[Skip to Content]
[Skip to Content Landing]

A Woman With Syncope and Frequent Premature Ventricular Contractions

Educational Objective
Based on this clinical scenario and the accompanying image, understand how to arrive at a correct diagnosis.
1 Credit CME

A woman in her late 60s presented to the emergency department after an episode of syncope. She described several other episodes occurring at rest over the past several weeks. She denied palpitations, chest pain, and shortness of breath. She was otherwise in excellent health and not taking any medications. She had no family history of syncope or sudden death. Her vital signs and physical examination were unremarkable. The initial electrocardiogram (ECG) results were normal, but premature ventricular contractions (PVCs) were noted on telemetry. Shortly thereafter, 2 episodes of fast polymorphic ventricular tachycardia (PVT), 30 minutes apart, were recorded, both lasting less than 4 seconds (Figure 1A). A repeat ECG showed PVCs (Figure 1B). Laboratory test results including serum potassium and magnesium as well as 3 serial troponin levels were normal. Echocardiography showed normal left ventricular systolic function without wall motion abnormalities or valvular abnormalities. Coronary angiography showed a 50% stenosis of the left circumflex artery. Instant wave-free ratio across the stenosis was 1.0.

Please finish quiz first before checking answer.

You answered correctly!

Read the answer below and download your certificate.

You answered incorrectly.

Read the discussion below and retake the quiz.

Short-coupled PVCs initiating PVT

A. Implant a defibrillator

The ECG in Figure 1B shows normal sinus rhythm with a normal axis, sinus arrhythmia, nonspecific P wave abnormality, and minor nonspecific T wave changes. There are frequent uniform PVCs with a right bundle branch block morphology and a right superior axis. Retrograde P waves following the PVCs are noted. The PVCs are superimposed on the T waves, most notably in lead aVF (the PVCs start after the peak of the T wave), consistent with the R-on-T phenomenon, with a short coupling interval of approximately 330 milliseconds.

PVCs with short coupling intervals have been shown to trigger PVT and ventricular fibrillation in patients with structurally normal hearts, which can lead to syncope and sudden cardiac death. The episodes of PVT shown in Figure 1A are initiated with a PVC that has an identical morphology and coupling interval to the PVC occurring few beats earlier. The QT interval is not prolonged. There is no coved ST-segment elevation in V1 through V2 to suggest Brugada syndrome. No ST-segment elevation precedes runs of PVT, ruling out coronary spasm as the etiology.

Survey Complete!

Sign in to take quiz and track your certificates

Buy This Activity
Our websites may be periodically unavailable between 7:00pm CT June 10, 2023 and 1:00am CT June 11, 2023 for regularly scheduled maintenance.

JN Learning™ is the home for CME and MOC from the JAMA Network. Search by specialty or US state and earn AMA PRA Category 1 Credit(s)™ from articles, audio, Clinical Challenges and more. Learn more about CME/MOC

CME Disclosure Statement: Unless noted, all individuals in control of content reported no relevant financial relationships. If applicable, all relevant financial relationships have been mitigated.

Article Information

Corresponding Author: Mazen M. Kawji, MD, OSF Cardiovascular Institute, 1050 E Norris #1A, Ottawa, IL 61350 (muhamed.m.kawji@osfhealthcare.org).

Published Online: May 17, 2023. doi:10.1001/jamacardio.2023.1053

Conflict of Interest Disclosures: None reported.

References
1.
Fastier  FN , Smirk  FH .  Some properties of amarin, with special reference to its use in conjunction with adrenaline for the production of idio-ventricular rhythms.   J Physiol. 1948;107(3):318-331. doi:10.1113/jphysiol.1948.sp004276PubMedGoogle ScholarCrossref
2.
Smirk  FH .  R waves interrupting T waves.   Br Heart J. 1949;11(1):23-36. doi:10.1136/hrt.11.1.23PubMedGoogle ScholarCrossref
3.
Moe  T .  A case of Morgagni-Adams-Stokes attacks caused by transient recurrent ventricular fibrillation without apparent organic heart disease.   Acta Med Scand. 1948;130(5):416-435. doi:10.1111/j.0954-6820.1948.tb10076.xPubMedGoogle ScholarCrossref
4.
Storstein  O .  Adams-Stokes attacks caused by ventricular fibrillation, in a man with otherwise normal heart.   Acta Med Scand. 1949;133(6):437-441. doi:10.1111/j.0954-6820.1949.tb09547.xPubMedGoogle ScholarCrossref
5.
Bikkina  M , Larson  MG , Levy  D .  Prognostic implications of asymptomatic ventricular arrhythmias.   Ann Intern Med. 1992;117(12):990-996. doi:10.7326/0003-4819-117-12-990PubMedGoogle ScholarCrossref
6.
Massing  MW , Simpson  RJ  Jr , Rautaharju  PM , Schreiner  PJ , Crow  R , Heiss  G .  Usefulness of ventricular premature complexes to predict coronary heart disease events and mortality.   Am J Cardiol. 2006;98(12):1609-1612. doi:10.1016/j.amjcard.2006.06.061PubMedGoogle ScholarCrossref
7.
Lown  B , Wolf  M .  Approaches to sudden death from coronary heart disease.   Circulation. 1971;44(1):130-142. doi:10.1161/01.CIR.44.1.130PubMedGoogle ScholarCrossref
8.
Conte  G , Belhassen  B , Lambiase  P ,  et al.  Out-of-hospital cardiac arrest due to idiopathic ventricular fibrillation in patients with normal electrocardiograms.   Europace. 2019;21(11):1670-1677. doi:10.1093/europace/euz221PubMedGoogle ScholarCrossref
AMA CME Accreditation Information

Credit Designation Statement: The American Medical Association designates this Journal-based CME activity activity for a maximum of 1.00  AMA PRA Category 1 Credit(s)™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Successful completion of this CME activity, which includes participation in the evaluation component, enables the participant to earn up to:

  • 1.00 Medical Knowledge MOC points in the American Board of Internal Medicine's (ABIM) Maintenance of Certification (MOC) program;;
  • 1.00 Self-Assessment points in the American Board of Otolaryngology – Head and Neck Surgery’s (ABOHNS) Continuing Certification program;
  • 1.00 MOC points in the American Board of Pediatrics’ (ABP) Maintenance of Certification (MOC) program;
  • 1.00 Lifelong Learning points in the American Board of Pathology’s (ABPath) Continuing Certification program; and
  • 1.00 credit toward the CME [and Self-Assessment requirements] of the American Board of Surgery’s Continuous Certification program

It is the CME activity provider's responsibility to submit participant completion information to ACCME for the purpose of granting MOC credit.

Close
Want full access to the AMA Ed Hub?
After you sign up for AMA Membership, make sure you sign in or create a Physician account with the AMA in order to access all learning activities on the AMA Ed Hub
Buy this activity
Close
Want full access to the AMA Ed Hub?
After you sign up for AMA Membership, make sure you sign in or create a Physician account with the AMA in order to access all learning activities on the AMA Ed Hub
Buy this activity
Close
With a personal account, you can:
  • Access free activities and track your credits
  • Personalize content alerts
  • Customize your interests
  • Fully personalize your learning experience
Education Center Collection Sign In Modal Right
Close

Name Your Search

Save Search
With a personal account, you can:
  • Access free activities and track your credits
  • Personalize content alerts
  • Customize your interests
  • Fully personalize your learning experience
Close
Close

Lookup An Activity

or

My Saved Searches

You currently have no searches saved.

Close

My Saved Courses

You currently have no courses saved.

Close