Follow-up: Device assessment

Question 1

True / False

Hyperkalemia typically causes loss of atrial capture before loss ventricular capture.

Answer 1

True.

If atrial loss of capture has occurred due to significantly increased thresholds, suspect hyperkalemia.

Question 2

If a patient presents with an unusually wide QRS, what metabolic state should you consider?

Answer 2

Hyperkalemia.

Question 3

True / False

Hyperkalemia decreases stimulation threshold.

Answer 3

False - Hyperkalemia increases stimulation threshold.

Question 4

When looking at the pacing state histogram.

If total % of Ap state (shown as ApVp + ApVs) is greater than all other states, what can be inferred?

Answer 4

A large amount of pacing is likely at the base rate. Suggestive of SSS or Atrial incompetence.

Question 5

When looking at pacing state histogram.

If total % of As state (shown as AsVp + AsVs) is greater than all other states, what can be inferred?

Answer 5

1. If AsVp is large then the condition is likely CHB or the AVD is programmed too short.
2. If AsVs is large then Sinus Rhythm is prevalent and pacemaker is on standby most of the time.

Question 6

When looking at pacing state histogram.

If total % of Vp state (shown as AsVp + ApVp) is greater than all other states, what can be inferred?

Answer 6

Condition is likely CHB or AVD is programmed too short.

Question 7

When looking at pacing state histogram.

If total % of Vs state (shown as AsVs + ApVs) is greater than all other states, what can be inferred.

Answer 7

AV conduction is present in this patient.

Question 8

True / False

A normal P-wave amplitude histogram follows a bell shaped curve distribution.

Answer 8

True.

Question 9

When viewing a P-wave amplitude histogram, there a two distinct groupings. One grouping is larger in amplitude, while another is smaller in amplitude. There is a void of data in-between the two groupings, what is most likely?

Answer 9

1. Signals recorded in the larger amplitude group are likely sinus beats
2. Signals recorded in the smaller amplitude group are likely some form of atrial tachycardia

Question 10

CRT pacing shows dominant RV pacing on an ECG. The patient has CHB, RV and LV thresholds are appropriate and V-V delay is 0ms. What could be occurring at the LV site?

Answer 10

LV exit block or LV conduction delay due to substrate in vicinity of LV electrode.

Question 11

Describe the rhythm on the IEGM.

Answer 11

Atrial Fibrillation with rapid ventricular response.

R-R variability is distinctive of AF. It is impossible to know 100% however as this is a single chamber device. A dual chamber device would allow true discrimination by visualising atrial activity.

Question 12

Describe the rhythm on the IEGM.

Answer 12

Atrial tachycardia with 1:1 conduction.

Question 13

Describe the rhythm on the IEGM.

Answer 13

2:1 AV Block

Question 14

Describe the rhythm on the IEGM.

Answer 14

Atrial Tachycardia.

Question 15

Does this patient likely have CHB or not?

Answer 15

Patient likely has CHB.

Note how there is no conduction of P-waves and Vp throughout the strip. This remains true even when an atrial tachycardia starts.

Question 16

Is this a short duration A-Tach or A-Fib episode?

Answer 16

Short duration A-Tach.

Note how R-R interval is regular. The rate is also too slow to be AF.

Question 17

Describe the rhythm on the IEGM.

Answer 17

Sinus Rhythm.

There is atrial lead noise respondent to lead damage. Unlikely to be EMI interferrence as this would display on both leads.

Question 18

You ask a patient to perform provocation manouvers in clinic and witness this. Both leads are programmed Bipolar. Describe what is happening.

Answer 18

Atrial lead noise likely respondent to lead insulation failure.

Source of noise is likely myopotentials. Unipolar sensing would also give rise to myopotential.

Question 19

Is the device detecting this bipolar lead noise? How best to program around it?

Answer 19

• The atrial lead noise is being detected by the device. This would inhibt output, which could be catastrophic if this was the ventricular lead in a CHB patient.
• Try programming the lead to the unipolar. Retest provocation manouvers in clinic.
• Ultimately a lead revision is necessary.

Question 20

Which conductor has likely failed in the following biploar leads?

Answer 20

Atrial ring conductor has likely failed.

Rarer for the tip conductor to fracture first. This can be tested by programming the lead unipolar tip to can and asessing the IEGM.

Question 21

What is the atrial threshold?

Answer 21

Atrial threshold is 1.5V.

Note how a P-wave is evident on the ECG immediately following the 1.5V stimulus but not evident immediately following the 1.4V stimulus. Note also that an intrinsic P-wave breaks through following the 1.4V stimulus, also indicating non capture.

A reversion to 2.4V inbetween is characteristic of Biotronik threshold testing and should be ignored for the purpose of threshold determination.

Question 22

Describe the rhythm on the IEGM.

Answer 22

Atrial Flutter with variable conduction.

Rhythm is too regular to be AF.

Question 23

Describe the rhythm on the IEGM.

Answer 23

Flutter with 2:1 conduction.

Question 24

What can be said about this rate trend?

Answer 24

Highlights some form of sustained atrial arrhythmia at varying rates.

Patient also likely has CHB as there is little ventricular rate deviation during Tach/Sinus.

Question 25

# Yes / No Is this patient likely to have experienced atrial arrhythmia? If so, which type?

Answer 25

Yes - Atrial Fibrillation. ## Footnote *The top left graph shows atrial rights across the board from 60-400bpm. Due to an even spread its most likely the patient is ecperiencing AF. Flutter or Tach would give bunched As events at a certain rate.*

Question 26

# True / False This patient likely has intrinsic conduction - explain.

Answer 26

False. ## Footnote *Top right graph shows almost all V events are Vp events (white), highly suggestive of CHB. The few Vs events (Black) are likely ventricular ectopics.*

Question 27

The following patient has intrinsic conduction. Whats wrong and how will you correct this?

Answer 27

Patient is almost 100% Vp - extend AV delay or program RVp reduction algorithm. ## Footnote *Not only will this drain battery unnecessarily but will also put patient at risk of pacemaker syndrome.*

Question 28

What is the most likely arrhythmia experienced here?

Answer 28

Most likely AF. ## Footnote *Note how atrial rate is spread out across the whole rate range - thus R-R interval is highly irregular. Also atrial rates above 400bpm are almost always indicative of chaotic firing.*

Question 29

Why are these labeled PVCs when they're clearly organised at regular intervals?

Answer 29

A device will label any V event a PVC if there is no A event preceeding it. ## Footnote *These could very well be conducted Sinus Beats with undetected P-waves by the device or Junctional beats with no preceeding P-wave. The device wont differentiate and instead labels them PVCs.*

Question 30

What is the likely arrhythmia and does this patient likely have intrinsic conduction?

Answer 30

Afib or Aflutter - No intrinsic conduction. ## Footnote *As this is a daily mean average its difficult to know whether the flutter rate was 250bpm or if the highly variable AF rate averaged to 250bpm.* *Look at the V-rate throughout. It is unchanged during/after arrhythmia. Highly suspicious of CHB.*

Question 31

What is the RV threshold?

Answer 31

0.9V. ## Footnote *The V sensed events after 1.2V & 1.1V are ectopic beats. Clear capture can be shown at lower voltages. The stimulus of 0.8V elicits no resonse.*

Question 32

The device registers sinus tachycardia - is this correct?

Answer 32

Yes. ## Footnote *Narrow farfield complex, rates ~150bpm and 1:1 A:V relationship are indicitave of Sinus Tachycardia.* *Onset would be helpful here as gradual onset = Sinus // Sudden onset = Atrial Tachycardia.*

Question 33

What is the RV threshold?

Answer 33

0.6V. ## Footnote *V sensed events following 0.9V stim are likely ectopic beats, clear capture is evidenced at lower voltages.*

Question 34

What is the rhythm shown?

Answer 34

Sinus Rhythm with 1:1 conduction. ## Footnote *The 'extra beat' seen on the atrial channel is infact farfield V sensing. It is likely the Atrial lead is placed close to the tricuspid valve and thus 'sees' ventricular activity.*

Question 35

Why are some of the atrial events labeled with ARs (FFP) and others not?

Answer 35

ARs (Far Field Protection) = PVARP Those without markers = PVAB ## Footnote *Simply those without markers have fallen closer to the preceeding V event and fallen within the blanking period, not the refractory period. Remember the device sees things in the refractory (but doesnt act upon it) and is blind to everything within the blanking period.*

Question 36

# Yes / No The device is labeling the second atrial 'Ars' event with an amplitude - is it only measuring this impluse and missing the first?

Answer 36

No. ## Footnote *The device is not measuring the far field atrial signal, its just the number is formatted to appear in that part of the screen and the far field signal coincidenally lines up (check the V amplitude). The first atrial event is being sensed (and measured) appropriately as seen at the top by the As marker.*

Question 37

What is the likely arrhythmia shown by the IEGM.

Answer 37

VT. ## Footnote *More V than A events, Sudden onset of fast V rate with atrial dissociation, Farfield morphology change.*

Question 38

# True / False The following shows Ventricular Fibrillation.

Answer 38

False. ## Footnote *Ventricular R-R interval is stable, Ventricular amplitude is stable, Farfield morphology change* *No atrial channel so this could (unlikely) be atrial tachycardia with 1:1 conduction*

Question 39

# True / False The following shows Atrial Tachycardia.

Answer 39

False - Most likely Ventricular Tachycardia. ## Footnote *The atrial rate is stable at approximately 90-100bpm* *V rate is ~150bpm, R-R interval is regular, Broad farfield morphology*

Question 40

What arrhythmia is starting here?

Answer 40

Most likely Atrial Fibrillation ## Footnote *Unstable A-A intervals and varying amplitudes are suggestive of AF*

Question 41

Why was the circled Ap delivered despite there being multiple atrial events preceeding it?

Answer 41

The preceeding 3 atrial events were not counted due to either falling within the blanking or refractory periods of the atrial channel.

Question 42

# Yes / No Did the circled Ap event capture, why?

Answer 42

No - fell too soon after a preceeding A-event. ## Footnote *Most likely within the refractory period of the atria, thus unable to initiate a contraction.*

Question 43

What does the IEGM show?

Answer 43

Atrial Tachycardia with 1:1 conduction.

Question 44

You see this in clinic - what is it and what would you do?

Answer 44

Atrial lead noise giving rise to oversensing & inappropriate Mswitch. Immediate doctor consutation.

Question 45

What is the Atrial threshold?

Answer 45

THR = 0.8V. Note how there are P-waves in lead II and II at 0.8V stimuation, but not post 0.7V. ## Footnote *Also see how there is intrinsic atrial breakthrough following the 0.7V stimulation, further alluding to non-capture. The IEGM signal post 0.8V looks different as it is likely a fusion beat.*

Question 46

What behaviour is inappropriate here?

Answer 46

Mswitch has incorrectly resolved as atrial arrhythmia hasn't terminated. ## Footnote *This gives rise to the increase in ventricular rate seen until the Mswitch is again activated - at which point the ventricular rate drops back to the base rate.*

Question 47

What does the IEGM show?

Answer 47

Dropped p-waves giving rise to wenckebach behaviour ## Footnote *P-waves are dropped due to undersensing. Note how dropped p-waves are significantly smaller in amplitude (size on IEGM) than those appropriately sensed and tracked.*

Question 48

# True / False This shows successful ATP.

Answer 48

False. ## Footnote *Note how tachycardia continues afterwards. Note also how farfield morphology and cycle length is unchanged - thus ATP did not enter the tachycardia circuit and alter the arrhythmia in any way.*

Question 49

What rhythm does the IEGM show?

Answer 49

Sinus Rhythm with long 1st degree AVB

Question 50

Why are the V-events labelled 'PVC' when there are clearly A events preceeding them?

Answer 50

The AV delay is grossly extended (480msec) ## Footnote *Thus the device no longer counts the Atrial event as associated to the Ventricular event.*

Question 51

What is the LV threshold?

Answer 51

1.3V

Question 52

Which is the affected lead and what is the likely diagnosis?

Answer 52

LV lead fracture - lead displays make/break connectivity. ## Footnote *High impedance = more likely fracture.* *Low impedance = more likely insulation failure.*

Question 53

# True / False The IEGM shows atrial flutter and CHB - normal function.

Answer 53

False - RV lead shows inappropriate sensing due to noise, thus abnormal function. ## Footnote *The rhythm is indeed atrial flutter with CHB.*

Question 54

What rhythm is shown here, anything unusual?

Answer 54

Likely Sinus Rhythm (regular R-R interval) - RV shows sensed lead noise. ## Footnote *Note how this is counting towards VF and VT counters. If left untreated this could lead to inappropriate therapy.*

Question 55

What type of ATP is this? Was it successful?

Answer 55

Successful burst ATP. ## Footnote *Note rate and far-field electrogram morphology changes pre/post ATP.*

Question 56

# True / False The patients underlying rhythm is atrial fibrillation with CHB

Answer 56

False - Atrial Flutter (regular P-P interval & amplitude) with CHB

Question 57

What is the most likley rhythm displayed here?

Answer 57

Predominantly Atrial flutter (80%) with periods of Sinus p-waves (20%) with CHB throughout. ## Footnote *As grouping on left represents sinus activity, grouping on right represents flutter. Unlikely atrial fibrillation as the grouping is too tight (210-290bpm). Atrial fibrillation would be much wider across all rate ranges.* *CHB as patient is 100% Vp.*

Question 58

Why does the IEGM show Ars (FFP) after every paced beat?

Answer 58

Retrograde P-waves are being conducted and sensed within the PVAB.

Question 59

What is the likely arrhythmia shown here?

Answer 59

Likely AF ## Footnote *Note how the atrial rate is spread across all rate ranges, highlighting irregularity. Flutter would be far more concentrated to a few rate ranges.*

Question 60

What is the likely atrial arrhythmia? Is this conducted to the ventricles?

Answer 60

AF with CHB thus no intrinsic conduction. ## Footnote *Note 100% Vp thus most likely complete heart block patient*

Question 61

What was the most likley indication for this patient?

Answer 61

Chronotropic incompetence - majority of atrial events are paced. ## Footnote *Note how all ventricular events are sensed - intrinsic conduction is present.* *Note also how there is evidence of atrial flutter with 20% of Atrial beats \>250bpm.*

Question 62

# True / False The most likely rhythm is Atrial Flutter with CHB.

Answer 62

True. ## Footnote *100% Vpacing indicates no intrinsic conduction.* *Atrial events are grouped tightly (210-290bpm) suggestive of flutter. Atrial Fibrillation would be across the whole rate range.*

Question 63

What was the shocked rhythm and was the shock successful?

Answer 63

VF - Chaotic & irregular. Successfully terminated with 550V shock.

Question 64

# True / False This patient has intact VA conduction.

Answer 64

True. ## Footnote *Note Ars (FFP) marker post V-events. This is a retrograde P-wave being sensed by the device and falling within the PVAB.*

Question 65

# True / False The rhythm is most likely atrial flutter.

Answer 65

False. ## Footnote *Irregular P-P intervals and alternating p-wave amplitudes alludes to this being Atrial Fibrillation.*

Question 66

# True / False The rhythm is most likely Sinus Tachycardia.

Answer 66

True. ## Footnote *Rhythm shows 1:1 relationship of A and V events. AV and VA intervals remain fixed.*

Question 67

# VT / AF with RVR What rhythm is the most likely diagnosis?

Answer 67

AF with Rapid Ventricular Response. ## Footnote *Atrial fibrillation is clearly shown on the atrial channel. Ventricular response is both rapid and irregular - most likely in response to chaotic atrial intervals being conducted. VT would show far greater R-R stability.*

Question 68

# True / False The following patient doesn't exhibit ventricular conduciton.

Answer 68

False. ## Footnote *Approximately 55% of all ventricular activity is sensed - thus intrinsic conduction must be present, most of the time.*

Question 69

# True / False The following IEGM shows x2 clearly defined NSVT.

Answer 69

False. ## Footnote *The cycle length shows irregularity throughout. This is more likely an example of Atrial Fibrillation with rapid ventricular response.*

Question 70

# True / False The likely tachycardia is Ventricular Tachycardia.

Answer 70

False. ## Footnote *Black squares represent V-sensed events. Black circles represent A-sensed events. Note how they are fixed in-line on the Y-axis at approximately 180bpm and follow one another sequentially. This illustrates A-V synchrony - thus it is likely the rhythm is atrially driven.*

Question 71

# Burst / Ramp Which ATP therapy is employed here?

Answer 71

Burst. ## Footnote *White squares denote V-paced events. Note how the sequence of white squares is in-line on the Y-axis at approximately 240bpm. This illustrates all paced events are at the same cycle length - burst. Remember ramp shortens the cycle length after each beat, which would lead to a upward slope on the dot plot.*

Question 72

What is the likely rhythm?

Answer 72

Ventricular Tachycardia. ## Footnote *Far field electrogram shows a change in morphology, however the underlying arrhythmia is still VT.*

Question 73

Explain why the farfield electrogram changes morphology.

Answer 73

VT can propogate via multiple re-entrant circuits. The example here highlights a change from one VT circuit to a different VT circuit and the corresponding alteration to the electrical signature.

Question 74

# True / False The following IEGM illustrates dual lead fractures.

Answer 74

False - This is an example of external noise. ## Footnote *It is extremely unlikely to get lead noise respondent to fracture to perfectly align on both channels. Noise would be intermittent and out of sync between lead IEGMs on a device with both leads compromised. The fact noise on both leads starts/stops at the same time is suggestive of an external noise source.*

Question 75

What is the ventricular threshold here?

Answer 75

Unable to conclude. ## Footnote *The max output at the start is 2.6V which itself doesn't successfully capture. Thus its impossible to determine the threshold from this IEGM.*

Question 76

# Yes / No Did this device appropriately Mode Switch?

Answer 76

No. ## Footnote *The atrial arrhythmia is clearly on-going after the Mswitch resolved marker. This is due to atrial undersensing, which fools the device into thinking the rate has dropped back below the Mswitch rate.*

Question 77

What is the ventricular threshold?

Answer 77

0.3V ## Footnote *Note how following a 0.2V stim there is no corresponding Vp on the IEGM. Following this a Vs event occurs further corroborating non-capture.*

Question 78

What is the RV threshold?

Answer 78

3.4V ## Footnote *Note how the 3.2V stim does not cause an electrical signal on the FF electrogram.*

Question 79

# True / False The following is characteristic of a steroid eluting lead.

Answer 79

False - Steroid eluting leads have far flatter impedance trends. ## Footnote *Non-steroid eluting leads typically show a rise in impedance up to 6wks post implant due to inflammation at the lead/myocardium interface.*

Question 80

# True / False The rhythm throughout is Sinus Tachycardia.

Answer 80

False. Rhythm starts as Sinus Tachycardia with VT onset. ## Footnote *Note the subtle ventricular rate change, FF morphology alteration and AV dissociation at the 'Onset VT1' marker.*

Question 81

What can be said with respect to the ventricular lead?

Answer 81

Ventricular lead exhibits make/break connectivity, highly suggestive of conductor fracture. ## Footnote *Note how impedance is increasing \>3000ohms. High impedances typically denote fracture, low impedances typically denote insulation failure.*

Question 82

# Yes / No Was this therapy successful?

Answer 82

Yes. ## Footnote *A 650V shock terminated the ventricular arrhythmia.*

Question 83

What is the likely arrhythmia shown here?

Answer 83

VT. ## Footnote *Note stable cycle length and monomorphic appearnce on far-field IEGM.*

Question 84

The following appears to be VT. List a differential diagnosis and explain why.

Answer 84

Could be a form of conducted atrial tachycardia. ## Footnote *Its impossible to say for certain as this is a single chamber device. Without being able to visualise the atrial channel it is impossible to rule out this differential diagnosis.*

Question 85

Is the following Atrial Tachycardia with 1:1 conduction or VT with retrograde conduction?

Answer 85

VT with retrograde conduction. ## Footnote *Arrhythmia starts in the ventricle and immediately conducts to the atrial with a VA conduction time ~120ms.*

Question 86

Why was this ATP unsuccessful?

Answer 86

ATP is designed to resolve ventricular arrhythmias. This IEGM shows an atrial arrhythmia. ## Footnote *Note immediately following ATP therapy there is a VAAV response - this is indicative of atrial arrhythmias, to which the ventricular based ATP was inefffectual at terminating.*

Question 87

Device is programmed VVI 60. List one possible explanation for the observed ~3% pacing at 50ppm.

Answer 87

Night rate. ## Footnote *This allows the device to pace at a rate below the base rate between predefined hours.*

Question 88

What is the likely arrhythmia shown?

Answer 88

Atrial Flutter.

Question 89

# Paroxysmal / Persistent / Chronic The following trend is for 12 months duration. What type of AF is exhibited?

Answer 89

Persistent. ## Footnote *Paroxysmal \<1 week, Persistent \>1 week, Chronic \>1yr.*

Question 90

# True / False This patients pacing indication was likely conduction system disease.

Answer 90

False. ## Footnote *Pacing indication is likely SND / Chronotropic incompetence as evidenced by 100% Ap across the rate range. There is also an ICD indication present denoted by the ventricular therapy zones illustrated.*

Question 91

What two issues can you see here with respect to device function?

Answer 91

1. Ventricular non-capture 2. Ventricular undersensing

Question 92

What rhythm is shown here?

Answer 92

Atrial flutter with CHB.

Question 93

What is the likely terminating rhythm shown here?

Answer 93

Atrial Flutter with CHB. ## Footnote *CHB as pacing rate remains at baseline with little variation.*

Question 94

The following patient remarks of worsening HF symptoms. Why and what can be done to help?

Answer 94

CRT pacing % is low at 66% - Target CRT pacing should be \>97%. ## Footnote *0% Ap events suggests active atrium. 34% AsVs shows atrial conduction which is the reason for our low CRT figure. Breaking the connection between A and V via AVNode ablation would help here.*

Question 95

# Yes / No Based on the IEGM - is this patient likely to be benefiting from CRT?

Answer 95

No. ## Footnote *There are large quantities of V-sensed events observed on this strip. This is due to conducted AF. Remember the goal of CRT is to achieve \>97% CRT pacing.*

Question 96

What is the most likely arrhythmia shown?

Answer 96

Atrial Fibrillation. ## Footnote *Irregularly irregular cycle length. Ventricular arrhythmias would likely present with a broad Far-Field complex.*

Question 97

Explain the following IEGM.

Answer 97

VT with successful termination via shock. ## Footnote *Note broad Far-Field complexes and regular cycle length. VF would be more chaotic and irregular.*

Question 98

Explain the following IEGM.

Answer 98

VT successfully terminated with Burst ATP. ## Footnote *VT as broad FF complexes with fixed cycle length.* *Burst as Vp events have fixed cycle length.*

Question 99

Explain the following IEGM.

Answer 99

VT with failed burst ATP. ## Footnote *VT as broad FF complexes with fixed cycle length.* *Burst as Vp events are fixed cycle length. Note how tachycardia continues afterwards.*

Question 100

# True / False The observed lead noise is due to external sources.

Answer 100

False. ## Footnote *External noise would interfere with and cause noise on both Atrial and Ventricular leads. Noise on one lead isolates the problem to the respondent lead.*

Question 101

What rhythm is shown here?

Answer 101

Non-sustained ventricular tachycardia.

Question 102

What is the ventricular threshold?

Answer 102

0.3V.

Question 103

Describe the arrhythmia and why midway through the Vs events change to PVC events.

Answer 103

Atrial tachycardia ## Footnote *Atrial cycle length accelerates from ~150bpm to ~220bpm. This acceleration causes an atrial event to fall close to the preceeding V event and into its V blanking window (thus A is labeled with Ars FFP). A PVC is classed as any V event without a preceding A event. The device sees no atrial events that fall within the blanking window, thus labels the V event a PVC.*

Question 104

This patient has a DDD device - what is the prevailing rhythm shown here?

Answer 104

Atrial fibrillation with complete heart block. ## Footnote *AF due to broad rate spread across atrial histogram.* *CHB as all V events are Vp events. If there was conduction you would see Vs events - especially with AF due to how rapidly the atrium is firing.*

Question 105

What is the most likely rhythm shown here?

Answer 105

Sinus Tachycardia. ## Footnote *Rhythm is stable with 1:1 AV association. Note the green 'GRADL' marking which denotes gradual increase in rate, not sudden onset, which is consistent with the sinus node.*

Question 106

What rhythm is shown here?

Answer 106

NSVT. ## Footnote *Sudden onset/offset with V sensed events that have a relatively stable cycle length.*

Question 107

What rhyhtm is shown here?

Answer 107

Atrial Tachycardia with CHB.

Question 108

What rhythm is shown here?

Answer 108

SSS with Junctional escape.

Question 109

# True / False The following shows multifocal VT.

Answer 109

False. ## Footnote *Monomorphic VT with two VEs observed.*

Question 110

# True / False The following shows dual tachycardia.

Answer 110

True. ## Footnote *Sinus Tachycardia with 1:1 conduction with the development of VT (note FF complex broadens and V rate overtakes A).*

Question 111

Why is this patient at risk of PMT?

Answer 111

Retrograde P-waves can be seen post BiVp. ## Footnote *Should the PVARP be too short, these retrograde P-waves will be tracked.*

Question 112

# Yes / No Did the device mode switch appropriately?

Answer 112

No. ## Footnote *This is an example of Far-Field R-wave sensing. The R-wave is sensed on the atrial channel, inappropriately triggering the Mswitch.*

Question 113

Patient remarks of SOBOE - what could be the cause?

Answer 113

Ventricular non-capture. ## Footnote *Note how immediately after the Vp maker there is a Vs marker. If the Vp had captured, the ventricle should be refractory and wouldnt be able to depolarize again so quickly.*

Question 114

Which of the following cannot initiate a PMT? 1. Atrial ectopy 2. Ventricular non-capture 3. First degree AVB 4. Atrial undersensing 5. Atrial non-capture

Answer 114

3 - First degree AVB. ## Footnote *Anything that causes AV dyssnchrony can initiate PMT. First degree AVB maintains AV synchrony, thus wont initiate PMT.*

Question 115

What is the rhythm? Is the device function normal?

Answer 115

Atrial Fibrillation - No, the device exhibits atrial undersensing. ## Footnote *Note a lack of tick marks for each atrial event.*

Question 116

You perform the following test in clinic - what is the issue?

Answer 116

Atrial threshold test is giving RV morphology on surface ECG. ## Footnote *Atrial lead has likely dislodged into the RV and is now capturing RV during the Atrial threshold test. X-ray to confirm and immediate reintervention once confirmed.*

Question 117

Patient presents to 6wk post implant check - what do you observe?

Answer 117

Abnormally high impedance values at implant which have stabilized to within normal ranges. ## Footnote *No programming necessary at this stage, check and confirm implant values.*

Question 118

Explain the 'wave pattern' shown in the tachogram.

Answer 118

Sinus Arrhythmia ## Footnote *This is normal behaviour related to the inspiration/expiration cycle. Often observed in younger patients.*

Question 119

# Yes / No Has this device appropriately mode switched?

Answer 119

Yes - Atrial tachycardia appropriately detected. ## Footnote *Note first tachy beat is on the atrial channel with 1:1 AV relationship. Thus atrial not ventricular tachycardia.*

Question 120

# Yes / No Is this appropriate device function?

Answer 120

Yes - IEGM shows DDD with retrograde conduction.

Question 121

# True / False This IEGM shows pacemaker induced VT

Answer 121

False ## Footnote *IEGM shows threshold test initiating a PMT. Note how after the 0.7V Vp, the next signal on A-channel is As. Thus the device tracks this retrograde P-wave and delivers corresponding Vp.*

Question 122

# Yes / No Device in situ for 3yrs. You see the following IEGM in clinic. Is this atrial dislodgement into the V?

Answer 122

No. ## Footnote *As device has been in for 3yrs, the leads will have matured making dislodgement unlikely. IEGM shows Junctional rhythm. AAI pacing reveals true location of Atrial lead.*

Question 123

# True / False This threshold test is being performed in DDD.

Answer 123

False. ## Footnote *Atrial threshold test is being performed in AAI - Note Vs after Ap. If there was a Vp instead of Vs, then the test would be DDD.*

Question 124

What is the threshold?

Answer 124

0.8V ## Footnote *The Ap at 0.7V evokes no response on the atrial IEGM. Capture in AAI also gives rise to a corresponding Vs event. There is no V event, thus the atrium was not captured.*

Question 125

Is there noise present here and is the device oversensing it?

Answer 125

Yes there is noise on the ventricular lead but the device is not sensing it. ## Footnote *Despite not being sensed (no Vs in line with noise). Low amplitude noise such as this requires investigation / provocation manoeuvres.*

Question 126

What is the most likely Arrhythmia seen here?

Answer 126

Atrial Flutter ## Footnote Note how A-sensed rates are largely concentrated to 180bpm. Atrial Fibrillation would have a larger spread across all rates due to irregularity.

Question 127

What is the likely pacemaker indication for this patient?

Answer 127

Complete Heart Block ## Footnote Vp events are >99%, indicating no intrinsic conduction is taking place.

Question 128

What rhythm is shown here?

Answer 128

Complete Heart Block ## Footnote No association between As and Vs events. PR interval constantly changing.

Question 129

The beats circled are listed as PVC's despite the device registering a preceding As event. Why?

Answer 129

Interval from the preceding As event is beyond programmed AVD. ## Footnote Other beats correctly labelled Vs are within the programmed AVD and thus are associated with the preceding As. Those outside the AVD have no preceding As and are hence called PVC.

Question 130

# Yes / No Did this Vp capture?

Answer 130

No ## Footnote Note a lack of waveform on the Farfield channel (top line). The intrinsic V-event afterward is also labelled VF due to short interval between Vp and Vs event. This lead is damaged and requires immediate replacement.

Question 131

# Yes / No Is this VF?

Answer 131

No ## Footnote The device is oversensing noise on the ventricular channel. Intrinsic V-events can clearly be seen corresponding to preceding A-events. The patient is in Sinus Rhythm

Question 132

You see this Pt in ED having received multiple shocks. What rhythm are they in?

Answer 132

Sinus Rhythm ## Footnote Lead is oversensing noise and requires immediate revision. Black line circled denotes device charging and aborting a shock.

Question 133

You see this patient in clinic - what should you do immediately?

Answer 133

Place a magnet over device or de-activate therapies ## Footnote Lead is detecting noise and has misdiagnosed VF. The black bar after 'Det. VF' marker denotes device charing for shock delivery.

Question 134

# Yes / No Was this shock appropriate?

Answer 134

No ## Footnote Device is detecting noise and incorrectly diagnosing VF. Note fractionated signals on RV channel that don't look physiologic in any way.

Question 135

What rhythm is shown here?

Answer 135

Sinus Rhythm ## Footnote Device incorrectly detected onset of VT - this is due to lead noise.

Question 136

# Yes / No Could initial VF detection be set to 30/40 in this case?

Answer 136

Yes ## Footnote This strip shows a re-detect, hence why only 8 VF markers are required to initiate charging. Also note 'RDT. VF' marker. Initial VF detection typically is far longer than this. Lead noise is not relevant to this question.

Question 137

What (if anything) would you draw attention to with this diagnostic report

Answer 137

Atrial lead impedance rise ## Footnote Could be due to calcification of the lead (most likely due to gradual rise) or lead fracture (normally more abrupt increases observed).

Question 138

# Yes / No Does this require emergency admission?

Answer 138

No ## Footnote Pt is dependent, however as this is the Atrial lead its less urgent than if this was the V-lead. Also note how threshold value remains stable despite impedance rise.

Question 139

What (if anything) would you draw attention to with this diagnostic report

Answer 139

Marked increase in short interval count ## Footnote Could indicate an increase of oversensed non-physiologic noise on the lead. Investigate EGMs to confirm. Also note uptick of both impedance and threshold values, which further corroborate lead failure suspicion.

Question 140

# VT / SVT Is this more likely VT or SVT?

Answer 140

SVT ## Footnote See the 1:1 relationship between A and V. Also note highlighted atrial pause causes reciprocal ventriclar pause. If a ventricular driven tachy, the v-rate would continue regardless of atrial pause.

Question 141

What Rhythm is shown here?

Answer 141

Atrial Fibrillation with ventricular pacing

Question 142

What programming changes should be made here?

Answer 142

Tachy therapies turned off ## Footnote Device is detecting RV lead noise and requires revision. Cannot be programmed around without compromising patient safety.

Question 143

Is this VT or AF with RvR?

Answer 143

AF with RvR ## Footnote Instability of V-rate confirms AF with RvR. Shock morphology changes due to going from Vp to Vs, thus unreliable indicator.

Question 144

What is the likely arrhythmia is shown here?

Answer 144

Atrial Tachycardia ## Footnote Note how both Atrial and Ventricular markers increase (squares and circles) above the line. This suggests a 1:1 relationship most commonly seen in SVT's.

Question 145

# Yes / No Is this VT?

Answer 145

No ## Footnote A and V markers increase in rate in a 1:1 fashion. If this was VT only an increase in V markers would be observed.

Question 146

# Yes / No Is this an SVT?

Answer 146

Yes ## Footnote Note how the first beat of the arrhythmia is on the Atrial channel, which then conducts to the Ventricle in a 1:1 fashion.

Question 147

# True / False The device has incorrectly labelled this arrhythmia as an SVT

Answer 147

False ## Footnote This Boston device has correctly labelled this arrhythmia as an SVT using the 'ATR' marker.

Question 148

# True / False This is likely a ventricular arrhythmia

Answer 148

False ## Footnote Both A and V markers have increased in rate in a near 1:1 fashion, heavily suggesting an SVT.

Question 149

What does this dotplot show?

Answer 149

Ventricular tachycardia that accelerates in rate.

Question 150

What phenomena is shown here?

Answer 150

T-wave oversensing

Question 151

List two ways one could program around this.

Answer 151

Increase V-sense threshold start point Increase V-sensing decay delay

Question 152

What is the threshold?

Answer 152

0.7V ## Footnote Note narrow complex following 0.6V pace - indicating intrincic beat, not paced.

Question 153

# Yes / No Was this shock appropriate?

Answer 153

Yes ## Footnote Rhythm is ventricular based (likely VT due to regularity) without atrial involvement (not misdiagnosed SVT).

Question 154

What programming change would you make in response to this?

Answer 154

Shock is at 20J and ineffective, thus programme higher shock output.

Question 155

What induction method is depicted here?

Answer 155

Shock on T.

Question 156

Is this tachycardia likely Atrial or Ventricular?

Answer 156

Atrial ## Footnote Rate change is first noted in the Atrial Channel with the ventricle increasing in rate thereafter.

Question 157

Why has the device labelled this as NSVT?

Answer 157

More sensed V events than A sensed events. ## Footnote This is due to blanking periods making the device 'blind' to atrial events - thus arrhythmia appears V > A to the device.

Question 158

You see this in clinic, what should you do?

Answer 158

LV IEGM shows noise. Program device RV VVI & notify doctor for lead revision.

Question 159

What is the likely device indication for this patient?

Answer 159

Sick Sinus Syndrome - Tachy/Brady

Question 160

Why are these V-sensed events labelled PVC and not Vs?

Answer 160

The AVD is ~400ms. The device wont associate a V-event with an A-event that occured ~400ms ago. ## Footnote Device definition of PVC is V-event without preceding A-event.

Question 161

Is the likely indication CHB?

Answer 161

No - Vp is 4% thus Vp is rarely required, indicating a good AV conduction system.

Question 162

What arrhythmia is shown here?

Answer 162

Atrial Tachycardia. ## Footnote Tachy starts with an A-event, conducts 1:1 and ends with a V-event.

Question 163

What arrhythmia is shown here?

Answer 163

Ventricular Tachycardia. ## Footnote Sudden onset in Ventricular channel with total AV dyssnchrony.

Question 164

What arrhythmia is shown here?

Answer 164

Atrial fibrillation ## Footnote Note chaotic A-sensed intervals, depicting irregularity of the atria.

Question 165

What arrhythmia is shown here?

Answer 165

Ventricular Tachycardia (Non-sustained). ## Footnote Sudden onset / offset of rapid ventricualr events.

Question 166

What arrhythmia is shown here?

Answer 166

Atrial Flutter. ## Footnote Note how regular the atrial events are. Due to regularity this is likely a re-entrant circuit tachycardia.

Question 167

Why is this **not** atrial fibrillation?

Answer 167

Note how regular the atrial events are. Due to regularity this is likely a re-entrant circuit tachycardia. Atrial Fibrillation would be chaotic, with irregular atrial events.

Question 168

What arrhythmia is shown here?

Answer 168

Atrial Fibrillation. ## Footnote Note chaotic A-sensed events, with corresponding irregular V-sensed events. This is AF with periods of rapid conduction up to the VT detect zone.

Question 169

# Yes / No You see this at F/U - is this normal?

Answer 169

No - Atrial lead exhibits gradual impedance rise with abrupt increase at end. Most likely conductor weakening, then finally complete fracture.

Question 170

# Yes / No Is this an example of lead failure?

Answer 170

No - This noise is due to external sources. ## Footnote *Note how noise is present on both channels. It's extremely unlikely to have both leads fail at the same time. This is an example of a police tazer being used.