SCGH CME ICD / Pacemaker Talk

Darren Bond - Medtronic

29th Jan 2015

Objectives

• Discuss common reasons for ED

checks and outcomes

• Show a device interrogation

• Go through magnet operation for

ICD and PPM’s

• Give overview of CareLink Express

(CLE) status in WA

• What's new

o MRI devices

o Injectable loop recorders

o Leadless pacemakers

Common Reasons for Device Checks in ED

• Syncope – 100% get the device checked

• Palpitation

• Device Beeping

• Shock from their device (include Pseudo shocks)

• Pacing spikes where they shouldn’t be

• Patient feeling unwell

• Pseudo malfuctions

Device interrogation

• Pacemaker

• Loop

• ICD

Pseudomalfunctions

• ECG findings that appear to result from pacemaker

malfunction but that represent normal pacemaker function

• Defined as Unusual, Unexpected, Eccentric

Pseudomalfunctions Rate

Rate Changes May Occur Due to Normal Device Operation:

• Magnet operation

• Timing variations (A-A versus V-V timing)

• Upper rate behavior (Pseudo-Wenckebach; 2:1 block)

• Electrical reset (may occur due to exposure to electromagnetic interference (EMI) –

e.g., electrocautery, defibrillation, causing reversion to a “back-up” mode)

• Battery depletion

• Device intervention algorithms (PMT, NCAP, PMOP, etc.)

• Rate response

• Therapy (Hysteresis, Rate drop response, Mode switching, MVP, etc.)

Pseudomalfunctions Rate

Rate Changes May Occur Due to Normal Device Operation:

• Magnet operation

• Timing variations (A-A versus V-V timing)

• Upper rate behavior (Pseudo-Wenckebach; 2:1 block)

• Electrical reset (may occur due to exposure to electromagnetic interference (EMI) –

e.g., electrocautery, defibrillation, causing reversion to a “back-up” mode)

• Battery depletion

• Device intervention algorithms (PMT, NCAP, PMOP, etc.)

• Rate response

• Therapy (Hysteresis, Rate drop response, Mode switching, MVP, etc.)

PseudomalfunctionsRate Examples

Magnet

Pseudo-

Wenckeback

Operation

2:1 Block

Operation

PMT Intervention

Rate Response

Pseudomalfunctions:

• May appear anomalous due to:

o MVP Mode

o Safety pacing

o Blanking

o Rate-adaptive AV delay

o Sensor-varied PVARP

o PVC response

o Noncompetitive atrial pace (NCAP)

PseudomalfunctionsAV Intervals/Refractory periods Examples

Ventricular Safety Pace

MVP Mode

PAV delay with no activity PAV with activity

Rate Adaptive

AV Delay

PseudomalfunctionsPacing Modes

May Be Caused By:• Battery depletion indicators (ERI/EOL)

• Electrical reset

• Mode switching

• Noise reversion

o Sensing that occurs during atrial or ventricular refractory periods will

restart the refractory period.

o Continuous refractory sensing is called noise reversion and will:

• Cause pacing to occur at sensor-indicated rate for rate-responsive modes

• Cause pacing to occur at the lower rate for non- rate-responsive modes

Pseudomalfunctions Pacing Modes Examples

Noise Reversion

MVP Mode

How PPM work and pseudo-malfunctions

Magnet Application on Medtronic Devices

Magnet Effect: Medtronic Pacemaker

• Magnet application over a PPM will cause the PPM to temporarily

function in an asynchronous magnet mode (DOO or VOO) at a rate

of either 85 or 65 depending on battery status.

Will Not Detect

Can Not Deliver Therapy

No effect on pacemaker function

Magnet Effect: Medtronic ICD

Magnet Effect on Medtronic ICD

• Results in:

o Temporary suspension of tachycardia detections. ICD will not deliver any

tachycardia or fibrillation therapies.

o NO effect on the pacemaker function of the device.

o Continuous Monitoring of the rhythm is required. If VT or VF develops,

remove the magnet and the device will detect and treat the arrhythmia.

o You may hear a constant tone for 15-30 seconds when the magnet is first

applied. If beeping occurs, the ICD should be checked.

Magnet OperationPacemaker vs. ICD

Medtronic

ICD

Medtronic

Pacemaker

Asynchronous pacing at 85 or 65 bpm

ICD detection temporarily inhibited

No permanent changes to device

programming

No effect on pacing therapy

EMI: A Real Patient Story• Patient came in contact with a gate at a lumber yard.

• When he first touched the gate, he felt the electrical

current and released his hand. This resulted in the

first aborted event.

EMI: A Real Patient Story (cont’d)• He then touched it again thinking everything was okay,

even though he continued to feel the leakage current.

The second time resulted in a therapy shock.

Sources of EMI in Hospitals

• Sources of EMI that may interfere with pacemaker and ICD operation include surgical/therapeutic equipment such as:

o Electrocauteryo Extracorporeal shock-wave lithotripsy o MRI o Therapeutic radiation o TENS unitso Transthoracic defibrillationo Tissue Expanders

HRS Consensus: Take Home Messages• Inactivation of ICD detection is not a universal requirement for all

procedures.

• Rendering PPMs asynchronous in PPM patients is not a universal

requirement of all procedures.

Crossley GH, Poole JE, Rozner MA, et al., “The Heart Rhythm Society (HRS)/American Society of Anesthesiologists (ASA) Expert Consensus

Statement on the Perioperative Management of Patients with Implantable Defibrillators, Pacemakers and Arrhythmia Monitors: Facilities and

Patient Management.” Heart Rhythm, 2011 July; 8(7): 1114-1154

HRS Consensus: Take Home Messages

• Risk of EMI depends on the type of medical procedure as well as clinical makeup of the patient.o Bipolar electrosurgery does not cause EMI unless it is applied directly to

the CIED.o Device reset occurs infrequently with electrosurgery.o Electrosurgery applied below the umbilicus is much less likely to cause

PPM or ICD interference than when applied above the umbilicus.o Lead tissue interface damage from external current is considered an

unlikely risk.

Crossley GH, Poole JE, Rozner MA, et al., “The Heart Rhythm Society (HRS)/American Society of Anesthesiologists (ASA) Expert Consensus

Statement on the Perioperative Management of Patients with Implantable Defibrillators, Pacemakers and Arrhythmia Monitors: Facilities and

Patient Management.” Heart Rhythm, 2011 July; 8(7): 1114-1154

“On/Off” Options for ICDs• If a magnet cannot be used to SUSPEND detections…

–A programmer should be acquired and the detections turned OFF

–This operation should be confirmed with the Cardiac Health Provider (written order required)

–The patient should be monitored and connected to an external defibrillator during the procedure

–Great care must be taken to ensure that the detections are turned back ON before the patient is unmonitored or leaving the facility

Post-op Considerations

Other Use of Magnet

• If a patient is in a pacemaker mediated tachycardia (PMT), placing a

magnet over the dual chamber pacemaker will stop the PMT by

forcing the pacemaker to an asynchronous paced mode.

• The asynchronous pacing mode will eliminate “tracking” of rapid

sensed atrial rhythms into the ventricle (often at the Upper Tracking

Rate) and the pacemaker-generated rhythm will slow

• If an SVT is in progress, the magnet rate will likely have little effect

on the rhythm

Stopping PMT With a Magnet

Case Study #1

A patient presents to the ER with the complaint that he is feeling

palpitations. You apply a magnet and see the following strip.

What is your interpretation?

Case Study #1

• You Observe:o ECG with magnet shows asynchronous VOO pacing at

65 bpm. o In Medtronic pacemakers, asynchronous pacing at 65

bpm with magnet application indicates Recommended Replacement Time (RRT)

• Next Steps:o Interrogate the device to confirm

the battery statuso Schedule a device replacement if RRT

has occurred

Case Study #1

• Conclusion:

o Device interrogation reveals a “Device has reached RRT:

Replace Pacer” message confirming the pacemaker battery

status

o Patient is scheduled for a device replacement

o He is also advised to comply with scheduled clinic follow-

ups and CareLink transmissions post-implant

Case Study #2

A 64 year old male was implanted with a Marquis DR ICD. You have

been called for a device check after a non-cardiac surgery during

which the patient received a shock via the ICD. During the procedure,

electrocautery was utilized. Patient was in normal sinus rhythm and

hemodynamically stable immediately preceding the ICD therapy.

Case Study #2 Screenshot

Case Study #2 Screenshot

Case Study #2 Screenshot

Case Study #2 Questions

• What do you see? According to the device, how fast was the patient’s rhythm before the delivered shock? (130ms)

• How fast was the patient’s actual rhythm? (620ms) How can you tell? (EGM 2 Vtip-Vring shows true V complexes)

• How do you account for the discrepancy? (noise/EMI)

• What steps can be taken to prevent future inappropriate shocks for this patient and future patients who have surgical procedures at the facility? (magnet use during surgery)

Key Learning Points• Both Pacemakers and ICD immediately resume normal function when magnet is

removed

• Use magnets to set pacemakers into asynchronous mode only if significant

inhibition is noticed

• Use of magnet to inhibit ICD therapy (when appropriate), is the safest protocol

for the patient

• Most of the time, there is no need to interrogate the device post-magnet use

Crossley GH, Poole JE, Rozner MA, et al., “The Heart Rhythm Society (HRS)/American Society of Anesthesiologists (ASA) Expert Consensus

Statement on the Perioperative Management of Patients with Implantable Defibrillators, Pacemakers and Arrhythmia Monitors: Facilities and

Patient Management.” Heart Rhythm, 2011 July; 8(7): 1114-1154

Carelink Express

CareLink Express Locations- WA

Locations Phone Number

Albany HeartCare 08 9842 2792

Armadale Hospital- ED and ICU 08 9391 2140

Broome Hospital- ED 08 9194 2392

Broome Regional Aboriginal Medical Service (BRAMS) 08 9192 1338

Bunbury Hospital- ICU 08 9722 1551

Bunbury HeartCare 08 9722 1679

Bunbury SJOG CCU 08 9722 1600

Busselton HeartCare 08 9754 0325

Dunsborough HeartCare 08 9756 8600

Carelink Express

• What it is

• Locations in WA

Locations Phone Number

Albany HeartCare 08 9842 2792

Armadale Hospital- ED and ICU 08 9391 2140

Broome Hospital- ED 08 9194 2392

Broome Regional Aboriginal Medical Service (BRAMS) 08 9192 1338

Bunbury Hospital- ICU 08 9722 1551

Bunbury HeartCare 08 9722 1679

Bunbury SJOG CCU 08 9722 1600

Busselton HeartCare 08 9754 0325

Dunsborough HeartCare 08 9756 8600

Location Phone number

Carnarvon Medical Service Aboriginal Corporation (CMSAC) 08 9941 2499

Esperance Hospital- ED 08 9071 0888

Geraldton- WACS 08 9965 8873

Joondalup- CCU 08 9400 9448

Kalgoorlie- Western Cardiology 08 9346 9300

Kununurra Ord Valley Aboriginal Health Service (OVAHS) 08 9168 1288

Murdoch- Western Australia Cardiology 08 9366 1888

Rockingham- ED 08 9599 4781

Questions?