1. ELECTROPHYSIOLOGY LAB
EP: The Shocking Truth!
Nursing Grand Rounds
June 15, 2011
Kris Martin, RN
Julie MacDonald, RN

2. in between the OLD ICU and
WHERE ARE WE?
Wyman Ground
in between the OLD ICU and
Radiation Oncology

3. What do we do? Pacemaker and ICD implants Electrophysiology Studies
TEE’s
Cardioversions (Electrical and Chemical)
Yearly Defibrillator testing
Ablations- Atrial flutter and SVT, AVNRT
Tilt-Table Testing
Pacemaker/ICD Clinic

4. Why an EP study?
Diagnoses abnormal heart rhythms and/or induces cardiac arrhythmia's in order to:
Determine the source of arrhythmia symptoms
evaluate the effectiveness of certain medications in controlling the heart rhythm disorder
predict the risk of a future cardiac event, such as Sudden Cardiac Death
assess the need for an implantable device (ICD or pacemaker) or treatment procedure (ablation)
copyright Heart Rhythm Society 2004

5. An Overview of the Procedure
Pt receives conscious sedation and local anesthesia.
Femoral VEIN is accessed-one or both sides.
EP catheters are guided under fluoroscopy to the right atrium and ventricle via the IVC.
Electrodes at catheter tip collect data from various points in the heart (electrical mapping).
Various arrhythmia's can then be induced or ablated, or the decision to implant a pacemaker or ICD can be made.

6. We Maintain a Sterile environment, same as the OR

7. Ablations
Radio frequency energy is delivered through EP catheters to burn a small section of the myocardium.
This prevents the arrhythmia from continuing or returning.
At Mount Auburn, we do SVT and Atrial flutter ablations (Afib and VT ablations are not done here).
EP studies and ablations are typically done as outpatient procedures.

8. These are EP catheters seen on X-ray
HIS CS RV

9. TEE Transesophageal echocardiogram
Ultrasound probe passed into esophagus-posterior view of heart.
Diagnoses thrombus, valve disease, septal defects
?source of embolus, bacteremia, or CVA/TIA.
Pre-cardioversion to rule out existing thrombus.
Patients get conscious sedation and generally need to remain NPO for 4 hours after.

11. Cardioversion Synchronized shock to terminate Afib or flutter.
Pts receive MAC (monitored anesthesia care-propofol) by anesthesiologist
Chemical Cardioversions are when medications are given like Ibutilide or
Flecainide and EKG is monitored for conversion and arrhythmia.

12. Defibrillator Testing
DFTs: defibrillator threshold testing.
Usually done on ICD implant and yearly, or if there is a potential device/lead issue.
Frequently outpatient basis.
Patient receives MAC (propofol).
The ICD programer is used to induce VF and looks for the device to deliver a shock.

13. ICD Pacemakers with leads

14. Pre-op Pacemaker/ICD implant
Pt must be NPO after midnight
No applesauce with meds or
OJ for low blood sugar!
AM meds are okay with a small sip of water
Meds to hold:
heparin, multivitamins, oral hypoglycemics, insulin
Check blood sugar if diabetic
**LEFT sided IV**

15. Post-OP Care of Pacemaker/ ICD
Watch site for S+S infection
pt will have prophylactic antibiotic
Watch site for hematoma or bleeding
Moderate amount of bleeding on DSD okay
Bedrest usually for 12 hours post op
Pain: Manual manipulation during implant Percocet or Tylenol

16. this helps prevent dislodgment of leads!
Post Op Care
Keep arm in sling overnight, affected arm stays lower than shoulder height, no extended reaching
this helps prevent dislodgment of leads!
Next day chest X-ray to confirm lead placement, and device interrogation.
Pt will have a Green/purple folder in chart to take home. Please make sure to give them to patient on discharge
Call MD regarding procedure site, orders, function
of pacemaker.

17. Leads... Thin wires with flexible silicone coating
Connect the pacemaker generator to the myocardium
Sensing of heart activity and discharge of electrical impulse.

18. Leads are screwed into myocardium.
6-8 weeks for lead to mature: scar tissue forms around the lead and anchors it.
Extended reaching or lifting during this time may dislodge the lead requiring re-do.

20. Pacemaker leads as seen on Xray- (Dual chamber system)
Atrial lead
Ventricular leads

21. Pacemakers and defibrillators are a complicated
business and that is why we have specialists.
As a nurse you can not figure out what a
pacemaker or ICD is doing by just looking
at the monitor.
There are a few things that you should know that
will help you decide what to do.

22. What is a pacemaker or Defibrillator?
Pacemaker is sensing and monitoring patients own heart rate and delivers an impulse in either the atrium or ventricle in the absence of a sensed beat.
Defibrillator is sensing and monitoring the patients own heart rate for a fast rate usually set 188bpm to deliver a shock to convert to NSR. Can also pace if heart rate is slow usually 40 bpm.

23. What do you need to know? How many leads does the pacemaker have?
1 lead only sees what is happening in its chamber so a VVI pacemaker only knows what is happening in ventricle.
2 leads sees what is happening in both chambers the atrium and ventricle. Mode DDD/ DDI
What is the lower rate set at?
If it is 60 it will not pace if heart rate is
greater than 60bpm.

24. A Dual chamber pacemaker or DDD will pace
in Atrium at lower rate and then that sets up a timing
cycle for the Ventricle to either pace or inhibit.
In a DDD pacemaker you can see all different types of
pacing on EGM strips:
A sensed V sensed = NSR/ AFIB, pacemaker is inbitited
A paced V sensed = Sinus bradycardia
A sensed V paced = Heart blocks / CHB/2:1 block
A paced V paced = Heart block/Sinus arrest/asystole

25. Where will you find all this information?
You will find it in Meditech under Cardiology
Reports tab.
If there is no report then they have not been seen
at Mount Auburn Hospital Pacemaker Clinic.
Ask the patient/family if they have an ID card for their
pacemaker. Which will identify the manufacturer.
Call pacemaker 5622 to evaluate the device.

26. Pacemaker Report Pacemaker Report Clinic Tel: 617/499-5628
_____________________________________________________________________________
Date of Pacemaker check: 03/14/11
Pacemaker Type: Medtronic Sensia Implanted: 09/10/09
Pacemaker programmed rate: 70bpm Mode: DDDR
Response with magnet: Asynchronous pacing 3 at 100bpm then 85bpm
Presenting Rhythm: AV Paced
Underlying Rhythm: HB with PVC Pacemaker Dependent: N
Arrhythmia Recorded on Diagnostics: None
Battery Life Stable: Y
Impedance: A= ohms RV= ohms
Sensing: P-wave= mv R-wave= mv
LOC: A= @ ms RV= @ ms
Comments: In-house s/p fall. Appropriate sensing and capture testing. No
arrhythmia's recorded. Unable to promote intrinsic rhythm with AVD
at max, no changes made. Reprogramming for testing only. Follow
up in six months.

27. When would you apply a magnet to a pacemaker?
During electrocautery use in OR or GI Unit.
In a pacemaker a magnet causes the pacemaker to
Asynchronously pace at a set rate usually 85bpm-100bpm
What does this mean?
It means that the pacemaker can no longer see what the
patients heart is doing and is going to pace at the magnet rate.
If the patient is pacemaker dependent or has a HR below
then you need to apply a magnet. If a magnet is not
applied it could result in long pauses or asystole.

28. What if the patient has a Higher HR?
If a patient has their own HR then you would not apply
a magnet since asynchronous pacing could cause a
pacing spike to come in on a T-wave resulting in VT!
Remember when you place the magnet on a pacemaker
it can no longer see what the patient’s own heart is doing
A magnet should be available to place over device if
inhibition of pacing occurs resulting in pauses.

29. When do you call pacemaker clinic?
This device is over sensing and thinks it
sees ventricular activity and inhibits
pacing.

30. What you might see on monitor
Normal function
Non Sensing of R wave
Non Capture

31. What do you need to know about an ICD?
You need to know if it is a single (VVI) or dual chamber(DDD) device and the lower rate.
You need to know what the Zones are set at. VT zone or VF zone.
The magnet response will always be: Inhibits therapies, no effect on pacemaker.
If they are pacemaker dependent,they will need to be reprogrammed for surgery to an Asynchronous
mode

32. What do you need to know about a ICD?
That it can overdrive pace a patient out of a fast HR if it falls into the VT zone.
That it is not always able to distinguish between AFIB and VT especially if it is a single lead device. A VVI device doesn’t know what the atrium is doing.
You can put a magnet over ICD to disable the therapies and prevent or stop inappropriate shocks.

33. ICD Report

34. This is what a magnet looks like some are blue
You can find them on all the code carts throughout
the hospital, in the OR and GI units.
When would you place a magnet over an ICD?
If a patient is getting inappropriate shocks.
During cautery in OR or GI unit.
CMO status until device can be reprogrammed.
A Doctors Order is need to apply a Magnet and
disable a device.

35. ICD Patients that are Pacemaker Dependent
If they are pacemaker dependent,they will need to be
reprogrammed for surgery to an Asynchronous mode.
Remember that a Magnet only Inhibits therapies, has no effect on Pacemaker in an ICD Patient.
How do you know if they are pacemaker dependent?
Look at the report in Meditech.
you will need to call Pacemaker clinic 5622 to arrange for someone to come and evaluate device and reprogram if necessary.

36. In OR, GI unit when cautery is being used the ICD
should be disabled by a magnet.
Electrocautery can cause noise on the lead,
an ICD would interpret it as fast heart rate and deliver
an inappropriate shock.
The patient should always be on a monitor when
the magnet is in place.
The benefit of this is that if a VT/ VF episode
occurs you can remove the magnet and the device
will deliver a shock. If the device was programmed
OFF then would need to externally shock
the patient. .

37. This is an example of noise
on an ICD lead from Cautery.
The device thinks this is VF and would deliver a shock if
a magnet was not applied.

38. You can always call clinic, 5622 and
we will help you figure it out!

39. If a patient has been made CMO you may place a
magnet over device until it can be reprogrammed.
A note must be in the chart from attending physician
that it has been discussed with patient and or family.
An order must be written to turn off ICD, before it can be done. If you are applying a magnet an order should be written.
This has no bearing on pacemaker portion of ICD and we do NOT turn off pacemakers in CMO patients.

40. When would you apply a magnet to an ICD?
If a patient was receiving shocks that you/MD determine to be inappropriate you may apply a magnet to stop the therapies/shocks.
An example of this would be a patient who is in rapid AFIB with ventricular rate in 190bpm and has a single chamber device with a VT zone set for 188bpm. The ventricular lead only knows that the rate is above 188bpm and that it is programmed to give a shock.

41. Another example of when to place a magnet is
the patient is telling you they are getting Shocked
and this is the rhythm on monitor/EKG.
This is NSR and if the patient is getting shocks
from ICD, then you need to disable it with a magnet
The lead is most likely broken and over sensing
the device will continue to give shocks until it is
disabled.

42. What if the device is not giving a shock and you see VT
on monitor?
The device will only do what it has been programmed to do
If a VT Zone is set at 188bpm and a patient is in a
180bpm the device is never going to give a shock.
You would need to externally shock the patient.
The pads should be placed to avoid damaging the ICD.

43. What if your patient tells you his device is BEEPING
or VIBRATING in their Chest?
They are NOT crazy! The devices are set up to alert patients
of a problem.
You should notify the pacemaker clinic or cardiologist on call. They can call in a company representative to interrogate and find the problem.
The beeping and or vibrating will continue every 6-10hours until device is reprogrammed.
8am pm pm

44. Why is Pacemaker/ ICD follow-up important?
We often find new onset AFIB. Device can date and time
the event, amount and duration of episodes and give atrial
and ventricular rates.

45. We evaluate Histograms to tell us if the heart rate has been
fast or if it has been stuck at the lower rate. Medications are
often adjusted or Rate Response added.

46. We find broken leads or batteries that need replacement.
Non capture or
intermittent
capture
broken lead on
x-ray
Thrombus/emboli

47. We find non-sustained episodes of VT in pacemaker
patients that otherwise would go undetected. This could
be causing them dizziness or syncope.
New onset Afib is common to find also.

48. In an ICD we can find episodes that received ATP or a shock
In an ICD we can find episodes that received ATP or a shock. After reviewing with the cardiologist, their meds may be adjusted to prevent further therapies.

49. In an ICD we can find episodes of AF getting inappropriate
therapies. Medications would be evaluated and adjusted.
Atrial
vent
shock

50. This is another example
of inappropriate shock for
Sinus Tachycardia
and the patient should
have medications adjusted
to prevent their sinus rate
from going this high.

51. THANK YOU FOR COMING
The EP Staff
QUESTIONS?