Biventricular Pacemaker For Non-Obstructed HCM Patients?

A small study of  29 patients conducted recently in the U.K. found that the use of a biventricular pacing  in patients with non-obstructive hypertrophic cardiomyopathy improved symptoms of breathlessness and improved exercise capacity as demonstrated during oxygen consumption testing.

Medications are the only treatments currently available to non-obstructed patients. The authors of this study hypothesized that biventricular pacing could be a viable way to address exercise limitations in non-obstructed patients if medications have been ineffective.

Larger trials may establish biventricular pacing as a viable treatment for non-obstructed patients in the future.

Guest Blogger Doug Rachac – Magnets and Airports: Should ICD Patients Be Afraid?

Editor’s Note:  Doug Rachac found out that he himself needed an ICD while employed by device manufacturer Medtronic.  He now uses his personal experiences to help other device patients learn how to live happily with their implantable devices.  

 

When cardiac patients receive a pacemaker or defibrillator, they often have questions about their new “friend.”  They wonder if this new device has limitations, and what those limitations might be.

And they may find that the internet can be, at the same time, both helpful and misleading.  Accurate information is out there, but separating truth from fiction is the hard part.  To learn the truth, patients turn to their doctors, nurses and clinic device techs for answers, not realizing that sometimes these professionals also give advice based on outdated or incorrect information.

When a patient wants to know if it is safe to scuba dive with their heart condition, they should ask their physician. However, if they want to know how deep it is safe for them to dive with their specific implanted device, instead of asking their physician, they should instead direct their question to the engineers of the device manufacturer who designed and tested the device.

Patients should speak with their doctor to learn if their health condition limits them from certain physical activities (such as scuba diving), but questions about the limitations or capabilities of devices and leads should usually first be directed to the manufacturer of the device – the best source of up-to-date, accurate information.  Whenever I am looking for up to date, accurate information about my device, I start with Medtronic, the manufacturer of my implanted device.

Patients can easily find the make and model of their device, as well as learn how to contact their device manufacturer, by calling the Patient Services number located on their Patient ID card.

In this blog article, I’d like to share with you some information regarding two of the most common misconceptions relating to implantable devices out there:  1) magnets are dangerous to implanted devices like pacemakers and defibrillators; and 2) it is unsafe to walk through airport/venue security.

All of the information I discuss below can be found, if you dig deep enough, on each specific manufacturer’s websites.

Magnets: Should We Be Afraid?

All companies advise patients to keep magnets at least 6-8 inches away from their devices for their safety.  But the simple answer to the question is NO!  You do not need to be afraid of magnets.  However, you do need to be aware of how a magnet interacts with your device when you come into contact with one.

A magnet will NOT:

  • Scramble the device programming
  • Turn the device off
  • Turn off pacing
  • Damage the device in any way

These common misconceptions are based on devices that are over 10 years old, or are based on a misunderstanding of the truth. In most industry devices a magnet will interact with a pacemaker and defibrillator in the following ways:

Pacemaker or Cardiac Resynchronization Therapy Pacemaker (CRT-P):

A magnet placed on or near a pacemaker/CRT-P device will force the device to pace at a constant, preset rate.  Different companies have different preset rates.  Medtronic is set to pace 100% of the time at 85 beats per minute (BPM).  When the magnet is moved away from the device, the device will immediately revert back to the programming that was input by the doctor or device tech at implant, or that was modified during a subsequent interrogation session.

Defibrillator or Cardiac Resynchronization Therapy Defibrillator (CRT-D):

In most industry devices, a magnet will “inhibit detection” which is a fancy way of saying the device won’t shock you if needed.  Once the magnet is removed, the shock function reverts back to normal.

This function is a normal design feature of the devices designed for use by clinicians and doctors.  In both types of devices, a magnet will in no way harm the device or alter the programming.  The effect of the magnet is only temporary.  Once the magnet is moved 6-8 inches away from the device, the device’s normal programming will resume.  Some everyday items such as iPad covers, purses, and children’s toys may contain magnets which are strong enough to trigger the magnet response in our devices. However, simply moving those items 6-8 inches away from your device will resolve the issue.  Remember, even if you do encounter a strong magnet or magnetic field, it will not harm your device in any way.  Simply move away from the magnet/magnetic field and your device will return to its normal operations.

Let me reiterate: a magnet will in no way harm your device, shut it off, or alter the programming.

Airport/Venue Security:

There was a time when walking through airport or venue security with an implanted device was considered dangerous.  This was back when our devices included an electrical component called a Reed Switch.  But, over a decade ago, devices evolved after safety issues forced industry to eliminate the Reed Switch in all implanted devices.  At the same time, a new international standard emerged setting limits for how much magnetic energy an implanted device needed to be able to withstand.  The level is high enough that most forms of magnetic energy encountered in our daily lives are insufficient to interact with our devices in any meaningful way.  There are a few exceptions, such as the electromagnetic energy generated by a hydroelectric dam.  But, airport archways and hand wands do not generate that level of energy.  Companies like Medtronic simply suggest that a patient walk through the airport archway at a normal pace, and that wands are not waved repeatedly over the device multiple times.  Aside from those precautions, patients do not need to avoid airport or venue security in any way.  Millimeter wave scanners (the one that rotates around you) are also safe to use.

Let me say it again: Pacemaker/ICD/CRT patients do not need to fear airport/venue security checkpoints.  Simply walk through the archway at a normal pace, and ask that wands not be waved back and forth over the device repeatedly.

Living with our devices can be stressful enough.  It’s my belief that having accurate information is the first step in being able to live the life we want to live, not the life we think we are now forced to live.

My physician was clear when he said, “Your device is there to protect you and allow you to live your life.  It is not there to restrict you in any way.”

It’s time to dispel the information of old, and to start living our lives without these old fears. Our devices have evolved over the years so we need not fear magnets or security lines any more.  If you would like to learn more about me and living with an implantable device, I have uploaded several videos to my YouTube Channel.  You can find specifically about  devices, magnetic fields and airport security here.

About Doug Rachac:

Doug Rachac received his implanted Medtronic defibrillator in 2014 due to several episodes of syncope and documented non-sustained ventricular tachycardia.  He spent 14 years working for Medtronic, where he worked in multiple areas, including Customer Service, Education, and Quality.  He left Medtronic in 2015 to recover, volunteer and to be the world’s best stay-at-home dad.  He now advocates for device patients and consults with the medical device industry on patient engagement and patient focused initiatives.  You can find him on Twitter @HankEPants.

Electric & Hybrid Cars: A Safe Choice for ICD & Pacemaker Patients

Car Shopping

Recently, I began shopping for a new car.  The process is overwhelming! There are so many factors to consider when looking for a new vehicle: gas mileage, sedans vs. hatchbacks, SUVs…the list goes on and on.  Electrics and hybrids are all the rage here in Southern California, but I wasn’t sure if they would be safe for me to drive because I have an implantable defibrillator which also functions as a pacemaker.

German Study: Safety of Popular European Electric Cars

Lucky for me, I didn’t have to wait too long for an answer to my question.  According to a recent German study published in the Annals of Internal Medicinepeople with implanted cardiac devices can safely drive the most common electric cars on the market today.  This study measured the magnetic field strength in four electric cars with the largest market share in Europe: the BMW i3, Nissan Leaf, Tesla Model 85S, and the Volkswagen e-up!  Though the study found that recent models of all of these cars were safe, the authors of this study did caution that future models could potentially cause interference with implantable cardiac devices, depending on  their design.

For more on the recent German study, see these articles at Reuters, Medical Xpress.com and TechTimes.

2017 AHA Preliminary Data – Tesla

The findings from the German study added to preliminary data presented at a 2017 meeting of the American Heart Association.

Tesla Charging

Participants’ devices were monitored for electromagnetic interference while they sat in or stood near a Tesla S P90D.  Testing was done with the study participants situated in a variety of positions—sitting in the driver’s seat, passenger seat, backseat and standing next to the charging port.

The study found that sitting in, or standing close to the charging port of a Tesla while the car was charging at a 220 volt charging station did not trigger an ICD shock or cause interference with the assorted implantable defibrillators. 

2013 Mayo Clinic Study – Toyota Prius

Lastly, Mayo Clinic cardiologists presented similar findings at the American College of Cardiology meeting in 2013.

56050078 - gray toyota prius hybrid - sideviewThat early study found no issues when patients implanted with ICDs and/or pacemakers drove a 2012 Toyota Prius hybrid at 30 mph, 60 mph and at variable speeds of acceleration and deceleration, as well as sitting in the driver’s seat, the front passenger seat, the left and right rear seats and in front of and behind the car from the outside.  Although the researchers found that the implantable devices were exposed to electromagnetic fields inside the car, the amount of interference wasn’t significant enough to cause problems with the devices.

For more on the 2013 Mayo study, see this article in Popular Science.

 

Now that I know that driving these cars is safe for me, I will be out on a test drive trying to narrow down my options!

Chapter 4: MRI Safety for ICD & Pacemaker Patients

Yet another study has confirmed the safety of MRIs in patients with non-MRI conditional ICDs and pacemakers.

The latest study, from the University of Pennsylvania and published in the New England Journal of Medicine, found no adverse effects from 1.5 Tesla MRI scans performed on 1509 patients who underwent a total of 2103 scans.  58% had pacemakers and 42% had ICDs.

This study confirms previous findings relating to the safety of MRIs in ICD and pacemaker patients reported by HCMBeat here and here.

You can also read my personal experience trying to get a brain MRI in Los Angeles last year here.

Chapter 3: MRI Safety for ICD & Pacemaker Patients

Long awaited results of the MagnaSafe study regarding the safety of MRIs in patients with implantable devices were published in February.   The MagnaSafe study established a multi-center prospective registry for patients undergoing MRI scans despite their having an implanted device not deemed safe for MRI scanning by the FDA.

Continue reading “Chapter 3: MRI Safety for ICD & Pacemaker Patients”

Safety of MRIs With Abandoned Leads

Two posters presented at this weekend’s Heart Rhythm Society meeting in Chicago show that patients who have abandoned pacemaker or ICD leads may safely undergo MRI exams.

These posters follow the earlier MagnaSafe study which demonstrated the safety of MRI for patients with pacemakers and ICDs, but which excluded patients with abandoned leads from the findings.

The first, by researchers at Mayo Clinic, included 57 patients with 63 abandoned leads who underwent 70 MRI exams in a 1.5 Tesla machine.  The authors saw no clinical problems and no device malfunction following the scans.

The researchers also monitored blood troponin levels in 35 of the patients following the scans and did not see any elevation which could indicate distress to the heart from the scan.

The second poster, from the University of Pennsylvania, involved 24 patients with abandoned leads who underwent 34 MRI exams.  The results of this study also failed to demonstrate any clinical problems or patient discomfort resulting from the MRI scans.

With any luck, everyone will soon be able to obtain an MRI and will not be denied due to any kind of implantable cardiac device.

For an account of my personal experiences seeking MRI with an ICD, read this.

Study Shows MRIs Safe for Pacemaker & ICD Patients

The long awaited results from the Magna-Safe study were published today in the New England Journal of Medicineand it was good news for pacer and implantable cardioverter–defibrillator (ICD) patients! When proper precautions have been taken, MRIs were found to be safe in patients implanted with certain older pacemakers or ICDs.

In order to study the safety of scanning these patients, doctors set up a prospective registry for patients undergoing MRI in scanners with a magnetic field strength of 1.5 tesla who were scanned despite having a non-MR conditional device (i.e. a device which had not been deemed safe for MRI scanning by the FDA).

MRIs were performed on 1000 patients with pacemakers and 500 patients with ICDs and the results of the study showed that as long as appropriate patient selection and safety protocols were followed, patients had no problems with the MRI scans.

This is indeed good news for those of us with older devices who may be in need of MRI scans. To read about my own experiences and investigation of this issue, read my previous blog entry YES WE SCAN! ICDs and MRIs.

Yes We Scan! ICDs and MRIs

Why MRI is Important:

Magnetic Resonance Imaging, or MRI, is one of the most important tools of modern medicine.  MRIs can be used to evaluate almost every kind of medical issue, from brain tumors to twisted ankles.  They provide clear images, and in some instances, also provide superior visualization.  Because they do not expose the imaging subject to radiation, they are generally preferred over CT scans, even when the two scans would reveal the same information.

MRI in HCM:

In the last several years, MRI has also become an important tool in the evaluation of hypertrophic cardiomyopathy (HCM).  The images resulting from MRI have proven superior in visualizing the size and structure of the heart and, when used with a contrast agent, MRIs are able to show the extent of scarring in the HCM heart.

MRI Hasn’t Been an Option for Many of Us:

MRI has been unavailable to those of us who have an implantable defibrillator or ICD to in order to protect us from sudden cardiac arrest.  Until recently, having an ICD was an absolute contraindication to MRI.  Newer MRI-safe ICD systems have been in use for the last few years, but that still leaves in place the contraindication for those of us who have older ICD units in place.  That problem is that older lead systems that were implanted along with old, non-MR compatible generators may be incompatible with the newer MR compatible technology, and it may not be possible to simply hook up these old leads to a new MRI compatible generator.  And, it is not as easy as you might think to extract old leads.  Scar tissue grows around these leads, making their removal an intricate and dangerous procedure that is best done only in carefully controlled circumstances by highly specialized physicians. Continue reading “Yes We Scan! ICDs and MRIs”

Abandoned Leads Harder to Extract

According to a recent study published in JACC: Clinical Electrophysiology, previously abandoned pacemaker and implantable defibrillator leads which have been capped off and left behind following replacement were harder to extract later.  These abandoned leads also made it more difficult to treat device infections.

When interviewed about the significance of these study results, several physicians knowledgeable in the field further emphasized that lead removal requires special skill and equipment not typical for the average physician who implants cardiac devices.  Hence, patients facing a potential lead extraction should consider their options carefully and seek care from a specialist in lead extraction.

 

Unsuspected AFib Detected in HCM Patients

A recent retrospective study published in the Journal of Cardiovascular Electrophysiology found that atrial fibrillation (AF) occurred for the first time in 16 of 30 patients (53%) of patients with implantable devices being followed at the center conducting the study.

Of the patients experiencing AF for the first time, 14 of 16 (88%) of the patients were not aware of having experienced any clinical symptoms.  As patients age, AF appears to be a common consequence of HCM.  Patients may be caught unaware and unprepared, so monitoring is especially important.