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Emergency Medicine

Beyond Left Bundle Branch Block

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JAMA Internal Medicine

Published Online: July 25, 2022

Challenges in Clinical Electrocardiography

Article Information and Disclosures

Rimmy Garg, MD¹;

Sudhir Mungee, MD^1,2;

Mazen M. Kawji, MD²

Author Affiliations

¹University of Illinois College of Medicine at Peoria, Peoria
²OSF Healthcare Cardiovascular Institute, Peoria, Illinois

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A patient in their 80s with a history of atrial fibrillation, hypertension, and hyperlipidemia presented to a rural hospital with sudden-onset chest pain and shortness of breath. For the prior few weeks, the patient had had intermittent chest pain that resolved with rest but was now persistent. The patient had no history of coronary artery disease (CAD). The physical examination was notable for tachycardia, 3/6 mid systolic ejection murmur, and significant pedal edema. An electrocardiogram (ECG) was obtained (Figure).

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The aVR lead of the ECG has historically been ignored.¹ However, it is helpful in the diagnosis and prognosis of many clinical situations, including acute coronary syndrome, left ventricular aneurysm, Takotsubo syndrome, supraventricular and wide-complex tachycardias, Brugada syndrome, pericarditis, tricyclic toxic effects, and pulmonary embolus.¹^,2

An STE in lead aVR with diffuse STD (sometimes called the aVR sign) may indicate severe left main stenosis or multivessel CAD. The higher the STE in aVR, the higher the mortality.³ An AMI due to severe proximal LAD stenosis may cause STE in aVR; however, STE in V₁ will exceed that in aVR, and diffuse STD is less common. This patient’s ECG may be similar to a variant type of inferior myocardial infarction reported by Aslanger et al.⁴ The pattern includes STE in lead III (but not leads I or II) along with STE in aVR and lateral STD in the presence of severe multivessel CAD. However, in the variant pattern described by Aslanger et al,⁴ STD is absent in lead V₂, but it was present in this patient. The etiology for the STE in aVR was probably either reciprocal changes caused by STD in the anterolateral leads and/or infarction of the basal septum.

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Article Information

Corresponding Author: Mazen M. Kawji, MD, St Margaret's Health, 925 West St, Peru, IL 61354 (muhamed.m.kawji@osfhealthcare.org).

Published Online: July 25, 2022. doi:10.1001/jamainternmed.2022.2804

Conflict of Interest Disclosures: None reported.

Additional Contributions: We thank Victoria O’Brien Martian, the electrocardiogram technician who helped us acquire the electrocardiogram for this patient. She was not compensated for her contributions.

References

Gorgels APM , Engelen DJM , Wellens HJJ . Lead aVR, a mostly ignored but very valuable lead in clinical electrocardiography. J Am Coll Cardiol. 2001;38(5):1355-1356. doi:10.1016/S0735-1097(01)01564-9 PubMed Google Scholar Crossref

Chenniappan M , Sankar RU , Saravanan K . Lead aVR—the neglected lead. J Assoc Physicians India. 2013;61(9):650-654.PubMed Google Scholar

Yamaji H , Iwasaki K , Kusachi S , et al. Prediction of acute left main coronary artery obstruction by 12-lead electrocardiography. ST segment elevation in lead aVR with less ST segment elevation in lead V(1). J Am Coll Cardiol. 2001;38(5):1348-1354. doi:10.1016/S0735-1097(01)01563-7 PubMed Google Scholar Crossref

Aslanger E , Yıldırımtürk Ö , Şimşek B , et al. A new electrocardiographic pattern indicating inferior myocardial infarction. J Electrocardiol. 2020;61:41-46. doi:10.1016/j.jelectrocard.2020.04.008 PubMed Google Scholar Crossref

Sgarbossa EB , Pinski SL , Barbagelata A , et al. Electrocardiographic diagnosis of evolving acute myocardial infarction in the presence of left bundle-branch block. GUSTO-1 (Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries) Investigators. N Engl J Med. 1996;334(8):481-487. doi:10.1056/NEJM199602223340801 PubMed Google Scholar Crossref

Smith SW , Dodd KW , Henry TD , Dvorak DM , Pearce LA . Diagnosis of ST-elevation myocardial infarction in the presence of left bundle branch block with the ST-elevation to S-wave ratio in a modified Sgarbossa rule. Ann Emerg Med. 2012;60(6):766-776. doi:10.1016/j.annemergmed.2012.07.119 PubMed Google Scholar Crossref

Di Marco A , Rodriguez M , Cinca J , et al. New electrocardiographic algorithm for the diagnosis of acute myocardial infarction in patients with left bundle branch block. J Am Heart Assoc. 2020;9(14):e015573. doi:10.1161/JAHA.119.015573 PubMed Google Scholar Crossref

Kawji MM , Glancy DL . Repeat the electrocardiogram! Am J Cardiol. 2017;119(5):816-817. doi:10.1016/j.amjcard.2016.11.014 PubMed Google Scholar Crossref

Kawji MM , Glancy DL . Inferior Q waves and left bundle branch block. Am J Cardiol. 2015;116(5):822-823. doi:10.1016/j.amjcard.2015.05.056 PubMed Google Scholar Crossref

Horan LG , Flowers NC , Tolleson WJ . Thomas JR: the significance of diagnostic Q waves in the presence of bundle branch block. Chest. 1970;58(3):214-220. doi:10.1378/chest.58.3.214 PubMed Google Scholar Crossref

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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;
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