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HeartRhythm Journal CME December 2019: Isolated very low QRS voltage in the frontal leads predicts recurrence of neurally mediated syncope
Journal CME/HeartRhythm Journal
December 2019, Volume 16, Issue 12

The study was prompted by our observation that some patients with neurally mediated syncope (NMS) have an isolated QRS complex, of very low voltage (≤0.3 mV cutoff), in 1 of the frontal leads on the 12-lead electrocardiogram. The objective was to prospectively evaluate whether the presence of isolated very low voltage (VLV) predicts recurrence of NMS.
Dan Blendea MD PhD, FHRS - Nothing Relevant to Disclose
Craig A. McPherson MD - Nothing Relevant to Disclose
Sorin Pop MD - Nothing Relevant to Disclose
Jeremy N. Ruskin MD- Nothing Relevant to Disclose
Learning Objectives

Upon completion of this activity, participants will be able to:

1. Recognize the potential importance of the electrocardiogram in the workup for syncope.

2. Identify the presence of very low QRS voltage on electrocardiogram.

3. Relate concepts and knowledge regarding the mechanism of voltage generation on a 12-lead electrocardiogram.

4. Use concepts regarding mechanism of voltage generation during electrocardiogram analysis.

5.  Formulate a hypothesis relating the presence of very low QRS voltage on the 12-lead electrocardiogram and pathogenesis of neurally mediated syncope.

Target Audience
This activity is designed for all professionals who participate in the care and management of heart rhythm disorders.
The Heart Rhythm Society is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to provide continuing medical education for physicians.

The Heart Rhythm Society designates this journal-based CME activity for a maximum of 1 AMA PRA Category 1 Credit™.Physicians should claim only the credit commensurate with the extent of their participation in the activity.

CME Information
A CME Certificate (for physicians) or Certificate of Participation (for non-physicians) will be provided to individuals seeking credit from the following organizations which accept AMA PRA Category 1 Credit(s)™ or have identified credit awarded by ACCME accredited providers as being “substantially equivalent” to their own. Note that participants are advised to contact their certifying body for specific information regarding credit submissions:

· American Academy of Family Practice (AAFP) for elective credit

· American Academy of Nurse Practitioners Certification Board (AANPCB)

· American Academy of Physician Assistants (AAPA)

· American Nurses Credentialing Center (ANCC)

· American Osteopathic Association (AOA) for Category 2 credit

· Committee on Accreditation of Continuing Medical Education (Canada) 

· European Board of Accreditation in Cardiology (EBAC)

· European CME Credits (ECMEC)

· German Chambers of Physicians

· Oman Medical Specialty Board 

· Qatar Council for Health Practitioners 

· Royal College of Physicians and Surgeons of Canada 


The Heart Rhythm Society is committed to the provision of Continuing Medical Education (CME) that is balanced, objective, and evidence-based. The Heart Rhythm Society adheres to the Standards for Commercial Support (SCS) of the Accreditation Council for Continuing Medical Education (ACCME) which requires that those individuals in a position to control the content of an educational activity (including planners, faculty, authors, committee members, content reviewers, editors, and staff) disclose all relevant financial relationships (for self and for spouse/partner) with an ACCME-defined commercial interest within the 12 months prior to the disclosure.



Heart Rhythm Society takes steps to assure its learners and the public that the content of certified activities is accurate and reliable. The following principles are applied to the process of validating CME content. The content is peer-reviewed to ensure the following:

  • Fair Balance - that content is balanced among various options available for treatment and not biased toward a particular product or manufacturer.
  • Patient Treatment Recommendations - that patient treatment recommendations contained in the content are evidence-based, are appropriate for the target audience, and that the patient treatment recommendations contribute to overall improvement in patient care.
  • Scientific Validity - that scientific studies cited in the activity conform to standards accepted by the scientific community.
  • Learning Objectives - that the educational content supports the learning objectives of the activity, and that the objectives stated for performance-in-practice are actionable and measurable.
  • Omission and Commission - are there any studies, data, or best evidence that is missing?


Successful completion of this CME activity, which includes participation in the evaluation component, enables the participant to earn up to 1 MOC point in the American Board of Internal Medicine's (ABIM) Maintenance of Certification (MOC) program. Participants will earn MOC points equivalent to the amount of CME credits claimed for the activity. It is the CME activity provider's responsibility to submit participant completion information to ACCME for the purpose of granting ABIM MOC credit.


Successful completion of this CME activity, which includes participation in the activity, with individual assessments of the participant and feedback to the participant, enables the participant to earn up to 1 MOC point in the American Board of Pediatrics’ (ABP) Maintenance of Certification (MOC) program. It is the CME activity provider’s responsibility to submit participant completion information to ACCME for the purpose of granting ABP MOC credit.

Instructions for accessing HeartRhythm articles
Unless the CME article is tagged as Open Access or freely available, journal access is a benefit of HRS membership. However, non-members may purchase article access through Elsevier.


If you are an HRS member, here is how to access your journal subscription through the Heart Rhythm Society website:

  • Click LOG IN on the HRS homepage (
  • Once logged in, click your name in the upper right corner (next to the DONATE tab)
  • Click the HeartRhythm Journal link on the drop-down list
  • If the HRS login worked, you will see a green box below the banner that states “Welcome, HRS member!...”
  • Click on the title of any journal article and you will have access to the full text

HRS members may also access HeartRhythm articles through an Elsevier login:

  • Go to the HeartRhythm homepage:
  • In the upper righthand corner, click ‘Claim subscription’
  • If you have an Elsevier profile, log in with your Elsevier username/password
  • If you do not already have an Elsevier account, you will need to click ‘Create an Account’
  • Once you create an account and are logged in, you will be taken back to the homepage, where you can click the ‘Claim Subscription’ link
  • Check the box that says ‘I receive my subscription through a society membership’
  • A new field, ‘Society/Group,’ will appear with a dropdown list of societies; select Heart Rhythm Society from the list
  • After selecting HRS on the Claim page, if a sample mailing label image is offered, please enter your own account number from your print label. Otherwise, enter your membership number.
  • Enter your last name and click ‘Activate Claim’
  • Once you claim access, you will be able to view the full contents of the website
  • For future logins, select “Login” (rather than HRS login) and enter your Elsevier username and password


If you are not an HRS member, and the article is neither Open Access nor tagged as freely available, you will need to purchase access through Elsevier.

  • After clicking on the article link, scroll down below the Abstract to the grey box that says “To access this article, please choose from the options below”
  • Choose “Purchase access to this article.” For $35.95, you can download the PDF and have 24 hours of online access.
Availability: Retired
Cost: FREE
Credit Offered:
No Credit Offered
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