[Skip to Content]

Quiz

Cardiology

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

JAMA Cardiology

Published Online: May 17, 2023

JAMA Cardiology Clinical Challenge

Article Information and Disclosures

Mazen M. Kawji, MD^1,2

Author Affiliations

¹OSF Cardiovascular Institute, Peoria, Illinois
²St Elizabeth Hospital, Ottawa, Illinois

Read article on JAMA Network

Read Case Take Quiz Answer

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.

Take Quiz

Please finish quiz first before checking answer.

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.

Sign in to take quiz and track your certificates

Buy This Activity

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

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.sp004276 PubMed Google Scholar Crossref

Smirk FH . R waves interrupting T waves. Br Heart J. 1949;11(1):23-36. doi:10.1136/hrt.11.1.23 PubMed Google Scholar Crossref

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.x PubMed Google Scholar Crossref

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.x PubMed Google Scholar Crossref

Bikkina M , Larson MG , Levy D . Prognostic implications of asymptomatic ventricular arrhythmias. Ann Intern Med. 1992;117(12):990-996. doi:10.7326/0003-4819-117-12-990 PubMed Google Scholar Crossref

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.2006.06.061 PubMed Google Scholar Crossref

Lown B , Wolf M . Approaches to sudden death from coronary heart disease. Circulation. 1971;44(1):130-142. doi:10.1161/01.CIR.44.1.130 PubMed Google Scholar Crossref

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/euz221 PubMed Google Scholar Crossref

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.