stimulators affect AICDs?

Back 28

interfere with ICDs and cause them to discharge

Front 29

In patients with AICDs what should you have available in the room?

Back 29

external defibrillating device

Front 30

If electrocautery is to be used in a patient with an AICD or pacer what should you determine?

Back 30

determine if reprogramming, conversion to asynchronous mode, and/or disabling rate responsive function is an advantage;
-in general suspend antiarrhythmia functions;
-have surgeon use bipolar cautery or harmonic scapel,
-have surgeon use short intermittent bursts of bipolar cautery

Front 31

How should you manage a radiofrequency ablation in a patient that has a pacer or an AICD?

Back 31

keep the radiofrequency current path as far as possible from the CRMD

Front 32

In a patient that needs radiation therapy in the same location as the pulse generator of an AICD or pacer what should you do?

Back 32

have surgeon put the pulse generator somewhere else

Front 33

What should you do in a patient getting ECT that has a pacer or AICD?

Back 33

consult with a cardiologist

Front 34

Why should you worry about a patient being paced in an asynchonous mode in a patient with an intrinsic rhythm?

Back 34

pacer can fire on a T wave and can induce VT or VF

Front 35

Prior to surgery should you have a rep convert the pacemaker to an asynchronous mode or place a magnet over it?

Back 35

need to know rhythm prior to surgery and whether pacer should be reprogrammed to not pace at all or whether a magnet converting the pacer to asynchronous mode is advisable

Front 36

What do the first 3 letters of the pacemaker code describe?

Back 36

the antibradycardia functions

Front 37

What do the last 2 letters of the pacemaker code describe?

Back 37

programmability and anti-tachycardia functions

Front 38

What if the last 2 letters have no designation?

Back 38

then the 1st 3 letters are used alone

Front 39

What are the fixed rate or asynchronous modes?

Back 39

VOO
AOO
DOO

Front 40

Describe the asynchronous mode.

Back 40

-paces but does not sense the atrium, ventricle, or both chambers
-may compete with the intrinsic rhythm resulting in afib or aflutter, and in pacemaker firing on the T wave of the ventricle - not generally a problem in absence of myocardial ischemia or electrolyte abnormalities

Front 41

Describe a demand or synchronous pacemaker mode.

Back 41

pacemaker senses the atrial impulse (P wave), ventricular impulse (R wave), or both.
-pacemaker is either triggered (fires) or inhibited by the sensed signal

Front 42

What are considered the atrial demand/synchronous pacemakers? Describe.

Back 42

AAI
AAT
-atrium is paced and sensed, either inhibited or triggered
-an intact AV conduction system is utilized to achieve ventricular depolarization

Front 43

Describe ventricular demand or synchronous pacing.

Back 43

VVI or VVT
-ventricle is paced or sensed and either triggered or inhibited
-pacing is characterized by no AV synchrony, indicated in the setting of AV node dysfunction or presence of supraventricular arrhythmias

Front 44

What are the dual chamber demand or synchronous pacemakers?

Back 44

VAT
VDD
DVI
DDD

Front 45

Describe dual chamber demand pacemakers.

Back 45

-Ensures coordinated AV synchronous depolarization of the heart
-sinus node function must be normal in a pt with abnormal AV nodal function

Front 46

What do VAT and VDD modes pace?

Back 46

the ventricle after sensing atrial activity

Front 47

What does the DDD mode provide?

Back 47

-for "AV universal pacing", both the atrium and ventricle are paced and both are sensed
-there is a preset AV interval and synchronized atrial and ventricular depolarization in pts with varying intrinsic atrial and ventricular rates

Front 48

Where should the bovie be in regards to location?

Back 48

- as far from the pulse generator and as close to the site of surgery and to the return pad as possible

Front 49

What are EKG findings of pts with pacemakers?

Back 49

- atrial pacemaker: atrial spike
- ventricular pacemaker: spike immediately before the ventricular complex
- AV sequential pacemaker: two spikes

Front 50

Describe first degree heart block?

Back 50

PR interval >= 0.2 seconds

Front 51

Mobitz type I second degree heart block

Back 51

AKA Wenkebach
-progressive prolongation of the PR interval until a beat is dropped

Front 52

Mobitz type II second degree heart block

Back 52

sudden dropping of the QRS without warning

Front 53

Right bundle branch block

Back 53

-QRS >=0.12
-Look for R-S-R in leads V1 and V2
-does not imply cardiac disease

Front 54

Left bundle branch block

Back 54

-implies CAD, HTN, or LVH
-in its presence, EKG diagnosis of an acute MI is difficult

Front 55

3rd degree heart block

Back 55

atrial beat bears no relationship to ventricular beat

Front 56

How do you workup or initially evaluate a pt with a pacemaker?

Back 56

1. Determine whether the pt has a cardiac rhythm management device (CRMD) - hx, med records, CXR EKG
2. Determine the type of CRMD - manufacturer's card, check on-line database, CXR
3. Determine CRMD function - have cardio or pacemaker service interrogate the device
4. Determine pt dependency upon the CRMD

Front 57

What is preoperative preparation for a pt with a CRMD?

Back 57

1. ensure availability of temporary pacing and defibrillation equipment
2. If electromechanical interference is to be used, determine if reprogramming, conversion to asynchronous mode, and/or disabling rate responsive function is an advantage
3. Suspend anti-arrhythmia functions
4. Advise surgeon to use bipolar cautery if possible and/or harmonic scalpel

Front 58

What is the intraoperative management of a pt with a CMRD?

Back 58

1. monitor EKG and peripheral pulses (pulse ox, A-line) continuously
2. manage CRMD dysfunction due to EMI
3. Prepare for emergency defibrillation or cardioversion

Front 59

How should you manage a lithotripsy pt with a pacemaker or AICD?

Back 59

-Avoid focusing the lithotripsy beam on or near the pulse generator
-if the lithotriptor triggers on the R wave, atrial pacing should generally be disabled, consult with cardiologist

Front 60

What happens when a magnet is placed over a medtronics AICD?

Back 60

magnet suspends shocking function of an AICD for a detected high rate, but it does not affect the pacing function (for bradycardia) at all

Front 61

What happens when a magnet is placed over a medtronics pacemaker?

Back 61

magnet converts the pacemaker to an asynchronous mode
-when the magnet is removed, the pacemaker goes back to normal operation
-can be deleterious if hte pacer fires on a T wave in a pt with an intrinsic rhythm as this can induce VT or VF

Front 62

What happens if you place a magnet on a Boston Scientific pacemaker?

Back 62

Flips a switch to 1 of 3 positions
1. asynchronous mode - mainly to check battery, good mode in the presence of EMI so pacer won't be inhibited
2. magnet has no effect mode
3. store e-gram (EKG) mode - used when pts have palpitations or other symptoms which may be attributable to devise, makes possible to r/o pacer as cause of the problem

Front 63

Taping a permanent magnet provided with the pacemaker to the skin over an implanted demand pacemaker will....

Back 63

Convert the pacemaker to an asynchronous mode

Front 64

What is the asynchronous heart rate set for each brand of pacemakers?

Back 64

-Boston Scientific - 100 bpm
-Medtronic - 65 bpm
-St. Jude - 97 bpm
-as battery life is depleted, asynchronous rates will slow

Front 65

How will electrodes present in the atrium appear on EKG? Right ventricle? Left ventricle?

Back 65

-atrium - will create P waves
-right ventricle - LBBB
-left ventricle - RBBB

Front 66

What are the causes of pacemaker failure?

Back 66

1. hypokalemia will cause loss of capture
2. hyperkalemia will causes VT or VF
3. MI
4. hypoxia
5. acidosis
6. myopotential inhibition - sux or shivering
7. electrocautery